LT1840-7DFB1_技术文档

Rugged Environment

AC-DC Converters >100Watt

T Series

500 Watt AC-DC Converters

T Series

Input to output isolation

Single output

• Universal AC input range

• DC output voltage for 24 and 48 V loads

• Battery charging for 24, 36, 48 V batteries with re-

mote temperature control

• Telecom rectifier applications

• Immune to transients and disturbances according to

VDE 160 and IEC/EN 61000-4-2,-3,-4,-5,-6

• 4000 V AC input to output electric strength test

• Very high efficiency, typically 93%

• Power factor >0.96, harmonics <IEC/EN 61000-3-2,

low RFI

• No inrush current, hot plug-in capability

• High power density, 210 W/dm³, rugged mechanical

design

• Very compact 19" cassette (28 TE, 3 U, 160 mm),

111

4.4"

3 U

Safety according to IEC/EN 60950

LGA

141

5.6"

168

28 TE

6.6"

C

Summary

The latter types can be integrated into systems where the

output voltage is backed-up by batteries. The float charge

of the battery can be set by a cell voltage selector switch

according to the battery type used. Moreover these units

feature a temperature sensor input to improve the life ex-

pectancy of the battery.

The T series of converters are electrically isolated AC-DC

converters with an output power of up to 550 W. For higher

power requirements several units may be connected in

parallel.

The input of the T units is ideally adapted to the mains: Full

power factor correction, no inrush current, low RFI level and

high transient and surge immunity are key design features.

The T units behave similar to a resistive load.

The rectifier types suit for DC-bus applications at constant

voltage. As the output voltage is SELV, even electrically non

isolated switching regulators such as the Melcher PSR

types may be connected to the T output.

The L-input provides a universal AC-input range from

85...255 V AC. It is the preferred type for 230 V mains,

whereas the U-input range is optimized for 110/120 V

mains. The output delivers an electrically isolated Safety

Extra Low Voltage (SELV) and is short-circuit and no-load

proof. Depending on the type, two output characteristics

are available, intended either for rectifier applications or for

battery charging purposes.

The T 1701 types are especially optimized to build distrib-

uted power systems together with the Melcher CQ-series

DC-DC converters as the signalling capabilities of both

families are matched. Distributed power systems have as

one advantage less power loss over load lines and fewer

regulation problems.

Melcher offers also backplanes for fast and simple set-up of

19" rack systems with T units (see chapter: Back Planes).

Page

Table of Contents

Page

Functional Features ....................................................... 16

Auxilliary Functions ........................................................ 21

Electromagnetic Compatibility (EMC) ............................ 25

Immunity to Environmental Conditions........................... 26

Environmental Conditions .............................................. 27

Mechanical Data ............................................................ 28

Safety and Installation Instructions ................................ 30

Description of Options.................................................... 33

Accessories.................................................................... 33

Summary.......................................................................... 1

Type Survey and Key Data .............................................. 2

Type Key .......................................................................... 2

Sensor Type Key .............................................................. 3

Functional Description...................................................... 4

Electrical Input Data ......................................................... 5

Electrical Output Data of the Rectifier Version ................. 7

Electrical Output Data of Battery Charger Version......... 10

Control Features of the Battery Charger Version ........... 12

Temperature Sensors..................................................... 15

Edition 4/4.99

1/33

MELCHER

The Power Partners.

T Series

AC-DC Converters >100Watt

Rugged Environment

Type Survey and Key Data

Table 1: Type Survey (All typical values at 20°C)

Output voltage

Output current

Input voltage range and efficiency

Options

U_{o set}at U_{i nom}, ¹/

[V DC]

2

I_{o nom}

[A]

U_{i min}...U_{i max}

70...140 V AC

η_min

[%]

U_{i min}...U_{i max}

85...255 V AC

η_min

[%]

1

24.25

16

14.5

10

UT 1201-7 ^{2, 4}

UT 1240-7Z ^{4, 3}

UT 1701-7 ⁵

–

91

92

–

LT 1201-7 ^{2, 6}

LT 1240-7Z ^{6, 3}

LT 1701-7 ⁶

91

92

93

91

D

B1

25.25...27.25...28.25

54.5

48

11

LT 1702-7 ^{2, 6}

LT 1740-7Z ^{6, 3}

LT 1840-7Z ^{3, 6}

50.5...54.5...56.5

37.9...40.9...42.4

10

UT 1740-7Z ^{5, 3}

–

92

–

11

¹Efficiency measured at U_{i nom}and I_{o nom}

²Instead of output power limitation, output current limitation.

.

³Output voltage range controlled by input U_cr, remote temperature sensor and cell voltage selector switch.

⁴Reduced output power for U_i= 70...95 V AC. See Output Power Limitation.

⁵Reduced output power for U_i= 70...100 V AC. See Output Power Limitation.

⁶Reduced output power for U_i= 85...155 V AC. See Output Power Limitation.

Type Key

L T 1 7 40 -7 D Z F B1

Input voltage range U_i

70...140 V, 47...63 Hz ................................ U

85...255 V, 47...63 Hz ................................. L

Series ............................................................................... T

Number of outputs:........................................................... 1

Output U_{o set}

24, 27.25 V .................................................. 2

48, 54.5 V .................................................... 7

40.9 V .......................................................... 8

Recifier version .................................... 01, 02 ³

Battery charger version.............................. 40 ⁴

Other voltages .................................... 00...99

Ambient temperature range T_A

–25...71°C .................................................. -7

Customer specific ................................ -0...-6

Auxiliary functions and options

Remote bus voltage monitoring (option)..... D ¹

Cell voltage selector switch ......................... Z ²

Input fuse externally accessible................... F

Baseplate (option)......................................B1

¹See also: Description of Options as well as data sheet: Back Planes for the T Series.

²Only for T 1240/1740/1840

³No input for remote temperature sensor

⁴With input for remote temperature sensor

Example: LT 1740-7Z: AC-DC converter, input voltage range 85...255 V_rms, single output 50.5...56.5 V DC, 10 A, opera-

tional ambient temperature –25...71°C, with cell voltage selector switch.

Edition 4/4.99

MELCHER

2/33

The Power Partners.

Rugged Environment

AC-DC Converters >100Watt

T Series

Sensor Type Key

Type Key

S 48 - 2.23 - 30 - 02

Series ...............................................................................S ¹

Battery nominal voltage

24 V ........................................................... 24

36 V ........................................................... 36

48 V ........................................................... 48

Cell voltage (at 20°C)

2.23 V ..................................................... 2.23

2.27 V ..................................................... 2.27 ²

Temperature coefficient

–3.0 mV/K/cell ........................................... 30

–3.5 mV/K/cell ........................................... 35

–4.0 mV/K/cell ........................................... 40

–4.5 mV/K/cell ........................................... 45

other temperature coefficients on request .....

Cable length (2 m).......................................................... 02

¹Only for LT 1240/1740/1840

²For units without cell voltage selector switch

Edition 4/4.99

3/33

MELCHER

The Power Partners.

T Series

AC-DC Converters >100Watt

Rugged Environment

Functional Description

The T unit is a primary controlled AC-DC converter with a

constant switching frequency of 65.5 kHz. The power factor

corrected single step conversion of the line input voltage to

a low output voltage results in extremely high efficiency.

System Good and Output voltage OK are each indicated by

a green LED, inhibit and T System Failure by a red LED.

System Good and Power Down are available as open col-

lector signals at the connector. The threshold level of the

Power Down signal can be externally adjusted at the D set

input.

The input voltage is fed via input fuse, filter and rectifier to

the main transformer. The wideband input filter with small

input capacitance generates virtually no inrush current.

Transient suppressors protect the unit against high voltage

peaks and surges. An auxiliary converter generates an in-

ternal supply voltage for the primary control logic. The input

voltage waveform is sensed by the primary control logic to

allow power factor correction.

Test sockets at the front panel allow the measurement of

the output voltage.

The battery charger version provides additional features to

control the output voltage. To set it to different battery float

charge voltages, a 16-step selector switch (Z) is standard.

A control input for remote output voltage adjustment, by an

external temperature sensor is available at the multifunc-

tional inhibit/U_crcontrol pin. A trim-potentiometer allows fine

adjustment of the output voltage.

The main transformer is connected to a rectifier, large out-

put capacitors and an efficient output filter which ensures

low output ripple and spikes and provides the necessary

hold-up time. The output voltage is fed back to the primary

control logic via a signal transformer.

The inhibit signal and the T failure signal are transferred by

a second signal transformer (no opto-couplers!).

+

–

03043

C_y

12

Vo+

14

Fuse

4

6

P~

N~

16 Hot-plug +

NTC

18 Hot-plug –

20 Vo–

22 Vo–

C_y

Auxiliary

Converter

C_y

8

10

24

26

Sys In

Voltage

and

System

Monitor

Sys Out

Control

Circuit

28 i/Ucr

30

32

D

D set

Isolation 4 kV_rms

Z

P

Fig. 1

Block diagram

Edition 4/4.99

4/33

MELCHER

The Power Partners.

Rugged Environment

AC-DC Converters >100Watt

T Series

Electrical Input Data

General conditions:

– T_A= 20°C

Table 2a: Input Data LT types

Input

LT 12xx

LT 17xx

LT 18xx

Characteristic

Conditions

min

155

typ

max min

typ

max min

typ

max Unit

255 V_rms

U_i

Input voltage range

with full output power

AC

(47...63 Hz)

255

155

255

130

U_{i red}Input voltage range with

reduced output power ¹

85

155

85

155

85

130

U_{i nom}Nominal input voltage

I_{i nom}Nominal input current

230

1.9

3

230

2.6

4

230

2.2

4

U_{i nom}, P_{o nom}

A_rms

W

I_{i L}

Input current limit

P_{i 0}

No-load input power

U_{i min}...U_{i max}, I_o= 0

U_{i min}...U_{i max}, inhibit = low

U_{i nom}, I_{o nom}

6

8

P_{i inh}Input power when inhibited

3

PF

C_i

Power factor ²

96

98

%

µF

Input capacitance ³

Switch on delay

U_{i nom}

4

t_on

U_{i nom}, P_{o nom}

400

ms

u_{i RFI}Input RFI level ⁴

I_o= I_{o nom}

B

EN 55014, EN 55011/022

U_{i p}

U_{i L}

F

Input overvoltage protection ⁵

264

264 V_rms

Input undervoltage lock-out

Input fuse 5 × 20 mm

Switching frequency

75

V

A

6.3

f_tr

65.536

kHz

Table 2b: Input Data UT types

Input

UT 12xx

UT 17xx

Characteristic

Conditions

min

95

typ

max min

typ

max Unit

140 V_rms

U_i

Input voltage range

with full output power

AC

(47...63 Hz)

140

100

U_{i red}Input voltage range with

reduced output power ¹

70

95

70

100

U_{i nom}Nominal input voltage

I_{i nom}Nominal input current

115

3.8

5

115

5.2

6

U_{i nom}, P_{o nom}

A_rms

W

I_{i L}

Input current limit

P_{i 0}

No-load input power

U_{i min}...U_{i max}, I_o= 0

U_{i min}...U_{i max}, inhibit = low

U_{i nom}, I_{o nom}

6

8

P_{i inh}Input power when inhibited

3

PF

C_i

Power factor ²

98

%

Input capacitance ³

Switch on delay

U_{i nom}

4

µF

t_on

U_{i nom}, P_{o nom}

400

ms

u_{i RFI}Input RFI level ⁴

I_o= I_{o nom}

B

EN 55014, EN 55011/022

U_{i p}

U_{i L}

F

Input overvoltage protection ⁵

165

165 V_rms

Input undervoltage lock-out

Input fuse 5 × 20 mm

Switching frequency

65

V

A

10

f_tr

65.536

kHz

¹The output power is reduced because of the input current limitation P_o≈ U_i[V_rms] ¥ I_iL[A_rms] ¥ h

²Power factor as a function of the input voltage and load as well as harmonic distortion see Power Factor, Harmonics.

