Puls Dimension CD, Dimension CD5.242, Dimension CD5.241, Dimension CD5.241-S1, CD5.242 Series Manual

CD–Series

1. GENERAL DESCRIPTION

The Dimension CD5-Series offers a range of DIN-rail
mountable DC/DC-converters in a very compact
housing.

The CD5.242 converts a 48V voltage to a 24V
voltage. The input source can be a battery, a solar
panel or any other 48V sources.

The CD5.242 includes all the essential basic functions
and has a power reserve of 20% included. This extra
power can be used continuously up to +45°C.

The output is electrically isolated from the input in a
safe way. The input is protected against reversed
voltages and contains a soft start funtion.

CD-Series

Related products

24V->24V

CD5.241-S1

24V->24V

CD5.241 CD5.121

24V->12V

48V->24V

CD5.242

Spring-clamp
terminals,
Input-low,
DC-OK
contacts

CD5.242

DC/DC Converter; 24V, 5A

DC/DC CONVERTER

■ Wide Range DC Input (36-60Vdc)

■ Isolated 24Vdc Output

■ Efficiency up to 90.3%

■ Width only 32mm

■ 20% Output Power Reserves

■ Full Output Power Between -25°C and +60°C

■ Soft-start Function Included

■ Minimal Inrush Current Surge

■ Reverse Input Polarity Protection

■ 3 Year Warranty

2. SHORT-FORM DATA

Output voltage DC 24V
Adjustment range 23 - 28V
Output current

Output power 120W Ambient <60°C
144W Ambient <45°C
Output ripple < 50mVpp 20Hz to 20MHz
Input voltage DC 48V 36 to 60Vdc

Input current typ. 2.75A At 48Vdc input
Input inrush current typ. 0.6A peak
Efficiency typ. 90.3% At 48Vdc input
Losses typ. 12.9W At 48Vdc input
Hold-up time typ. 5.6ms At 48Vdc input
Temperature range -25°C to +70°C Operational
Derating 3W/°C +60 to +70°C
Dimensions 32x124x102mm WxHxD

5 – 4.3A
6 – 5.1A

Ambient <60°C
Ambient <45°C

(30.5 to 36Vdc
with derating)

3. ORDER NUMBERS

DC/DC
Converter

Accessories ZM1.WALL Wall mount bracket
ZM11.SIDE Side mount bracket

YR2.DIODE Decoupling module

July 08 / Rev. 1.2 DS-CD5.242-EN / All parameters are specified at 24V, 5A and 48Vdc input at 25°C ambient unless otherwise noted.

CD5.242

YRM2.DIODE Redundancy module

Standard unit

www.pulspower.com Phone [phone] Germany

4. MARKINGS

LISTED

IND. CONT. EQ.