³Inrush current stays factor 10 below ETS 300132-1.

⁴150 kHz...30 MHz: CISPR 11/22/EN 55011/22 class B, 30...300 MHz: CISPR14/EN 55014

⁵In case of overvoltage the unit switches off temporarily, resulting in reduced output power and increased RFI.

Edition 4/4.99

MELCHER

5/33

The Power Partners.

T Series

AC-DC Converters >100Watt

Rugged Environment

Input Fuse

Efficiency

An input fuse (5 × 20 mm) fitted in the line (P) path mounted

inside the converter protects the module against severe

defects. (See also: Safety and Installation Instructions.) For

applications where the fuse should be accessible: see Op-

tion F.

The extremely high efficiency of the T series is achieved by

using a single step power factor corrected converter topo-

logy together with the most advanced technology in power

conversion.

It allows a very compact design in a fully enclosed case

without forced cooling.

Table 3: Fuse Type

Eff.

0.96

04024

Series

LT

Schurter type

Part number

0001.1012

0001.2514

SP F 6.3 A, 250 V

SPT 10 A, 250 V

0.94

0.92

0.90

0.88

0.86

0.84

0.82

UT

Inrush Current

The T units operate with 4 µF input capacitance resulting in

a low peak current of short duration when the unit is con-

nected to the mains. During switch on the input current can

rise up to the input current limit I_{i L}. As a direct result of the

low and short inrush current and controlled charging proce-

dure of the output capacitors, the unit can be hot plugged to

the mains causing only negligible disturbances. The LT in-

rush current is a factor 10 smaller than defined in the ETS

300 132-1 standard for Telecom Systems. However the unit

should be plugged-in smoothly giving time to the output ca-

pacitors to be charged.

I_o[A]

0.80

0

2

4

6

8

10

12

14

16

U_i= 110 V

U_i= 230 V

rms

Fig. 3

Efficiency versus load of LT 1701

Input Under-/Overvoltage Lock-Out

If the specified input voltage range U_iis exceeded, the unit

stops operation temporarily resulting in reduced output

power and increased RFI. The input is protected by

varistors. Continuous overvoltage will destroy the unit.

04026

I_i[mA/W]

3.5

3.0

2.5

2.0

If the sinusoidal input voltage stays below the input under-

voltage lock-out threshold U_i, the unit will be inhibited.

Power Factor, Harmonics

Limit class D according

to IEC/EN 61000-3-2

Power factor correction is achieved by controlling the input

current waveform synchronously with the input voltage

waveform. The power factor control is active in all operating

conditions (voltage regulation, output power limitation, cur-

rent limitation). The power factor control also works with dif-

ferent input voltage waveforms and frequencies. Operation

at frequencies above 60 Hz will result in higher leakage cur-

rents. For special applications with different frequencies or

non-sinusoidal wave forms, please contact Melcher.

1.5

1.0

0.5

Harm.

0

3

5

7

9

11

13 15

17 19

Fig. 4

Harmonic distortion at input LT 1740-7Z, U_i= U_inom

I_o= I_{o nom}

,

PF

04023

1.00

0.98

0.96

0.94

0.92

0.90

0.88

0.86

0.84

0.82

I [mA/W]

3.5

04025

i

3.0

Limit class D according

to IEC/EN 61000-3-2

2.5

2.0

1.5

1.0

0.5

0

I_o[A]

0.80

0

2

4

6

8

10

12

14

16

Harm.

3

5

7

9

11

13 15

17 19

UT 1740-7Z at U_i= 110 V_rms

LT 1740-7Z at U_i= 230 V_rms

Fig. 5

Harmonic distortion at input UT 1740-7Z, U_i= U_inom

I_o= I_{o nom}

,

Fig. 2

Power factor

Edition 4/4.99

6/33

MELCHER

The Power Partners.

Rugged Environment

AC-DC Converters >100Watt

T Series

Electrical Output Data of the Rectifier Version

General conditions:

– T_A= 20°C, unless T_Cis specified.

– U_i= U_{i nom}, f = 50 Hz

Table 4: Output data

Output

LT/UT 1201

LT/UT 1701

LT 1702

Characteristic

Conditions

min typ max min typ max min typ max Unit

U_{o set}

Output voltage adjustment

U_{i nom}

24.25

54.5

48.0

V

I_o= 0.5 • I_{o nom}

U_{o set tol}U_osetting tolerance

24.0

24.5 54.25

24.95 52.8

54.75 47.75

55.8 46.3

48.25

49.3

U_o

Output voltage over input voltage and¹load U_{i min}...U_{i max}

23.35

(See fig.: Typical output voltage verus

input voltage and output current.)

I_o= 0.01•I_{o nom}

...I_{o nom}

U_{o L}

Output Overvoltage protection by

electronic inhibit

32.5

59.3

a_Uo

I_{o nom}

I_{o L}

Temperature coefficient of output voltage

Nominal output current

Current limit ²

T_Cfixed value

–5

16

–5

10

–5

11

mV/K

A

U_o= 20 V

U_{i nom}

18 ⁴

400

14.5

550

14.5

550

P_{o L}

u_o

Output power limit ²

W

V_pp

mV_pp

V_pp

V

Output voltage noise

Low frequency

Switching freq.

Total

I_{o nom}

IEC/EN 61204 ⁵

BW = 20 MHz

0.85

1.0

1.05

40

0.9

0.6

1.05

1.2

1.1

1.2

DU_{o I}

Static load regulation ¹(See fig.: Typical

output voltage versus input voltage and

output current.)

I_o= 0.01•I_{o nom}

...I_{o nom}

DU_{o U}Static line regulation (See: Typical output

voltage versus input voltage and output

current.)

U_i=U_{i min}...U_{i max}

I_{o nom}

0.3

0.8

u_{o d}

t _d

Dynamic load regulation ³Voltage deviation U_{I nom}

1.7

2.2

(See fig.: Dynamic cha-

racteristic under varying

load conditions.)

I

_{o nom}↔ ¹/10 I_{o nom}

Recovery time

0.25

s

IEC/EN 61204 ⁶

C_o

Internal output capacitance

86

41

mF

¹Output voltage decreases with rising output current because of output voltage slope for automatic current sharing capability.

²Due to the large output capacitors the maximum transient value can be much higher.

³Deviation limited by output overvoltage protection.

⁴No power limitation, but current limitation.

⁵See: Technical Information: Measuring and Testing.

⁶See fig.: Dynamic load regulation.

Output Characteristics (Recifier Version)

Output

voltage

Output

power

Output

current

The T 1701/1702 types can be operated in 3 different

modes:

U_o[V]

60

regulation limitation limitation

– Output voltage regulation

– Output power limitation

– Output current limitation

50

40

30

– In output voltage regulation mode the T unit can be oper-

ated within the full temperature range –25...71°C.

– In output power or current limitation mode the max. ambi-

ent temperature T_Ashould not exceed 65°C with free air

convection cooling.

20

10

0

Fig. 6

I_o[A]

0

2

4

6

8

10

12

14

16

Output characteristics LT 1701-7

U_i= 110 V_rms

U_i= 230 V_rms

Edition 4/4.99

7/33

MELCHER

The Power Partners.

T Series

AC-DC Converters >100Watt

Rugged Environment

Output voltage regulation (Rectifier Version)

Output current limitation (Rectifier Version)

The output voltage of rectifier models is adjusted to a fixed

value U_{o set}. It relates to the output current and the input

voltage which ensures automatic current sharing operation

without further precautions when several units are con-

nected in parallel. Rising output current and falling input

voltage lead to a decrease of the output voltage, according

to the formula:

The output of the T units is fully protected against continu-

ous short circuit. The maximum constant current is limitted

to I_{o L}(see table: Electrical output data). As the LEDs indi-

cating the system status are driven from the output voltage,

in short circuit mode all LEDs switch off.

04027

U_o[V]

54.5

48

U_o≈ U_{o set tol}+ (0.5 – I_o/I_onom) • DU_{o l}+ (U_i- U_{i nom})/100 V •

DU_{o U}

∆U_o

05081

38

2%

1%

U_{o set}

0

I_o[A]

0

–1%

–2%

10 11

14.5

Load

regulation

Fig. 8

Typical output voltage versus output current of UT/LT 1701/

1702

I_o/I_{o nom}

0.01

0.5

1

U_o[V]

Fig. 7

Typical output voltage versus input voltage and output

current of LT 1701

05048

24

Note: Units with different output voltage regulation charac-

teristics (e.g. less output current dependency) are available

upon request.

I_o[A]

0

Output power limitation (Rectifier Version)

16

Especially for power systems with an output voltage of 48V

and more, the rectifier models T 1701/1702 feature an out-

put power limitation mode. The output power is kept con-

stant down to an output voltage of approximately 38 V. This

provides improved start-up capabilities of power systems

including switched mode power supplies connected to the

DC bus (e.g. Melcher CQ units). At maximum load there is

no need for a special start-up procedure.

Fig. 9

Typical output voltage versus output current of UT/LT 1201

Hold-up Time (Rectifier Version)

The hold-up time depends upon the output voltage at the

time of failure, the minimum acceptable output voltage and

the load according to the following formula:

2

U_o²– U_o

min u

The maximum input current is limited to I _{i L}. At lower input

voltage U_{i red}the maximum output power is limited to:

t_hold= –––––––––––– • (C_o+ C_ext

)

2 • P_o

P_o≈ h • U_{i red}• I_{i L}

(h = efficiency ≈ 90%)

The T 1201 types have no output power limitation charac-

teristic.

where:

U_o

U_{o min u}= Minimum acceptable output voltage

= Output voltage at the moment of mains failure

P_o

= Average output power during hold up time

= Internal output capacitance

C_o

C_ext

= External output capacitance (e.g. on backplane)

Output Overvoltage Protection (Rectifier Version)

Examples of t _holdare given in the table below:

A slight output voltage overshoot may occur at turn on, in-

hibit release or during fast load changes. A second, inde-

pendent control loop interrupts operation above U_{o L}indi-

cated by the red LED. The output voltage remains below

60 V (SELV) under all operating conditions.

Table 5: Hold-up time t_holdfor T1701

U_o= 54 V

P_o[W]

U_{o min u}

Unit

Note: There is no specific built-in protection against exter-

nally applied overvoltages or transient sources like e.g.

motors. Never apply voltages >60 V (>35 V) to the output.

Otherwise the unit may be damaged.

46 V

43 V

40 V

38 V

100

200

300

400

500

550

164

82

55

41

33

30

219

109

73

55

44

270

135

90

67

54

302

151

101

75

60

55

ms

40

49

Edition 4/4.99

8/33

MELCHER

The Power Partners.

Rugged Environment

AC-DC Converters >100Watt

T Series

U

U_o

05051

mains failure

05049

DU_{o I}

10% DU_{o d}

U_o

U_t

low load

U_o

DU_od

heavy load

U_{o min u}

t_d

t

I_o/I_{o nom}

warning time

1

0.9

t_hold

0.1

Fig. 10

Hold up and warning time with power down output signal.

Fig. 12

The table: Hold up time also gives information about the

warning time of the power down signal. If for example the

threshold level U_tof the power down signal is set to 43 V

and the minimum acceptable voltage of the load is 38 V the

time between the activation of the power down signal and

the switch-off of the load (550 W) will be 15 ms (55 ms -

40 ms).

Dynamic characteristics under varying load conditions

(see: Electrical Output Data)

Inhibit input (Rectifier Version)

The rectifier versions are equipped with the inhibit function

only. (The Ucr remote control is used with the battery char-

ger version.)

Pulse Loading (Rectifier Version)

The unit is enabled by a logic high signal and disabled by a

logic low signal. This input is TTL/CMOS compatible, a re-

sistor <50 Ω disables the unit, a resistor >30 kΩ enables it.

The switch-on time t_rof the unit, i.e. the time delay between

powering until the full output power is available, is typically

100 ms.

To prevent an overload of the output and filter capacitors

the superimposed AC ripple current at the output should be

limited as shown below. For high current pulse loads exter-

nal capacitors are recommended.

For other pulse loads than stated in the figure below, e.g.

The hold up time at the output after inhibiting depends on

the load, the internal capacitance of the unit and additional

capacitance on the DC bus.

U_i< U_{i nom}, I_o> I_{o nom}, please contact Melcher.

I_{o PL}[A_rms

]

05050

The inhibit input is protected against DC overvoltage up to

60 V.

15

U_i= U_{i nom}

Average output current = I_{o nom}

06116

4

12

28

P~

Vo+

i/Ucr

10

5

I_inh

U_inh

T_C= 50°C

T1000

T_C= T_{C max}

N~

6

22

Vo–

0

f

_PL[Hz]

100

1 k

10 k

50

Fig. 13

Inhibit signal connection

Fig. 11

Maximum allowable AC ripple output current superim-

posed on the average output current I_{o nom}with LT 1701

unit.

Table 6: Characteristics of the inhibit signal

Characteristics

Conditions min typ max Unit

U_inhInhibit

voltage

U_o= on U_{i min}...U_{i max}2.5

T_{C min}...T_{C max}

60

V

kΩ

V

R_inhResistance U_o= on

30

to Vo–

U_inhInhibit

voltage

U_o= off

-0.7

0.4

50

R_inhResistance U_o= off

Ω

t_r

Switch-on time

until full power avail.

U_{i nom}

100

3

ms

P_inhInput power with

inhibited unit

W

Edition 4/4.99

9/33

MELCHER

The Power Partners.

T Series

AC-DC Converters >100Watt

Rugged Environment

Electrical Output Data of Battery Charger Version

General conditions:

– T_A= 20°C, unless T_Cis specified.

– U_i= U_{i nom}, f = 50 Hz

Table 7: Output data

Output

LT/UT 1240

LT/UT 1740

LT 1840

Characteristic

Conditions

min typ max min typ max min typ max Unit

U_{o set}

Output voltage adjustment ¹

U_{i nom}

27.25

54.5

40.88

V

I_o= 0.5 • I_{o nom}

U_{o set tol}U_osetting tolerance ¹

U_{o range}Output voltage range ²

27.2

25.25

26.8

27.3 54.45

28.25 50.5

27.6 53.8

27.65 54.0

54.55 40.83

56.5 37.9

55.0 40.3

55.1

40.93

42.4

41.3

U_o

Output voltage over input voltage

LT U_{i min}...U_{i max}

and load ^{3, 1}(See fig.: Typical output

voltage versus input voltage and

output current.)

I_o= 0.01•I_{o nom}

UT

26.9

...I_{o nom}

U_{o L}

Output overvoltage protection by

electronic inhibit

32.5

59.3

48.4

a_Uo

I_{o nom}

I_{o L}

Temperature coefficient of output voltage T_Cfixed value

Nominal output current

–3

14.5

20

–3

10

–3

11

mV/K

A

Current limit ⁵

14.5

550

16

P_{o L}

u_o

Output power limit ⁵

Output voltage noise

U_{i nom}

400

450

W

Low frequency

Switching freq.

Total

I_{o nom}

IEC/EN 61204 ⁷

BW = 20 MHz

0.71

1.0

0.85 V_pp

mV_pp

40

0.75

0.4

1.05

0.6

0.9

0.6

V_pp

V

DU_{o I}

Static load regulation ³(See fig.: Typical

output voltage versus input voltage and

output current.)

I_o= 0.01•I_{o nom}

...I_{o nom}

DU_{o U}

Static line regulation (See fig.: Typical

output voltage versus input voltage and

output current.)

U_i=U_{i min}...U_{i max}

I_{o nom}

0.2

0.35

0.25

u_{o d}

t _d

Dynamic load regulation⁶Voltage

(See fig.: Dynamic charac- deviation

U_{I nom}

1.6

0.2

2.0

0.2

2.5

0.2

I

_{o nom}↔ 10%

8

teristics under varying

I_{o nom}

Recovery time

s

load conditions without

battery back-up.)

IEC/EN 61204

C₀

Internal output capacitance

86

41

49

mF

¹Output voltage adjustment with U_cr= 9.5 V (2.27 V/cell).

²Defined by sensor, by remote control and by voltage selector switch.

³Output voltage decreases with rising output current because of output voltage slope for automatic current sharing capability.

⁵Due to the large output capacitors the maximum transient output current can be much higher than I_{o L}, P_{o L}, respectively.

⁶Without battery backup.

⁷See: Technical Information: Measuring and testing.

⁸See fig.: Dynamic load regulation. Load current change for specified output. Other outputs loaded with I_{o nom}

.

Edition 4/4.99

MELCHER

10/33

The Power Partners.

Rugged Environment

AC-DC Converters >100Watt

T Series

∆U_o

Output Characteristics (Battery Charger Version)

05046

The battery charger versions T 1240/T 1740/T 1840 series

can be operated in 3 different modes:

– Output voltage regulation

– Output power limitation

– Output current limitation

1.1%

0.55%

U_{o set}

0

Output

voltage

Output

power

Output

current

Load

regulation

–0.9%

U_o[V]

60

regulation limitation limitation

I_o/I_{o nom}

0.01

0.5

1

50

40

30

Fig. 15

Typical output voltage versus input voltage and output

current of the LT 1740.

Output power limitation (Battery Charger Version)

All battery charger versions feature an output power limita-

tion mode where the output power is kept constant from

2.35 V/cell (for lead acid batteries) to 1.6 V/cell. This pro-

vides better starting up capabilities for power systems in-

cluding switched mode power supplies connected to the

DC bus when the battery is charged.

20

10

0

I_o[A]

0

2

4

6

8

10

12

14

16

The maximum input current is limited to I_{i L}. At lower input

voltage U_{i red}, the maximum output power is limited to:

U_i= 110 V_rms

U_i= 230 V_rms

Fig. 14

Output characteristics LT 1740-7

P_o≈ h • U_{i red}• I_{i L}(h = efficiency ≈ 90%)

Typical output characteristics according to type

– In output voltage regulation mode the T unit can be oper-

ated within the full temperature range –25...71°C.

06065

U_o

28.25 V

– In output power or current limitation mode the max. ambi-

ent temperature T_Ashould not exceed 65°C with free air

convection cooling.

26.7 V

25.25 V

19 V

Output current limitation (Battery Charger Version)

The output of the T units is fully protected against continu-

ous short circuit. The maximum constant current is limitted

to I_{o L}(see table: Electrical output data). As the LED indicat-

ing the system status are driven from the output voltage, in

short circuit all LED‘s will switch off.

I_o

0

15 A

20 A

Fig. 16

Typical output voltage versus output current of UT/LT 1240

06066

U_o

56.5 V

Output voltage regulation (Battery Charger Version)

54.5 V

50.5 V

In normal operating mode (unit neither in power limitation

nor in current limitation) the output is regulated by a voltage

feedback loop. It is adjustet to U_{o set}and can be set by the

cell voltage selector switch to the appropriate float charge

voltage of the battery.

38 V

I_o

The battery charger version features a control input (pin 28)

for remote output voltage adjustment either by a voltage

source, a temperature sensor or an external potential di-

vider (see: Output voltage control via Inhibit/Ucr remote

control input). For fine tuning, the units are fitted with a trim

potentiometer accessible from the rear of the connector.

0

10 A

14.5 A

Fig. 17

Typical output voltage versus output current of UT/LT 1740

06067

U_o

42.4 V

40.88 V

37.9 V

The output voltage relates to the output current and the in-

put voltage which ensures automatic current sharing opera-

tion without further precautions when several units are con-

nected in parallel. An increase in output current and a de-

crease in input voltage decreases the output voltage, ac-

cording to the formula: U_o≈ U_{o set tol}+ (0.5 – I_o/I_{o nom}) • DU_{o I}

+ (U_i– U_{i nom})/100 V • DU_{o U}

28.5 V

I_o

0

11 A

16 A

Fig. 18

Note: Units with different output voltage regulation e.g.

less output current dependency are available upon request.

Typical output voltage versus output current of LT 1840

Edition 4/4.99

11/33

MELCHER

The Power Partners.

T Series

AC-DC Converters >100Watt

Rugged Environment

Output Overvoltage Protection (Battery Charger

Version)

Dynamic output characteristic

U_o

05051

A slight output voltage overshoot may occur at turn on, in-

hibit release or during fast load changes. A second inde-

pendent control loop interrupts operation above U_{o L}, indi-

cated by the red LED. The output voltage remains below

60 V (SELV) under all operating conditions.

DU_{o I}

U_o

10% DU_{o d}

DU_od

Note: There is no specific built-in protection against ex-

ternally applied overvoltages or transient sources like

e.g. motors. Never apply voltages exceeding U_{o L}to the

output. Otherwise the unit may be damaged.

t_d

t

I_o/I_{o nom}

1

0.9

0.1

Fig. 19

Dynamic characteristics under varying load conditions

(see Electrical output data) without battery back-up.

Control Features of the Battery Charger Version

According to the recommendations of battery manufactur-

ers, the float charge voltage of a lead acid battery should be

temperature compensated. Depending upon the battery

type and size, charging with different temperature coeffi-

cients may be required. An excessive float charge voltage

may damage the battery through overcharging.

Cell voltage selector switch Z

The standard units T xx40-7Z are equipped with the cell

voltage selector switch at the rear side of the unit, which

provides an easy way of external adjustment to the recom-

mended float charge voltage for specific battery types.

Each switch position allows a step in the output voltage of

10 mV/cell whereby the switch position "0" represents a cell

voltage of 2.23 V at 20°C and the switch position "C" gives

2.35 V per cell.

Most lead acid battery manufacturers recommend cell volt-

ages between 2.23 V and 2.32 V with the nominal cell volt-

age defined at 20°C and temperature coefficients between

–3 and –4 mV/K/cell.

The cell voltage selector switch fits together with the

Melcher 2.23 V temperature sensor. The float charge volt-

age is set by the switch and the temperature coefficient is

specified by the sensor type.

The value of the negative temperature coefficient, is speci-

fied by the temperature sensor.

With the cell voltage selector switch Z the required cell volt-

age can be adjusted at the rear of the unit, making the sys-

tem flexible to different float charge voltages of battery sys-

tems.

06068

2.23 V

2.24 V

2.25 V

0

Where the selector switch Z is not applicable, a cell voltage

adjustment can also be provided via the temperature sen-

sor (see: Temperature Sensor).