UL 508

CUS

182790

18WM

R

UL 60950-1

Marine

GL

Class I Div 2,

pending

EMC, LVD

1/21

CD–Series

DC/DC Converter; 24V, 5A

CD5.242

INDEX PAGE INDEX PAGE

1. General Description ............................................1

2. Short-form Data ..................................................1

3. Order Numbers....................................................1

4. Markings..............................................................1

5. Input Voltage ......................................................3

6. Soft-start and Input Inrush Current Surge .........4

7. Output .................................................................5

8. Hold-up Time.......................................................6

9. Efficiency and Power Losses................................7

10. Functional Diagram.............................................8

11. Reliability.............................................................8

12. Front Side and User Elements.............................9

13. Terminals and Wiring..........................................9

14. EMC....................................................................10

15. Environment......................................................11

16. Protection Features...........................................12

17. Safety .................................................................12

18. Dielectric Strength ............................................12

19. Approvals...........................................................13

20. Fulfilled Standards ............................................13

21. Used Substances ............................................... 13

22. Physical Dimensions and Weight..................... 14

23. Installation and Operation Instructions .......... 14

24. Accessory........................................................... 15

25. Application Notes............................................. 16

25.1. Peak Current Capability......................... 16

25.2. Back-feeding Loads................................ 16

25.3. Inductive and Capacitive Loads ............. 16

25.4. Output Circuit Breakers ......................... 17

25.5. Series Operation..................................... 18

25.6. Parallel Use to Increase Output Power . 18

25.7. Daisy Chaining of Outputs..................... 18

25.8. Parallel Use for 1+1 Redundancy........... 19

25.9. Charging of Batteries............................. 19

25.10. Requirements for the Supplying Source 20

25.11. External Input Protection....................... 20

25.12. Use in a Tightly Sealed Enclosure .......... 20

25.13. Mounting Orientations.......................... 21

INTENDED USE

The DC/DC converter shall only be installed and put into operation by qualified personnel.
This DC/DC converter is designed for installation in an enclosure and is intended for the general use, such as in

industrial control, office, communication, and instrumentation equipment. Do not use this device in aircraft, trains
and nuclear equipment, where malfunctioning of the DC/DC converter may cause severe personal injury or threaten
human life.

TERMINOLOGY AND ABREVIATIONS

PE and symbol PE is the abbreviation for Protective Earth and has the same meaning as the symbol .

Earth, Ground This document uses the term “earth” which is the same as the U.S. term “ground”.

T.b.d. To be defined, value or description will follow later.

DC 24V A figure displayed with the AC or DC before the value represents a nominal voltage with

standard tolerances included.
E.g.: DC 12V describes a 12V battery regardless whether it is full (13.7V) or flat (10V)

24Vac A figure with the unit (Vdc) at the end is a momentary figure without any additional

tolerances included.

DISCLAIMER

The information presented in this document is believed to be accurate and reliable and may change without notice.
Some parts of this unit are patent by PULS (US patent No 091662,063, Des. 424,529, …).
No part of this document may be reproduced or utilized in any form without permission in writing from PULS GmbH.

July 08 / Rev. 1.2 DS-CD5.242-EN / All parameters are specified at 24V, 5A and 48Vdc input at 25°C ambient unless otherwise noted.

www.pulspower.com Phone [phone] Germany

2/21

CD–Series

DC/DC Converter; 24V, 5A

CD5.242

5. INPUT VOLTAGE

Input
Input voltage range
typ. 30.5-36.0Vdc Max. 60 seconds or with de-rating, see Fig. 5-2

Allowed voltage between input
and earth (ground)

Allowed input ripple voltage

Turn-on voltage typ. 34.5Vdc Steady-state value, see Fig. 5-1
Shut-down voltage typ. 30.5Vdc Steady-state value, see Fig. 5-1

Input current
Start-up delay typ.
Rise time typ. 80ms 0mF, 24V, 5A, constant current load, see Fig. 5-3

Turn-on overshoot
Input capacitance typ.

External capacitors on the input voltage bus are allowed without any limitations.

Fig. 5-1 Input voltage range

P

OUT

Shut-down

30.5Vdc

Rated input range

Turn-on

35.0Vdc

36.0Vdc

Fig. 5-3 Turn-on behavior, definitions Fig. 5-4 Input current vs. output load

Intput
Voltage

Output
Voltage

- 5%

Start-up

delay

Rise

Time

nom. DC 48V
nom. 36.0-60.0Vdc Continuous operation

max. 63.0Vdc Absolute maximum continuous input voltage with no

damage to the DC/DC converter. Please note that the unit
can switch off above 60Vdc

max. 60Vdc or

42.4Vac

max. 5Vpp 47Hz-40kHz, the momentary input voltage must always be

within the specified limits.

typ. 63.5Vdc Steady-state value, see Fig. 5-1
typ. 2.75A At 48Vdc input and output 24V, 5A, see Fig. 5-4

670ms

0mF, 24V, 5A, constant current load, see Fig. 5-3

typ. 150ms 5mF, 24V, 5A, constant current load, see Fig. 5-3

60.0Vdc

500mV
800µF

V

IN

63.5Vdc

Overshoot

See Fig. 5-3

Fig. 5-2 Allowable output current below 36V

Output Current

6A

5

4

3

2

1

0

30 32 34 36 40Vdc

Input

4A

Current,
typ.