2.26 V

2.27 V

2.28 V

4

2.35 V

C

Although it is not recommended, the output voltage can be

set to a fixed value without temperature compensation by

an external voltage source or a resistive voltage divider at

the remote control input (e.g. if the battery temperature

shall be controlled by other systems, see: Output voltage

control via Inhibit/Ucr remote control input).

8

2.29 V

2.30 V

2.32 V

2.31 V

Fig. 20

Cell voltage selector switch

What needs to be considered with all battery charger types:

The final float charge voltage is only reached with a fully

loaded battery. Since new batteries directly supplied from

the manufacturer are only charged to 70...80% of their ca-

pacity, the battery system should be operated for min. 72 h

prior to checking the float charge voltage.

Important: Setting the switch to the correct battery cell

voltage is vital for the proper operation of a battery sys-

tem. Check whether the switch position corresponds to

the required battery cell voltage prior to putting a system

into operation.

Note: Switching to a different cell voltage while the T unit is

in operation may cause a small and short distortion of the

output voltage.

Edition 4/4.99

12/33

MELCHER

The Power Partners.

Rugged Environment

AC-DC Converters >100Watt

T Series

Potentiometer for fine tuning

T units are fitted with a one-turn potentiometer for fine tun-

ing of the output voltage to within ±3.7⁰/00 of U_o. The

potentiometer is protected by a plastic cover. To adjust the

output voltage for improved current sharing or compensa-

tion for voltage drops over the load lines, each of the T units

in a system should be unplugged and adjusted individually

to the same output voltage at equal load; otherwise current

sharing may adversely be affected.

Output voltage control via Inhibit/Ucr remote control input.

Table 8: Characteristics of the inhibit signal

Characteristics

Conditions

min

2.5

typ

max

60

Unit

V

U_inh

R_inh

U_inh

R_inh

t_r

Inhibit voltage

U_o= on

U_o= off

U_{i min}...U_{i max}

T_{C min}...T_{C max}

Resistance to Vo-

Inhibit voltage

30 k

– 0.7

Ω

0.4

50

V

Resistance to Vo-

Ω

Switch on time until full power available

Input power at inhibited unit

U_inom

100

3

ms

W

P_inh

T 1240

T 1740

The Inhibit/Ucr remote control input at connector pin 28 pro-

vides two functions:

T 1840

U_o[V]

06069

56.5

28.25 42.37

– External adjustment of the output voltage

– Inhibiting of the unit

55

54

53

52

A voltage <0.4 V inhibits the output, a voltage >2.5 V ena-

bles it.

41

27

By the Ucr remote control input range of 5.5 V < U cr

< 11.5 V, the output voltage U_{o set}can be adjusted within a

range of +3.6% to –7.9%. This feature is optimized to con-

trol the float charge of lead acid batteries.

39

26

Outside of the control range, the sensor monitoring circuit

generates a system error signal (see also: System Good).

50.5

25.25 37.85

In the case of a excessively high control voltage, the output

is reduced.

14

U

16

4

5 5.5

_cr[V]

3

11.5

The remote control input is protected against DC overvolt-

age up to 60 V .

Signal high

Logic level of

System

Good

Signal low

5.3 V

signal

U_cr[V]

14 V

Fig. 21

Output voltage U_oversus control voltage U_cr, with corre-

sponding system good signal level

Table 9: Characteristics of the remote control

Characteristics

Conditions

LT/UT 1240

LT 1840

typ

LT/UT 1740

Unit

V

typ

U_o

Output voltage at:

Voltage selector

switch Z set at

2.23 V/cell or without

selector switch

U_{i nom}

25.25

37.85

50.5

U_crfail 2.5...5.5 V

U_crcontrol 5.5...11.5 V

U_crclamp 11.5...14 V

U_crfail 14...60 V

22.5 + U_cr• 0.5 33.75 + U_cr• 0.75

45 + U_cr

56.5

50.5

1

28.25

25.25

1

42.37

37.85

1

0.5 • I_{o nom}

R_cr

f_cr

Input impedance

Frequency limit

MΩ

1

Hz

Note: An open inhibit/Ucr remote control input leads to a

sensor error signal which is indicated by the Error LED at

the front and high impedance of the "System good" signal.

The output voltage is reduced to U_crfail condition.

The inhibit input of the T xx40-7Z is not TTL/CMOS compat-

ible and should be triggered by a switch, a relay or an open

collector transistor.

If the voltage selector switch Z is not set at 2.23 V per cell,

the U_crfail voltage rises accordingly.

Edition 4/4.99

13/33

MELCHER

The Power Partners.

T Series

AC-DC Converters >100Watt

Rugged Environment

Remote control by a resistive potential divider

Remote control by an external voltage source.

With a resistive potential divider or a potentiometer con-

nected to the remote control input, a fixed output voltage

can be programmed:

05062

28

22

i/Ucr

+

Ext. voltage

source

5.5...11.5 V

U_cr

05063

U_o+

12

Vo+

–

Vo–

R₁

R

i/Ucr

28

Fig. 23

Voltage setting by an external voltage source

U_cr

22

R₂= 1 MΩ • R/(1 MΩ + R)

U_o–

1 MΩ

Vo–

Remote control by a temperature sensor

05064

Fig. 22

Voltage setting by a resistive potential divider

–

+

Sensor Sensor Temperature

wires

cable

sensor

U_cr= U_o– 45 V

U_cr= (U_o– 33.75 V) • ⁴/

(LT/UT 1740)

(LT 1840)

28

12

22

i/Ucr

Vo+

Vo–

3

U_cr= 2 • U_o– 45 V

(LT/UT 1240)

–

+

U_o• R₂

U_cr= ––––––––

(R₁+ R₂)

Battery

R₂: Value with 1 MΩ internal resistance in parallel with R.

It is mandatory that:

Fig. 24

Voltage setting by a temperature sensor, wiring diagram

(R₁• R₂)

(R₁+ R₂)

––––––– >35 kΩ

The Melcher temperature sensor provides a temperature

compensated charging process for lead acid batteries, see

also: Temperature Sensors.

otherwise the unit might not be able to start.

Edition 4/4.99

14/33

MELCHER

The Power Partners.

Rugged Environment

AC-DC Converters >100Watt

T Series

Temperature Sensors

05065

The active T temperature sensors are of robust construc-

tion, mounted into a sealed aluminium tube of 12 mm outer

diameter and 50 mm length. The sensors are water proof

(IP 66) and high voltage tested with 1.4 kV DC. Connection

should be done via the colored 3-wire cable to the T unit

output (Vo+ and Vo-) and the remote control input U_cr.

Wrong connection may damage the sensor.

brown

white

green

12/14

Vo+

28

i/Ucr

Sensor

20/22

Vo–

Fig. 25

Wiring diagram sensor

The temperature sensor should be as close to the battery

terminal as possible for most accurate temperature meas-

urements.

Table 10: Type survey

Sensor types

Battery voltage

Float charge

Cell voltage

Temp. coefficient

Cable length

nominal [V]

voltage (20°C) [V]

(20°C) [V/cell]

[mV/K/cell]

[m]

1

2

S24-2.23-30-02

S24-2.23-35-02

S36-2.23-30-02

S36-2.23-35-02

S48-2.23-30-02

S48-2.23-35-02

S48-2.27-30-02

S48-2.27-35-02

24

36

48

26.76

2.23

–3.0

–3.5

–3.0

–3.5

–3.0

–3.5

–3.0

–3.5

2

26.76

2.23

40.14

2.23

40.14

2.23

53.52

2.23

53.52

2.23

54.48

2.27

54.48

2.27

¹Standard types for conventional tubular lead acid batteries. The same sensor can be used for battery systems with different cell volt-

ages within the selectable range of Z. Each step on the selector switch changes the cell voltage by 10 mV in the range from 2.23 V up

to 2.32 V, at 20°C.

²Standard types for sealed lead acid batteries for LT 1740 without option Z.

Battery specific sensors with cell voltages from 2.23 V up to

2.32 V and temperature coefficients from –2 up to –4.5 mV/

K/cell or different cable lengths are available upon request.

Since battery life is halved with every 10 K temperature in-

crease, it is recommended that the batteries be mounted at

the bottom of the cabinet or in a separate, cool area.

Note 3:

Important remarks

The sensor supply wire Vo+ (brown) should be refered to

the T unit output pin 12/14. If the sensor common (green)

wire is connected to the power bus, resistive voltage drops

or voltage drops across decoupling diodes in the Vo– sup-

ply line will be compensated by the sensor.

Note 1:

By choosing a battery with a large temperature coefficient

or with a high cell voltage, the required temperature range

may be limited by the output voltage control range of the T

unit(s).

Decoupling diodes or fuses in the Vo– supply line are not

recommended as in case of a short circuit across the output

of a T unit, status signalling of the system is affected.

Note 2:

The temperature sensor together with the mounting fixture

should be mounted as close as possible to the battery.

Through their chemical activity batteries may be warmer

than the ambient temperature. Battery banks heat up if they

are mounted too close together thus blocking free air flow.

Note 4:

For installation of batteries see also VDE 510 as well as the

recommendations of the battery manufacturers.

Table 11: Sensor data

Characteristics

T_sensorSensor temperature range

U_cr

Condition

min

–10

3.9

typ

max

60

Unit

°C

V

U_cr= 5.5...11.5 V

Absolute ratings

T_sensor= 20°C

T_sensor= 0...53°C

Control voltage range

15

U_{cr td}

Control voltage tolerance

±0.1

±0.2

Edition 4/4.99

15/33

MELCHER

The Power Partners.

T Series

AC-DC Converters >100Watt

Rugged Environment

Functional Features

Available Signals and Status Monitoring

With option D the output voltage can be sensed externally

for example to monitor the system bus decoupled from the

power supplies by diodes or fuses.

The T series feature an inhibit function as well as several

voltage monitoring and indicating functions for easy control

and surveillance of a complete custom specific power sup-

ply system. All the surveillance functions are driven from

the T output potential and also operate in case of a mains

failure down to an output voltage of 5 V. The power con-

sumption of the surveillance circuit is typically 10 mA to

20 mA.

With option D a resistor of 43.2 kΩ 1% (21.5 kΩ for T 1840)

should be fitted externally into the sense line to the bus (see

fig.: With option D; Power down signal monitoring...).

06050

+

–

12

Vo+

Available functions:

– Power Down

D

D set

Sys In

Sys Out pin 26

i/Ucr pin 28

pin 30

pin 32

pin 24

Vo– 22

– System Good

43.2 kΩ

(21.5 kΩ)

R

External adjustment

of the threshold

level U_t

R_ext

32

– Inhibit/Ucr remote control

(see Chapters: Rectifier respectively: Battery Charger)

D set

T 1000-7

Optical status monitoring is indicated by 3 LEDs on the front

panel:

Fig. 26

Standard version; Power down signal monitoring directly

the output of the T unit.

– System

– U_o

(OK)

green

red

06051

– Error

+

–

F

Test sockets at the front panel allow easy measurement of

the output voltage.

Vo+

12

Power Down

Vo–

22

The power down circuitry monitors the output voltage and

changes its output signal status from low to high impedance

when the output voltage falls below the low threshold level

and changes back to low impedance, when the output volt-

age exceeds the upper threshold level. The rectifier ver-

sions have a relatively small hysteresis of 1 V, the battery

charger versions have a large hysteresis. The upper

threshold level is given the low threshold level is externally

adjustable at the D set pin 32. Power Down can for example

be used as a save data signal, for low voltage warning, as a

low battery signal to avoid deep discharge of the battery

during long term mains failure or to prevent connected con-

verters from starting-up at a low bus voltage. For applica-

tion examples see figures below for power down use.

External adjustment of

R

43k2

R

ext

the threshold level U

t

D set 32

(21k5)

T 1000-7D

Fig. 27

With Option D; Power down signal monitoring the power

bus decoupled by a fuse.

Lower threshold level

With the resistor (R_ext) connected to D set input pin 32 and

Vo- (or Vo+) the low threshold level can be increased (or

decreased) respectively. (See fig. above)

If the D set input is left open the low threshold level of the

power down signal is factory set to:

As it is driven from the output, power down operates inde-

pendently of the input voltage and load conditions, even if

the unit is inhibited.

T 12xx:

T 17xx:

T 18xx:

U_{t set}= 21.0 V

U_{t set}= 42.5 V

U_{t set}= 32.0 V

±0.4 V

±0.5 V

±0.4 V

The standard version monitors the output voltage internally

(see fig.: Standard version; Power down signal monitoring

directly the output of the T unit).

The approximate resistor values for given threshold levels

can be calculated from the following formulae; (U_tin V):

Table 12: Calculation of R_ext

Types

U_t> U_{t set}

U_t< U_{t set}

(R_ext.connected to Vo–)

(R_ext.connected to Vo+)

T 12xx

463.5

R_ext(U_t) = –––––––– [kΩ]

U_t–21.0

43.2 U_t– 463.5

R_ext(U_t) = ––––––––––––– [kΩ]

21.0 – U_t

T 17xx

T 18xx

933

R_ext(U_t) = –––––––– [kΩ]

U_t– 42.5

43.2 U_t– 933

R_ext(U_t) = ––––––––––––– [kΩ]

42.5 – U_t

461

R_ext(U_t) = –––––––– [kΩ]

U_t– 32.0

21.4 U_t– 461

R_ext(U_t) = ––––––––––––– [kΩ]

32.0 – U_t

Edition 4/4.99

16/33

MELCHER

The Power Partners.

Rugged Environment

AC-DC Converters >100Watt

T Series

The threshold level is adjusted to a DC output voltage.

When in operation a sinusoidal low frequency output ripple

is superimposed on the DC output voltage. It can be esti-

mated with U_ov= I_o/(2 • π • f • C_o) where C_ois the internal

capacitance of the output of the unit.

Power down output signal characteristics

The power down output D is an open collector transistor

referenced to Vo–, protected by a 62 V Zener diode, and is

well suited to driving an external relay.

Under normal operating conditions (U_o> U_t) the power

down output D has low impedance. If the output voltage

drops below the power down threshold level, the signal out-

put becomes high impedance.

Table 13: Resistor values (R_ext) for given Power Down

threshold value U_tfor LT 1740 (typical values)

Characteristics

U_tPower Down

Conditions

U_t

Unit

Table 14: Characteristics of Power Down functions

69 kΩ to Vo+

34.4

36.4

39.5

42.5

45.5

48.5

51.6

V

threshold level set by 106 kΩ to Vo+

R_ext

Characteristics

Conditions

min typ max

Unit

254 kΩ to Vo+

left open

309 kΩ to Vo–

154 kΩ to Vo–

102 kΩ to Vo–

I_D

Output

T_{C min}...T_{C max}

50 ¹

mA

sink current

U_satU saturation

U_zZener voltage

P_zZ-diode P_LOSS

I_D= 50 mA

0.2

62

V

T_C= 95 °C

500

mW

Upper threshold level

¹To be limited to 50 mA by the external circuitry.

The upper threshold level of the Power down function is

given.

06053

The rectifier units T xx01/02 have a relatively small hyster-

esis of 1 V to prevent oscillation of the signal.

Vo+

12

D

30

The battery charger units T xx40 have a large hysteresis.

The upper level is set at 2.05 V/cell.

Vo–

To avoid deep discharge of the battery which would de-

crease the life expectancy, its load should be disconnected

from the battery at the low level of the Power down signal.

The battery voltage will then recover slowly up to its chemi-

cal equilibrium, about 2 V/cell. The load may not be con-

nected again to the battery until the T unit is operating and

charging it. Then the output voltage will be higher than

2.05 V/cell

22

R

ext

D set

32

T 1000

Fig. 29

Power Down

– External adjustment of threshold level U_t

– Signal electrically isolated by an external relay

High level of Power down signal

T 1240:

T 1740:

T 1840:

24.6 V

49.2 V

36.9 V

±0.3 V

±0.5 V

±0.4 V

06054

12

30

Vo+

D

U _Bat

R

06052

U _float

Battery

recovery

red LED

Load switch ON

Vo– 22

2.05 V/cell

2.0 V/cell

LED is "ON"

in case of

power down

T 1000

Hysteresis

Power Down

Fig. 30

U _t

Load switch OFF

Battery

low

Remote indication of Power Down by LED

t

06055

Mains failure

Return of mains

+5 V

12

30

Vo+

D

Z

Power down signal

high

R

t

low

Fig. 28

Hysteresis of power down signal for battery charger types

with corresponding level of power down signal

CMOS, TTL

Vo– 22

T 1000

Fig. 31

Remote indication of the output voltage status by CMOS/

TTL interface for e.g. Save Data

Edition 4/4.99

17/33

MELCHER

The Power Partners.

T Series

AC-DC Converters >100Watt

Rugged Environment

06056

connecting the output of the system good signal of one unit

to the input of the next unit. Low voltage (impedance) of the

input and output has the meaning of "System good". The

first input of the system has to be connected to Vo–.

Vo+

12

Vi+

10 kΩ

0.5 W

D

30

22

The signal "System good" is activated (low impedance) if

the following conditions are met:

i

Vo–

No external fault

– The Sys input signal is logic low

Gi–

PSK/PSR

T 1000

AND

Fig. 32

No faults monitored by the T unit such as:

– Input overvoltage

– Input undervoltage (mains failure)

– Output overvoltage

Power Down used as inhibit to enable a system start-up in

case of subsequently connected step-down converters

PSK/PSR with low start-up voltage. (For CQ units no pull-

up resistor is required.)

– Output short circuit

– Internal overtemperature

– Internal circuit fault

System Good

The system good signal provides information about the

general function of the T 1000.

– Inhibit/Ucr remote control input error such as (inhibit)

voltage < 2.5 V (rectifier type); control voltage out of

range 5.3 V > U_cr> 14 V (battery charger type) or sensor

not connected, open remote control input.

It can be used to monitor the status of a single T unit or can

be linked with other signals within a power system to drive

one single logic signal for the status of the whole system by

Table 15: Characteristics of the system good input and output

Characteristics

Conditions

min

typ

max

6.2

Unit

µA

V

I_Trig

U_Trig

I_Trig

U_Trig

I_sys

Trigger level for logic

low input (= System OK)

current driven

voltage driven

current driven

voltage driven

U_{i min}...U_{i max}

T_{C min}...T_{C max}

100

– 0.4

Trigger level for logic

high input (= System Failure)

0

A

>7.5

60

50

V

Output sink current ¹

mA

V

U_sat

U_Z

Saturation voltage

I_{Sys Out}= 50 mA

0.2

Zener voltage protection diode

Power disipation Zener diode

62

P_Z

T_C= 95°C

500

mW

¹To be limited to 50 mA by the external circuitry.

Signal input:

Signal output:

The system good input (Sys In) can be voltage or current

driven. To trigger the internal comparator, the voltage at the

Sys In pin has to be <6.2 V if voltage driven. If current

driven, the sink current to Vo– has to be >100 µA. An easy

way to drive the system good input is achieved by means of

an open collector transistor, or a 10 V CMOS interface.

(See figures below)

The system good signal output (Sys Out) is an open collec-

tor transistor referenced to Vo–, protected by a 62 V zener

diode. The output is well suited for relay applications.

06060

12

Vo+

Sys Out

Note: If only the internal status of a T unit is to be moni-

tored, Sys In has to be connected to Vo–.

26

22

No external free-

wheeling diode across

relay necessary

06057

Vo–

Vo+

T 1000

Logic high if no internal

T unit error and no inhibit

12

Fig. 34

I_{Sys Out}

Sys Out

26

System status signal electrically isolated by an external

relay

Logic AND

Ref.

+

I_{Sys In}

Sys In

24

–

Logic high if

I_{Sys In}> 100 µA

Vo–

22

Fig. 33

Equivalent circuit of system good input and output

Edition 4/4.99

18/33

MELCHER

The Power Partners.

Rugged Environment

AC-DC Converters >100Watt

T Series

Paralleling of Power Down and System Good

(Example)

Connection in Series of Power Down and System

Good (Examples)

To achieve a logic AND function of the System Good and

Power Down connect the D output with the system good

output. This combination generates an output signal only in

case of severe system errors. Only a T system fault to-

gether with a simultaneous Power Down of the output volt-

age will cause this output signal to become high imped-

To achieve a logic OR function of the system good and

power down signal connect the D output to Sys In. The de-

sired function is then obtained from the system good out-

put. The output signal becomes high if the output voltage is

lower than the threshold of the power down circuit, inhibit is

applied or an internal error has occurred.

ance.

06061

06062

Vo+

20/22

Vo–

20/22

Vo–

T 1000

24

Sys In

R

24

Sys In

R

26

Sys Out

26

Sys Out

Internal

signals

Internal

signals

28

Inhibit

28

Inhibit

Vo+

30

D

30

D

32

D set

32

D set

Fig. 35

Fig. 37

System Good and Power Down connected in series.

Note: Output signal will indicate error at start-up.

System Good and Power Down connected in parallel.

1 k

Output

Control

Circuit

20 V

CQ1

CQ2

CQn

06059

Sys In

Vo+

12

Sys In

24

Vo+

12

24

1 k

Sys Out

26

Output

Control

Circuit

26

Overall

System

Good

20 V

Vo–

22

T 1000

1 k

Output

Control

Circuit

20 V

Fig. 36

Wired AND of electrically isolated open collector signals

(e.g. the OUT OK signal of CQ units) with the system

good signals of T units in series to achieve one signal

about the status of the whole system

Edition 4/4.99

19/33

MELCHER

The Power Partners.

T Series

AC-DC Converters >100Watt

Rugged Environment

Display Status of LEDs

LED Sys OK (green)

– Input overvoltage

corresponds to the system good signal. The LED is ON if no

internal or external error is detected.

– Input undervoltage (mains failure)

– Output overvoltage

– Output short circuit

– Output voltage below threshold U_t

– Internal overtemperature

LED U_oOK (green)

indicates the output voltage status. It corresponds to the

power down signal. The LED is ON as long as U_ohas ex-

ceeded the upper threshold level and has not fallen below

the low threshold level U_t.

– Internal circuit fault

– Inhibit/Ucr remote control input error such as:

– (inhibit) voltage <2.5 V rectifier type

– Remote control voltage out of range

(5.3 V > U_cr> 14 V) battery charger type

– Sensor not connected, open remote control input

LED Error (red)

is ON if one or more of the following conditions is detected:

Table 16: System monitoring

Signal status and LED display status depending on the situation of the various system elements

Possible Situation

Open collector output

LED

U_oOK

on

System Good Power Down

Sys OK

on

Error

off

All OK

low

2

3

2

No mains and battery OK or no mains and U_o> U_t

Unit inhibited and battery OK or unit inhibited and U_o> U_t

Internal error

high

off

on

System good input logic high

high

low

high

low

off

on

off

on

off

on

off

on ¹

off

No mains and battery low or no mains and U_o< U_t

Short circuit on LT output, U_o< 4 V

Current limit LT output, U_o> 4 V, U_o< U_t

2

on

Battery charger type T xx40: sensor not connected or out of range

high

on

¹LED is on until the output capacitors are discharged.