3

2

1

0

1

1.5 2 3

input voltage

(a) Ambient < 45°C
(b) Ambient < 60°C

Input Voltage

Output Current

3.5

2.5

u

p

n

I

n

I

4

t

p

4.5

)

a

(

)

b

(

38

c

d

V

6

3

:

V

8

4

:

t

u

5

d

5.5

c

6A

max.

July 08 / Rev. 1.2 DS-CD5.242-EN / All parameters are specified at 24V, 5A and 48Vdc input at 25°C ambient unless otherwise noted.

www.pulspower.com Phone [phone] Germany

3/21

CD–Series

DC/DC Converter; 24V, 5A

CD5.242

6. SOFT-START AND INPUT INRUSH CURRENT SURGE

Inrush current limitation

An active inrush limitation circuit (inrush limiting resistor which is bypassed by a relay contact) limits the input inrush
current after turn-on of the input voltage.

The charging current into EMI suppression capacitors is disregarded in the first microseconds after switch-on.

Inrush current

max. 0.8A
typ. 0.6A
Inrush energy

typ. negligible -25°C to +70°C

Fig. 6-1 Input inrush current, typical behavior

Input Current

Input Voltage

Input 48Vdc

-25°C to +70°C

peak

-25°C to +70°C

peak

Input: 48Vdc
Output: 24Vdc, 5A, constant current load
Ambient: 25°C

Upper curve: Input current 1A / DIV
Middle curve: Input voltage 50V / DIV
Lower curve: Output voltage 20V / DIV
Time scale: 100ms / DIV

Output Voltage

Soft-start function:

After the DC/DC converter is turned on, the internal output current rises slowly to its nominal value. This method
charges the output capacitors (internal and external capacitors) slowly and avoids high input currents during turn-on.
High input currents can produce a high voltage drop on the input wiring (especially with long and thin cables) which
reduces the terminal voltage on the DC/DC converter. If the terminal voltage is below the shut-down voltage, the
DC/DC converter will turn-off and will make a new start-up attempt. This effect is avoided with the integrated soft­start function. Please note, that this function increases the rise time of the output voltage by a small amount.

Fig. 6-2 Soft-start behavior

Input: 48Vdc
Output: 24Vdc, 5A, constant current load
Ambient: 25°C
No additional external capacitors

Input Current

Upper curve: Input current 2A / DIV
Lower curve: Output voltage 10V / DIV
Time scale: 20ms / DIV

Output Voltage

July 08 / Rev. 1.2 DS-CD5.242-EN / All parameters are specified at 24V, 5A and 48Vdc input at 25°C ambient unless otherwise noted.

www.pulspower.com Phone [phone] Germany

4/21

A

c

CD–Series

DC/DC Converter; 24V, 5A

CD5.242

7. OUTPUT

Output voltage
Adjustment range
max. 30V At clockwise end position of potentiometer
Factory setting
Line regulation
Load regulation max. 100mV Static value, 0A Æ 5A Æ 0A
Ripple and noise voltage
Output capacitance typ.
Output current nom. 6A At 24V, ambient < 45°C, see Fig. 7-1
nom. 5A

Output power nom. 144W Ambient < 45°C
nom. 120W
Short-circuit current
max. 10A Load impedance 200mOhm, see Fig. 7-1

Fig. 7-1 Output voltage vs. output current,

typ. (48Vdc input voltage)

nom. 24V
min. 23-28V Guaranteed

max.

max.

24.1V
25mV

50mVpp
2200µF

±0.2%, at full load, cold unit

Input variations between 36 to 60Vdc

20Hz to 20MHz, 50Ohm

At 24V, ambient < 60°C, see

Fig. 7-1

nom. 5.1A At 28V, ambient < 45°C, see Fig. 7-1
nom. 4.3A

At 28V, ambient < 60°C, see

Fig. 7-1

Ambient < 60°C

min. 7A Load impedance 200mOhm, see Fig. 7-1

Fig. 7-2 Current limitation vs. input voltage,

typ. (23V constant voltage load)

Output Voltage

28V

24

20

16

12

8

4
0

Adjustment

Range

Output Current

048

1062

12

Output Current

7.0A

6.9

6.8

6.7

6.6

6.5

6.4

6.3

6.2
30 42 54

Input Voltage

4836

60Vd

Peak current capability (up to several ms)

The DC/DC converter can deliver a peak current which is higher than the specified short term current. This helps to
start current demanding loads or to safely operate subsequent circuit breakers.