²Sys In connected to Vo–.

³Sys In not connected to Vo– (single T status monitoring) or system status monitoring (see: System Integration).

Edition 4/4.99

MELCHER

20/33

The Power Partners.

Rugged Environment

AC-DC Converters >100Watt

T Series

Auxilliary Functions

Connection in Parallel and in Series

06078

12

Vo+

The output of the T units may either be connected in series

or in parallel.

Connection in parallel: Current sharing between paralleled

units is ensured by the output characteristic slope. Several

T units may be connected in parallel.

T xx40

Sensor

200 k

i/Ucr

28

Vo–

Connection in series: A maximum of 2 T units may be con-

nected in series, however the resulting output voltage of up

to 110 V would no longer be SELV. For safety reasons the

installation at the output should be protected with supple-

mentary insulation (IEC/EN 60950).

22

Fig. 38

Sensors connected in parallel.

Sensors in parallel provide redundant voltage adjustment

in case of one of the sensors in open circuit or short circuit

(add. external components required)

Power Boosting, Redundant Configuration,

Hot Plug-in

For redundant configurations the outputs should be de-

coupled to protect the DC-bus in case of an internal short

circuit at the output of any of the paralleled T units.

To enable hot plug-in in systems decoupled with fuses the T

series is fitted with an NTC resistor limiting the reverse cur-

rent flowing into the discharged output capacitors (see:

Functional Description).

Decoupling may either be done using series diodes or us-

ing appropriate fuses in the output path of each T unit. If the

battery voltage is to be monitored, choose T units with op-

tion D.

For this purpose the pins 16 and 18 have to be connected

to Vo+ and Vo– respectively (see fig.: T xx40 with battery

back-up).

Decoupling diodes provide reverse polarity protection with

no reverse current in case of hot plug-in, but have the dis-

advantage of the forward voltage drop over the diode and

higher power loss.

Since pins 16 and 18 are leading pins, the output capacitors

are precharged through the internal NTC resistor prior to

any other pin making contact. This protects the connector

and prevents the DC bus voltage from dropping during hot

plug-in. Hot plugging should be done gently. Subsequent

hot plug-out/plug-in of a unit with a hot NTC should be

avoided as current limiting will be poor. After disconnecting

an operating unit it should be cooled down prior to recon-

necting to the bus to avoid damage of the fuse or the con-

verter.

For battery applications decoupling of the T units with fuses

is recommended since the voltage drop over the decoup-

ling diodes would decrease the float charge voltage of the

battery. In case of an internal short circuit at the output of a

charger unit the battery will deliver a very large current

causing the respective fuse to blow. The fuse should be

mounted in the positive power path of the converter since

the monitoring signals of the T units are referenced to the

negative path. The fuse type should be suitable for DC ap-

plication having a current rating of 20 A or more with high

breaking capability, e.g. Littlefuse, series 314.

Note: The internal NTC limits the reverse charge current

flowing into the output capacitors of a T unit when it is

plugged into a battery buffered bus. Should however the T

unit already be connected when the battery is switched to

the bus, the resulting charge current will not be limited. To

avoid the fuse to blow or a possible arc across the circuit

breaker, the T units should be switched on to the mains

prior to connecting the battery. With decoupling diodes, no

reverse charge current flows from the power bus into the T

output capacitors.

Several T xx40 battery charger units connected in parallel

can be controlled by a single voltage source or a single sen-

sor wired to the remote control inputs. If sensors are con-

nected in parallel (redundant configuration), they should be

decoupled by 200 kΩ resistors, (see fig.: Sensors con-

nected in parallel). An individual sensor for each paralleled

T unit is not recommended because current sharing is af-

fected by the sensor tolerance.

T xx40

The remote control input of the T xx40 units allows hot plug-

in to an operating battery system with a single sensor with-

out affecting the float charge voltage.

D set

T 1000

R

43k2

R

43k2

T 1000

(21k5)

Fuse

+

–

+

Fig. 40

T xx40 with battery back-up. Power Down signal monitor-

ing the battery voltage.

–

Fig. 39

T unit without battery back-up in redundant configuration

Edition 4/4.99

21/33

MELCHER

The Power Partners.

T Series

AC-DC Converters >100Watt

Rugged Environment

Battery Size and Ripple Current

Combination of T Units and CQ Units without Battery

Some consideration should be given to the selection of the

battery size. According to VDE 0510 part 2, the low fre-

quency ripple current of the floating charge current should

not exceed 5 A_rmsper 100 Ah capacity (0.05 C). The power

factor corrected single step conversion of the line input volt-

age to the low DC output voltage generates a ripple voltage

at the output of twice the input frequency, causing a ripple

current into the connected battery.

In a complete power system consisting of two or more T

units in parallel combined with Melcher CQ units it may be

desirable to have one common signal indicating the status

of the whole system.

The Melcher CQ units provide a galvanically isolated signal

Out OK. To obtain a logic AND all CQ Out OK signals

should be connected in series (see also fig.: Wired AND of

galvanically isolated open collector signals). Out OK– of the

first CQ unit should be connected to Vo–, Out OK+ of the

last CQ unit should be connected to pin Sys In of one of the

T units. Sys Out should be connected to Sys In of the next T

unit. If one of the units fails (T or CQ ) it will be indicated by

the overall System Good (see fig. below).

For systems where only a small battery back-up time is re-

quired, battery charging by one T unit may be sufficient (see

also fig. below).

For systems with more than one T unit charging the battery

please refer to the chapter: Back Plane.

If in a system with 2 redundant T units Power Down is de-

sired as one common signal, independent of a possible fail-

ure of one of the two T units, simply interconnect the D pins

of the two T units. In this way Power Down only becomes

active if both T units fail which would result in the bus volt-

age falling (see fig. below).

06081

T 1000

U_o: 56.0 V

Load

T 1000

Note: Consider the behaviour of the signalling in a system

with decoupling diodes or fuses in the case of a T-failure,

with the secondary in short circuit.

U_o: 56.0 V

–

+

T 1700-7D

U_orange

50.5...56.0 V

06082

Battery

CQ 1

–

P

N

Vo+

Vo–

+

–

+

Out OK–

Out OK+

Fig. 41

–

+

–

+

–

R

Alternative configuration for a larger system with a small

battery

Sys Out

Overall

System

Good

Sys In

D

CQ 2

If the ripple current is too high e.g. in the case of a smaller

battery to be connected to the system, a large capacitor

with low impedance can be connected in parallel with the

battery. Another possibility is to connect an additional im-

pedance to the battery line, e.g. a choke or an NTC-resistor

(30 A or 60 A chokes are available on request. Please con-

sult Melcher's application center). Further considerations

for the selection of battery size include desired back-up

time, required battery life, temperature range and maxi-

mum permissible discharge current. Consult the manufac-

turers of lead-acid batteries for the final selection.

P

N

+

R

–

Out OK–

Out OK+

Power

Down

Sys Out

D

CQ 3

+

Vo+

Vo–

–

P

N

Out OK–

Out OK+

Sys In

–

+

Fig. 42

Caution: Lead-acid batteries can generate certain

amounts of H₂and O₂gas which can form explosive gas

mixtures. Sufficient ventilation must be provided in bat-

tery cabinets and installation rooms.

Monitoring of overall System Good and Power Bus Down

in a redundant system

Local regulations must be observed. Further information

about designing battery systems is contained in VDE 0510,

part 2.

Edition 4/4.99

22/33

MELCHER

The Power Partners.

Rugged Environment

AC-DC Converters >100Watt

T Series

Low Battery Discharge Protection

Storing the System Good Signal

Since all monitoring functions are powered by the output of

the T unit or the battery in the case of a mains failure, Power

Down can be used to monitor the status of the battery and

to disconnect the load or part of it via the inhibit of the CQ

units when the battery voltage drops below the threshold

level of the Power Down. This prevents further discharge of

the battery. See also: Power Down.

For battery back-up systems located in inaccessible areas

it could be of interest to know, whether there has been a

Power Fail (interruption of the mains). To obtain this infor-

mation Sys Out should be connected to Sys In with a reset

button connected to Vo–. In this way a system failure like an

interruption of the mains will be stored at Sys Out until the

reset button is pressed.

+

–

+

06083

+

06084

+

Fuse

CQ

–

+

Vo+

HC+

HC–

Vo–

+

Out OK–

Out OK+

i

Fuse

Vo+

–

HC+

P

N

P

N

+

HC–

Vo–

+

Vo+

CQ

–

R

Out OK–

Out OK+

i

Sys Out

Sys In

+

P

N

P

N

Stored

Sys Out

–

D

–

Vo+

R

+

CQ

Sys Out

–

Temp. sensor

Reset

Out OK–

Out OK+

i

Sys In

D set

–

Fig. 44

43.2 kΩ

Storing the System Good signal

R

ext

+

–

Temp. sensor

Fig. 43

Disconnecting the loads at low battery voltage in case of

mains failure

06085

+5.1 V, 64 A (48 A*)

* For redundancy,

decoupling at the

CQ-outputs with

CQ

diodes is required.

24 V, 8 A

(4 A*)

12 V, 16 A

(8 A*)

CQ

N P

Fuse

T

CQ

1740-7DZ

T

Back-up

battery

48 V

+

–

1740-7DZ

Temp. sensor

48 V_nomPower Bus (SELV)

(50.5...56.5 V DC)

System

Controller

Power down

DC bus good

Output good

Fig. 45

UPS uninteruptable power supply system

Edition 4/4.99

23/33

MELCHER

The Power Partners.

T Series

AC-DC Converters >100Watt

Rugged Environment

±12 V, 4 A

+5.1 V, 32 A

+24 V, 5 A

CQ

1001-6R

CQ

PSB

1001-6R

2320-7R

245-7R

Vo+

T 1701

P

N

Vo–

48 V DC _nomPower Bus (SELV)

System

Controller

(53…56 V DC)

Power Down

DC bus good

Output good

M

Cooling fan

Lamps

PCB heating

Fig. 46

Front end with various loads (example)

Edition 4/4.99

24/33

MELCHER

The Power Partners.

Rugged Environment

AC-DC Converters >100Watt

T Series

Electromagnetic Compatibility (EMC)

A suppressor diode or a metal oxide VDR (depending upon

the type) together with an input fuse and an input filter form

an effective protection against high input transient voltages

which typically occur in most installations, but especially in

battery driven mobile applications. The T series has been

successfully tested to the following specifications:

Electromagnetic Immunity

Table 17: Immunity type tests

Phenomenon

Standard ⁴

Level

Coupling

mode ²

Value

applied

Waveform

Source

imped.

Test

procedure

In

Per-

oper. form.

1

Electrostatic

discharge

(to case)

IEC/EN

61000-4-2

4

contact discharge 8000 V_p

1/50 ns

330 Ω

10 positive and

10 negative

discharges

yes

air discharge

15000 V_p

1

Electromagnetic IEC/EN

3

antenna

10 V/m

AM 80%

1 kHz

n.a.

26…1000 MHz

yes

field

61000-4-3

1

Electrical fast

transient/burst

IEC/EN

61000-4-4

4

capacitive, o/c

2000 V_pbursts of 5/50 ns 50 Ω

1 min positive

1 min negative

transient per

yes

2.5/5 kHz over

15 ms; burst

direct,

i/c, +i/–i

4000 V_p

period: 300 ms

coupling mode

1

Surge

IEC/EN

61000-4-5

3

4

i/c

2000 V_p

1.2/50 µs

12 Ω

2 Ω

5 pos. and 5 neg.

surges per coupling

mode

yes

+i/–i

3

VDE 0160

II

+i/–i

2.3 • U_ip

0.1/1.3 ms

1700 J 3 pos. and 3 neg.

yes

max

impulses

6 repetition

1

Conducted

disturbances

IEC/EN

61000-4-6

3

i, o, signal wires

10 V_rms

(140 dBµV)

AM 80%

1 kHz

150 Ω

0.15...80 MHz

yes

¹Normal operation, no deviation from specifications

²i = input, o = output, c = case.

³Normal operation, short deviation from specs. possible

⁴Related and previous standards are referenced in: Technical Information: Standards

Electromagnetic Emission

The conducted noise emitted at the input of the T units

within the frequency range of 10 kHz to 30 MHz is below

level B according to CISPR 11/22/EN 55011/22 under all

operating conditions.

with an MDS-clamp and below level A, according to

CISPR 11/22/EN 55011/22 measured with an antenna.

The radiated noise of the T units between 30 MHz and

1 GHz will be reduced if the unit is built into a conductive

chromatized 19" rack, fitted with a Melcher front panel. For

units mounted otherwise, e.g. for wall mounting with option

B1 (base plate) the radiated noise may be above level A.

The radiated noise in the frequency range of 30 MHz to

300 MHz on the input- and the output-side of the T units

stays below the limit of CISPR 14/EN 55014 measured

[dBµV]

90

[dBµV/m]

50

07035

07039

A

80

A

40

70

B

60

30

20

10

50

40

30

20

10

[MHz]

0

MHz

Fig. 47

Fig. 48

Typical disturbance voltage (quasi-peak) at the input of a

T series AC-DC converter according to CISPR 11/22 and

Typical radiated electromagnetic field strength (quasi peak)

of an LT 1740 according to CISPR 11/22/EN 55011/22, nor-

malized to a distance of 10 m, measured on an open area

EN 55011/22, measured at U_{i nom}and I_{o nom}

.

test site at U_{i nom}and I_{o nom}

.

Edition 4/4.99

25/33

MELCHER

The Power Partners.

T Series

AC-DC Converters >100Watt

Rugged Environment

Immunity to Environmental Conditions

Table 18: Mechanical stress

Test method

Standard

Test conditions

Status

Ca

Ea

Eb

Fc

Damp heat

steady state

IEC/DIN IEC 60068-2-3

Temperature:

Relative humidity:

Duration:

40 ^±2°C

%

56 days

Unit not

operating

93 ^+2/-3

Shock

(half-sinusoidal)

IEC/EN/DIN EN 60068-2-27

IEC/EN/DIN EN 60068-2-29

IEC/EN/DIN EN 60068-2-6

Acceleration amplitude:

Bump duration:

Number of bumps:

100 g_n= 981 m/s²

6 ms

18 (3 each direction)

Unit

operating

Bump

(half-sinusoidal)

Acceleration amplitude:

Bump duration:

Number of bumps:

40 g_n= 392 m/s²

6 ms

6000 (1000 each direction)

Unit

operating

Vibration

(sinusoidal)

Acceleration amplitude:

0.21 mm (10...60 Hz)

3 g_n= 29.4 m/s²(60...2000 Hz) operating

10...2000 Hz

Unit

Frequency (1 Oct/min):

Test duration:

7.5 h (2.5 h each axis)

Fda Random vibration IEC 60068-2-35

Acceleration spectral density: 0.05 g_{n rms}

Unit

wide band

Reproducibility

high

DIN 40046 part 23

Frequency band:

Acceleration magnitude:

Test duration:

20...500 Hz

4.9 g_{n rms}

3 h (1 h each axis)

operating

Kb

Salt mist, cyclic

(sodium chloride

NaCl solution)

IEC/EN/DIN IEC 60068-2-52

Concentration:

Duration:

Storage:

Storage duration:

Number of cycles:

5% (30°C)

Unit not

operating

2 h per cycle

40°C, 93% rel. humidity

22 h per cycle

3

Table 19: Temperature specifications

Temperature

–7

Characteristic

T_AAmbient operational

Conditions

min

–25

typ

max

71

Unit

I_o= 0...I_{o nom}

°C

temperature range

I_o> I_{o nom}

65

Temperature range

for battery charging

limited by U_crrange

T_C

Case operational

I_o= 0...I_{o nom}

–25

95

90

temperature range

at measurement point

(see: Mechanical Data)

I_o> I_{o nom}

–25

T_S

Storage temperature

range (not operating)

–40

100

T_Cs

Shut down

case temperature

100

0.5

1

R_{th CA}Thermal resistance

case to ambient

convection

cooling

K/W

h

τ_C

Thermal time constant

of case

Table 20: MTBF

Values at specified

case temperature

Module types

Ground benign

Ground fixed

Ground mobile

Unit

40°C

70°C

50°C

MTBF ¹

LT 1701-7

198'000

56'000

26'000

20'000

h

Device hours ²

810'000

¹Calculated in accordance with MIL-HDBK-217E (calculation according to edition F would show even better results)

²Statistical values, based on an average of 4300 working hours per year and in general field use, over 3 years

Edition 4/4.99

MELCHER

26/33

The Power Partners.

Rugged Environment

AC-DC Converters >100Watt

T Series

Environmental Conditions

Thermal Considerations

Despite the fact that the T series have a very high efficiency

the operating losses of the unit will heat the case. The heat

sinks are designed to dissipate the power losses at maxi-

mum output power over the specified temperature range

without forced cooling if the convection cooling provides

sufficient air volume, without obstructions for vertical air ex-

change below and above the units.

b) Unit operating with forced cooling (dotted line).

Under these conditions, the case temperature of the T

unit is decisive. With sufficient cooling provided (air

flow!), the unit still delivers 550 Watts output power in

voltage regulation mode even at 85°C ambient tempera-

ture, provided that the maximum case temperature of

95°C is not exceeded (Measuring point of case tempe-

rtature T_C, see: Mechanical Data). If the case tempera-

ture does not exceed 90°C, steady operation in output

power or current limitation mode is still possible. Never-

theless it is not recommended to operate the units con-

tinuously close to the maximum case temperature since

life time will be reduced.

Because of the slightly higher power losses in output power

and current limitation mode the maximum admissible am-

bient and case temperature is then lower than in output

voltage regulation mode.

The T series have a built-in overtemperature shut down to

protect the internal circuitry.

Since the operating temperature of a power supply is of

major importance to reliability the following conditions

should be considered:

Derating is required for applications with higher operational

ambient temperature. Fig.: Output power vs. ambient tem-

perature shows the derating of the output power versus op-

erational temperature above the specified ambient tem-

perature of 71°C of an LT 17xx unit. Two different condi-

tions are shown:

1. Do not cover heat sinks.

2. Do not obstruct air flow around the heat sinks.

3. Maximize free space around the units.

4. In a system where the power supplies as well as the

loads are located in the same enclosure, forced cool-

ing is recommended. The T units should be placed in

the lower section of the enclosure.

5. In a closed system heat may build up causing exces-

sive temperatures.

6. Always check the maximum ambient and case tem-

perature after system integration.

a) Unit operating with convection cooling (solid line).

For example if the operational ambient temperature

reaches 80°C, the maximum output power should be lim-

ited to approx. 290 W. In this case steady operation in

output power or current limitation mode is not possible.

P_{o max}

(convection

cooling)

08002

P_o[W]

550

290

P_loss[W]

P_{o max}

(forced cooling)

08003

Output voltage

regulation mode

45

Output power limitation

40

(I_o<10 A)

Output current limitation

35

30

Output power/current

limitation mode

(I_o>10 A)

25

Output voltage regulation

20

0

T_A[°C]

–25

50

60

70

80

90 95 100

15

10

5

Fig. 49

Output power versus ambient temperature of T 17xx

0

P_o[W]

600

U_i= 230 V_rms

0

100

200

300

400

500

U_i= 110 V_rms

Fig. 50

Internal power losses versus nominal output power of

T 17xx

Edition 4/4.99

27/33

MELCHER

The Power Partners.

T Series

AC-DC Converters >100Watt

Rugged Environment

Mechanical Data

Dimensions in mm. Tolerances ±0.3 mm unless otherwise indicated.

European

Projection

1.5

09036

System (ok) (green)

(ok) (green)

U

o

Testsockets

Error LED (red)

26.8

28 TE/141.5

60

T

30

Fixtures for retention clips

"V" for female connector

Measuring point 1

of case temperature T_c

Trim-potentiometer (T xx40)

Cell voltage selector switch Z (T xx40)

Input fuse (Option)

0.73

5¹/

2 TE

0.3

8 ¹/

2

TE

28 TE /142.2

Fig. 51

Case T01, weight 3.0 kg

Edition 4/4.99

28/33

MELCHER

The Power Partners.

Rugged Environment

AC-DC Converters >100Watt

T Series

12.35

5

158

12

ø 4.5

M4

17.3

133.4

168.5

5

119

8

171.93 (DIN 41494)

Measuring point of case temperature T_c

Front

panel

Fig. 52

Case T01 with option B1 (cooling plate)

09044

15

12

25 ^{± 0.2}

l

≤60

adhesive tape

l: 2 m standard length

other cable lengths on request

Fig. 53

Temperature sensor with mounting fixture.

Edition 4/4.99

29/33

MELCHER

The Power Partners.

T Series

AC-DC Converters >100Watt

Rugged Environment

Safety and Installation Instructions

Table 21: H15 Connector pin allocation

Connector Pin Allocation

The connector pin allocation table defines the electrical

potentials and the physical pin positions on the H15 con-

nector. Pin no. 8 and pin no. 10, the protective earth pins

present on all T series AC-DC converters are leading, en-

suring that they make contact with the female connector

first.

Pin Electrical determination

Designation

4

6

8

Phase

P~

N~

Neutral

Protective earth ¹

10 Protective earth ¹

12 Output voltage positive

Vo+

14 Output voltage positive

4

16 Hot plug-in contact ^{1 3}positive

18 Hot plug-in contact ^{1 3}negative

20 Output voltage negative

22 Output voltage negative

24 System good signal input

26 System good signal output

28 Inhibit input ²or Remote control input

30 Power down signal

HC+

HC–

Vo-

6

8

10

12

14

16

18

20

22

24

26

28

30

32

Vo-

Sys In

Sys Out

i/U_cr

D

Fig. 54

32 Power down signal threshold of U_o

D set

View of module’s male H15 connector

¹Leading pin (pre-connecting).

²Unit operates with open inhibit.

³External connections see: Auxiliary Functions: Power Boosting,

Redundant Configuration, Hot Plug-in.

Installation Instruction

The T series AC-DC converters are components, intended

exclusively for inclusion within other equipment by an in-

dustrial assembly operation or by professional installers. In-

stallation must strictly follow the national safety regulations

in compliance with the enclosure, mounting, creepage,

clearance, casualty, markings and segregation require-

ments of the end-use application. See also: Technical Infor-

mation: Installation and Application.

Important: Do not open the modules, or guarantee will

be invalidated.