The extra current is supplied by the output capacitors inside the DC/DC converter. During this event, the capacitors
will be discharged and cause a voltage dip on the output. Detailed curves can be found in chapter 25.1.

Peak current voltage dips typ. from 24V to 17.1V At 10A for 50ms, resistive load
typ. from 24V to 15V

typ. from 24V to 11V

At 20A for 2ms, resistive load
At 20A for 5ms, resistive load

July 08 / Rev. 1.2 DS-CD5.242-EN / All parameters are specified at 24V, 5A and 48Vdc input at 25°C ambient unless otherwise noted.

www.pulspower.com Phone [phone] Germany

5/21

CD–Series

DC/DC Converter; 24V, 5A

CD5.242

8. HOLD-UP TIME

The input side of the DC/DC converter is equipped with a bulk capacitor which keeps the output voltage alive for a
certain period of time when the input voltage dips or is removed. The bulk capacitor can be discharged by loading
the DC/DC converter on the output side or through a load which is parallel to the input. There is no protection in the
DC/DC converter which prevents current from flowing back to the input terminals. If prevention is needed, an
external diode should be used.

Input 48Vdc

Hold-up Time typ. 10.5ms Input 48Vdc, Output: 24Vdc, 2.5A, see
typ. 5.6ms Input 48Vdc, Output: 24Vdc, 5A, see Fig. 8-1

Fig. 8-1 Hold-up time vs. input voltage

Hold-up Time

12ms

10

8

6

4

2

0

Input Voltage

36 40 44 48 56Vdc

)

(

a

(

b

)

)

(

c

)

(

d

(a) 24V, 2.5A, typ.
(b) 24V, 2.5A, min.
(c) 24V, 5A, typ.
(d) 24V, 5A, min.

52

Fig. 8-2 Shut-down test setup Fig. 8-3 Shut-down behavior, definitions

DC/DC

Converter

S1

Input

Output

CD5

+

+

Load

-

-

DC

Source

+

-

Intput
Voltage

Output
Voltage

Fig. 8-1

S1 opens

- 5%

Hold-up Time

Note: At no load, the hold-up time can be up to several seconds. The green DC-ok lamp is also on during this time.

July 08 / Rev. 1.2 DS-CD5.242-EN / All parameters are specified at 24V, 5A and 48Vdc input at 25°C ambient unless otherwise noted.

www.pulspower.com Phone [phone] Germany

6/21

A

A

c

c

CD–Series

DC/DC Converter; 24V, 5A

9. EFFICIENCY AND POWER LOSSES

Input 48Vdc

Efficiency typ. 90.3% 5A, 24V
Power losses typ. 0.9W At no output load
typ. 6.9W 2.5A, 24V
typ. 12.9W 5A, 24V
typ. 16.4W 6A, 24V

Fig. 9-1 Efficiency vs. output current at 24V

output voltage and 48V input voltage

Efficiency

91%

90

89

88

87

86

85

1

Output Current

2453

6

Fig. 9-2 Losses vs. output current at 24V

output voltage and 48V input voltage

Power Losses

18W

15

12

9

6

3

0

012 456

Fig. 9-3 Efficiency vs. input voltage, 24V, 5A

Efficiency

91%

90.5

90.0

89.5

89.0

88.5

88.0
36 40 44 52 56 60

output

Input Voltage

48

Vd

Fig. 9-4 Losses vs. input voltage, 24V, 5A

Power Losses

18W

15

12

9

6

3

0

36 40 48 52 56 60

Output Current

3

output

Input Voltage

44

CD5.242

Vd

July 08 / Rev. 1.2 DS-CD5.242-EN / All parameters are specified at 24V, 5A and 48Vdc input at 25°C ambient unless otherwise noted.

www.pulspower.com Phone [phone] Germany

7/21

CD–Series

DC/DC Converter; 24V, 5A

CD5.242

10. FUNCTIONAL DIAGRAM

Fig. 10-1 Functional diagram

Output

Voltage

Regulator

+

Chassis

Ground

-

Input Fuse
&
Input Filter

Reverse
Polarity
Protection
&
Inrush
Limiter

Over-

Temperature

Protection

Output

Over-

Voltage

Protection

Power

Converter

Output

Filter

V

OUT

+
+

-

-

DC
ok

11. RELIABILITY

Input: 48Vdc

Lifetime expectancy min. 169 000h 40°C, 24V, 2.5A
min. 64 000h 40°C, 24V, 5A
min. 39 000h 40°C, 24V, 6A
min. 181 000h 25°C, 24V, 5A
MTBF SN 29500, IEC 61709 951 000h 40°C, 24V, 5A
1 560 000h 25°C, 24V, 5A
MTBF MIL HDBK 217F 559 000h 40°C, 24V, 5A, Ground Benign GB40
749 000h 25°C, 24V, 5A, Ground Benign GB25

The Lifetime expectancy shown in the table indicates the operating hours (service life) and is determined by the
lifetime expectancy of the built-in electrolytic capacitors. Lifetime expectancy is specified in operational hours.
Lifetime expectancy is calculated according to the capacitor’s manufacturer specification. The prediction model allows
a calculation of up to 15 years from date of shipment.

MTBF stands for Mean Time Between Failure, which is calculated according to statistical device failures, and indicates
reliability of a device. It is the statistical representation of the likelihood of a unit to fail and does not necessarily
represent the life of a product.

July 08 / Rev. 1.2 DS-CD5.242-EN / All parameters are specified at 24V, 5A and 48Vdc input at 25°C ambient unless otherwise noted.

www.pulspower.com Phone [phone] Germany

8/21

CD–Series

12. FRONT SIDE AND USER ELEMENTS

Fig. 12-1

Front side

A Output Terminals
Screw terminals

Dual terminals per pole
+ Positive output

- Negative (return) output

Input Terminals

B
Screw terminals
+ Positive input

- Negative (return) input
Chassis ground can be used to bond the housing to PE
Ground this terminal to minimize high-frequency emissions.

Output voltage potentiometer

C
Open the flap to set the output voltage. Factory set: 24.1V

D DC-OK LED (green)

On when the voltage on the output terminals is > 21V

CD5.242

DC/DC Converter; 24V, 5A

13. TERMINALS AND WIRING

Type Screw terminals
Solid wire 0.5-6mm
Stranded wire 0.5-4mm2
American wire gauge 20-10 AWG
Recommended tightening torque 1Nm, 9lb.in
Screwdriver 3.5mm slotted or Pozidrive No 2
Wire stripping length 7mm / 0.275inch

Instructions:

a) Use appropriate copper cables that are designed for an operating temperature of:

60°C for ambient up to 45°C and

75°C for ambient up to 60°C minimum.
b) Follow local and national installation codes and regulations!
c) Ensure that all strands of a stranded wire enter the terminal connection!
d) Up to two stranded wires with the same cross section are permitted in one connection point.
e) Ferrules are allowed but not required
f) In order to fulfill GL requirements, unused terminal spaces must be closed.

2

July 08 / Rev. 1.2 DS-CD5.242-EN / All parameters are specified at 24V, 5A and 48Vdc input at 25°C ambient unless otherwise noted.

www.pulspower.com Phone [phone] Germany

9/21

CD–Series

DC/DC Converter; 24V, 5A

CD5.242

14. EMC

The CE mark indicates conformance with EMC directive 89/336/EC, 93/68/EC and 2004/108/EC and the low-voltage
directive (LVD) 73/23/EC, 93/68/EC, 2006/95/EC. A detailed EMC Report is available on request.

EMC Immunity

Electrostatic discharge EN 61000-4-2 Contact discharge

Electromagnetic RF field EN 61000-4-3 80MHz-2.7GHz 10V/m Criterion A

Fast transients (Burst) EN 61000-4-4 Input lines

Surge voltage on input EN 61000-4-5 + Æ -

Surge voltage on output EN 61000-4-5 + Æ -

Conducted disturbance EN 61000-4-6 0,15-80MHz 10V Criterion A

Criterions:

A: DC/DC converter shows normal operation behavior within the defined limits.
C: Temporary loss of function is possible. DC/DC converter might shut-down and restarts by itself. No damage or hazards will occur

to the DC/DC converter.