Caution: Prior to handling, the AC-DC converter must

be disconnected from mains and from other sources

(e.g. batteries). Check for hazardous voltages and haz-

ardous energy before and after altering any connec-

tions. Hazardous energy levels may be present at the

output terminals for 3 minutes even after the mains input

voltage has been disconnected from the unit. This is in-

dicated by the red error LED. It is the responsibility of the

installer to prevent an unwanted short-circuit of the AC-

DC converter and of the batteries. To prevent an un-

wanted short-circuit across the output of a disconnected

unit, pins 16 and 18 are leading. In case of a short-circuit

across the output of a T-unit, all LEDs will be off, though

the mains may be present.

Connection to the system shall be made via the female con-

nector H15 (see: Accessories) according to: Connector pin

allocation. Other installation methods may not meet the

safety requirements.

Check for hazardous voltages before altering any connec-

tions.

The AC-DC converters are provided with pins 8 and 10

(

), which are reliably connected to the case. For safety

reasons it is essential to connect at least one of these pins

to the protective earth of the supply system.

Due to high output current value, the T series AC-DC con-

verters provide for each the positive and the negative out-

put path two internally parallel connected contacts (pins 12/

14 and pins 20/22 respectively). It is recommended to con-

nect the load to both female connector pins of each path in

order to keep the voltage drop and power loss across the

connector pins to an absolute minimum.

The P~ input (pin no. 4) is internally fused. This fuse is de-

signed to protect the unit in case of overcurrent and may

not be able to satisfy all customer requirements. External

fuses in the wiring to one or both input pins (no. 4 and/or no.

6) may therefore be necessary to ensure compliance with

local requirements. A second fuse in the wiring to the neu-

tral terminal N~ is needed if:

If a T series AC-DC converter is used for battery charging,

check wether the position of the cell voltage selector switch

corresponds to the required battery cell voltage prior to

putting a system into operation.

•

Local requirements demand an individual fuse in each

source line

•

Neutral to earth impedance is high or undefined

Phase and neutral of the mains are not defined or cannot

be assigned to the corresponding terminals (L to phase

and N to neutral).

Caution: Lead-acid batteries can generate H₂and O₂

gas which can form explosive mixtures. Sufficient venti-

lation must be provided in battery cabinets and installa-

tion rooms.

Edition 4/4.99

30/33

MELCHER

The Power Partners.

Rugged Environment

AC-DC Converters >100Watt

T Series

Further information about designing battery systems is con-

tained in VDE 0510, part 2.

the function of the unit nor is it detrimental to its perform-

ance over time.

If a T unit is to be parallel connected with another T unit, it is

recommended to connect the two hot plug-in pins of each

female connector, HC+ (pin 16) and HC– (pin 18) to their

respective output pins Vo+ and Vo- to provide the hot plug-

in capabilities.

Standards and approvals

All T series AC-DC converters correspond to class I equip-

ment. They are UL recognized according to UL 1950, UL

recognized for Canada to CAN/CSA C22.2 No. 950-95 and

LGA approved to IEC/EN 60950 standards and have been

evaluated in accordance with these standards for:

In case of remote temperature control, the temperature

sensor should be connected according to its wiring dia-

gram. Wrong connection may damage the sensor.

•

Building in

Basic insulation between input and case, based on

250 V AC

Make sure that there is sufficient air flow available for con-

vection cooling. This should be verified by measuring the

case temperature when the unit is installed and operated in

the end-use application. The maximum specified case tem-

perature T_{C max}must not be exceeded. See also: Thermal

Considerations.

•

Double or reinforced insulation between input and out-

put, based on 250 V AC

•

Operational insulation between output and case

The use in a pollution degree 2 environment

Connecting the input to a primary circuit with a maxi-

mum transient rating of 2500 V (overvoltage class III

based on a 110 V primary circuit, overvoltage class II

based on a 230 V primary circuit).

If the end-product is to be UL certified, the temperature test

may be repeated asv part of the end-product investigation.

Ensure that a unit failure (e.g. by an internal short-circuit)

does not result in a hazardous condition. See also: Safety

of operator accessible output circuit.

The AC-DC converters are subject to manufacturing sur-

veillance in accordance with the above mentioned UL,

CSA, EN and with ISO 9001 standards.

Cleaning Agents

Isolation

In order to avoid possible damage, any penetration of

cleaning fluids is to be prevented, since the power supplies

are not hermetically sealed.

The electric strength test is performed as factory test in ac-

cordance with IEC/EN 60950 and UL 1950 and should not

be repeated in the field. Melcher will not honour any guar-

antee claims resulting from electric strength field tests.

Audible Noise

Under certain operating conditions, a T series AC-DC con-

verter may generate a slight audible noise due to magneto-

striction in the transformer. This noise does neither affect

Important: Testing by applying AC voltages will result in

high and dangerous leakage currents flowing through

the Y-capacitors (see fig.: Block diagram).

Table 22: Isolation

Characteristic

LT/UT AC-DC converter

Sensor

Unit

Input to

case

Input to

output

Output to

case

Output to

case

Electric

strength

test voltage

Required according to IEC/EN 60950

Actual factory test 1 s

1.5

2.1

2.8

2.0

3.0 ¹

4.2 ¹

5.6 ¹

4.0 ¹

0.5

0.7

1.4

1.0

kV_rms

0.7

kV DC

1.4

AC test voltage equivalent to actual

factory test

1.0

kV_rms

Insulation resistance at 500 V DC

>300

>100

MΩ

¹In accordance with IEC/EN 60950 only subassemblies are tested in factory with this voltage.

Leakage Currents in AC-DC operation

1500 Ω

MI

Leakage currents flow due to internal leakage capacitance

and RFI suppression Y-capacitors. The current values are

500 Ω

proportional to the mains voltage and nearly proportional to

the mains frequency. They are specified at maximum oper-

ating input voltage where phase, neutral and protective

earth are correctly connected as required for class I equip-

ment.

10 kΩ

220 nF

Under test conditions, the leakage current flows through a

22 nF

measuring instrument (MI) as described in fig.: Measuring

instrument for earth leakage current tests, which takes into

account impedance and sensitivity of a person touching

V

unearthed accessible parts. The current value is calculated

by dividing the measured voltage by 500 Ω. If inputs and/or

outputs of T units are connected in parallel, their individual

Fig. 55

Measuring instrument (MI) for earth leakage current tests

according to IEC/EN 60950, Annex D.

leakage currents are added.

Edition 4/4.99

31/33

MELCHER

The Power Partners.

T Series

AC-DC Converters >100Watt

Rugged Environment

10070

10071

L1

L2

P

N

Vo+

L1

L2

P

N

P

N

Vo–

S1

L2

N

Vo+

LT 1000

T 1000

Vo–

MI for

earth

leakage

current

MI for

earth

leakage

current

S2

S3

S2

S3

MI for

output

MI for

output

leakage

current

leakage

current

Fig. 56

Fig. 57

Test set-up for leakage current tests on class I equipment

in single phase configuration. S1 is used to simulate the

interchanging of phase and neutral, S2/3 select either the

earth or output leakage current measurements, S4 selects

either the positive or negative output leakage current

measurements.

Test set-up for leakage current tests on class I equipment

in 208 V phase to phase configuration. S2/3 select either

the earth or output leakage current measurements, S4

selects either the positive or negative output leakage cur-

rent measurements.

Table 23: Leakage currents

Characteristic

T 1000

3.5

Unit

Earth leakage

current

Permissible according to IEC/EN 60950

Specified value at 255 V, 50 Hz (LT)

Specified value at 127 V, 60 Hz (LT or UT)

Permissible according to IEC/EN 60950

Specified value at 255 V, 50 Hz (LT)

Specified value at 127 V, 60 Hz (LT or UT)

mA

1.8 ¹

1.1 ¹

0.25

<0.1

Output leakage

current

¹In phase to phase configuration, leakage current is lower.

Safety of operator accessible output circuit

If the output circuit of an AC-DC converter is operator ac-

cessible, it shall be an SELV circuit according to IEC/EN

60950 related safety standards

However, it is the sole responsibility of the installer to as-

sure the compliance with the relevant and applicable safety

regulations. More information is given in: Technical Infor-

mation: Safety.

The following table shows a possible installation configura-

tion, compliance with which causes the output circuit of the

AC-DC converter to be an SELV circuit according to IEC/

EN 60950 up to a configured output voltage (sum of nomi-

nal voltages if in series or +/– configuration) of 56.5 V.

Protection Degree

IP 30 if female connector is fitted to the unit.

Table 24: Safety concept leading to an SELV circuit

Conditions

AC-DC converter

Installation

Result

Supply voltage

Grade of isolation between input and

output, provided by the AC-DC

converter

Measures to achieve the resulting

safety status of the output circuit

Safety status of the AC-DC

converter ouput circuit

Mains ≤250 V AC

Double or reinforced

Installation according to the appliable

standards

SELV circuit

10021

Fuse

Vo+

P~

+

P

N

AC-DC

Mains

SELV

Fuse

con-

–

N~

Vo–

verter

Earth connection

Fig. 58

Schematic safety concept

Use input fuses and earthing of the AC-DC converter as

per: Installation Instructions.

Edition 4/4.99

32/33

MELCHER

The Power Partners.

Rugged Environment

AC-DC Converters >100Watt

T Series

Description of Options

D Remote Bus Voltage Monitoring

F Externally Accessible Fuse

This option is designed for systems using Melcher back-

planes or is inteded for use in applications where a fuse or a

decoupling diode is fitted into the positive supply line to the

system bus. The status of the system bus/battery voltage

can be monitored rather than the output status of a single T

unit. To maintain the adjustment capabilities and resistor

values for setting the different threshold values a 43.2 kΩ

(21.5 kΩ) resistor should be fitted into the sense line to the

bus. If the D set pin is left open the T unit signals perma-

nently Low Bus Voltage.

The standard T units have internally a 5 × 20 mm fuse

which is externally not accessible. Some applications re-

quire an externally accessible fuse. Option F provides a

fuse mounted on the back plate neer the converter. The full

self-protecting functions of the module do normally not lead

to broken fuses, except as a result of overvoltage at the in-

put or if a power component inside fails (switching transis-

tor, freewheeling diode, etc.). In such cases the defective

unit has to be returned to Melcher for repair.

B1 Cooling Plate

(See also: Power Down as well as data sheet: Back Planes

for the T Series)

If a cooling surface is available the T 1000 units can be pro-

vided with a mounting plate (option B1) instead of the

standard heat sink fitted to the right hand side of the unit.

Since approximately 50% of the losses have to be dissi-

pated through the heat sink on the left hand side sufficient

free air flow has still to be provided.

Accessories

A variety of electrical and mechanical accessories are

available, including:

– Front panels for 19" rack mounting, Schroff system

– Mating H15 connectors with screw, solder, fast-on or

pressfit terminals

– Connector retention facilities

– Code key system for connector coding

– 19" racks for system integration

– Back planes for system integration

– Temperature sensors for battery charging

Back planes for system intergration

For more detailed information refer to: Accessory Products.

19" Rack

Front panels

H15 female connector

Code system

Edition 4/4.99

33/33

MELCHER

The Power Partners.


型号：	LT1840-7DFB1
厂家：	BEL FUSE INC.
描述：	AC-DC Regulated Power Supply Module, 1 Output, 450W, CASE T01, MODULE
文件：	总33页 (文件大小：838K)
中文：	中文翻译
下载：	下载PDF数据表文档文件

LT1840-7DFB1 [BEL]

相关型号：

LT1840-7DZB1

LT1840-7DZF

LT1840-7DZFB1

LT1840-7FB1

LT1840-7ZB1

LT1840-7ZD

LT1846

LT1846J

LT1846N

LT1847

LT1847J

LT1847N