EMC Emission

Conducted emission IEC/CISPR 16-1-2, IEC/CISPR 16-2-1 Class B, Input lines
(Limits for DC power ports)
Radiated emission EN 55011, EN 55022 Class B

This device complies with FCC Part 15 rules.
Operation is subjected to the following two conditions: (1) this device may not cause harmful interference, and (2) this
device must accept any interference received, including interference that may cause undesired operation.

Switching frequency

EN 61000-6-2, EN 61000-6-1

Air discharge

Output lines
Signal lines

+ / - Æ chassis ground

+ / - Æ chassis ground

EN 61000-6-3, EN 61000-6-4 Generic standards

90kHz to 140kHz (Output current > 0.5A) Input voltage and output current

Generic standards
8kV

15kV

4kV
2kV
2kV

1kV
2kV

500V
500V

dependent

Criterion A
Criterion A

Criterion A
Criterion A
Criterion A

Criterion A
Criterion A

Criterion A
Criterion A

July 08 / Rev. 1.2 DS-CD5.242-EN / All parameters are specified at 24V, 5A and 48Vdc input at 25°C ambient unless otherwise noted.

www.pulspower.com Phone [phone] Germany

10/21

C

CD–Series

DC/DC Converter; 24V, 5A

CD5.242

15. ENVIRONMENT

Operational temperature -25°C to +70°C (-13°F to 158°F) Reduce output power according to Fig. 15-1
Output de-rating 1.6W/°C 45-60°C (113°F to 140°F), see Fig. 15-1
3W/°C 60-70°C (140°F to 158°F), see Fig. 15-1
Storage temperature -40 to +85°C (-40°F to 185°F) During storage and transportation

Humidity 5 to 95% r.H. IEC 60068-2-30

Vibration sinusoidal 2-17.8Hz: ±1.6mm; 17.8-500Hz: 2g

Shock 30g 6ms, 20g 11ms

2 hours / axis

3 bumps / direction, 18 bumps in total

Altitude 0 to 6000m (0 to 20000ft) Reduce output power or ambient

Output de-rating (for altitude) 7.5W/1000m or 5°C/1000m Above 2000m (6500ft), see Fig. 15-2
Over-voltage category III EN 50178, altitudes up to 2000m
II Altitudes from 2000m to 6000m
Degree of pollution 2 EN 50178, non conductive

Fig. 15-1 Output current vs. ambient temp. Fig. 15-2 Output current vs. altitude, 24V

Allowable Output
Current at 24V

6A

5

4

3

2

1

0

-25 0 20 40

c

n

o

n

i

t

u

o

u

s

Ambient Temperature

60

s

h

r

o

t

t

e

r

m

70°

Allowable Output
Current at 24V

6A

5

4

3

2

1

0

The ambient temperature is defined 2cm below the unit.

Do not energize while condensation is present

IEC 60068-2-6

IEC 60068-2-27

temperature above 2000m sea level.

h

s

r

o

t

t

e

m

r

C

B

A

.

A

.

a

.

T

b

m

<

6

C

°

.

B

.

.

T

C

.

.

.

T

0 2000 4000

0

a

b

m

5

<

C

°

0

a

b

m

4

<

C

°

0

Altitude

6000m

July 08 / Rev. 1.2 DS-CD5.242-EN / All parameters are specified at 24V, 5A and 48Vdc input at 25°C ambient unless otherwise noted.

www.pulspower.com Phone [phone] Germany

11/21

CD–Series

DC/DC Converter; 24V, 5A

CD5.242

16. PROTECTION FEATURES

Output protection Electronically protected against overload, no-load and short-circuits
Output over-voltage protection typ. 31Vdc

max. 32Vdc

Reverse input polarity protection included Unit does not start when input voltage is reversed
Output over-current protection electronically limited See Fig. 7-1
Degree of protection IP 20 EN/IEC 60529
Penetration protection > 3.5mm E.g. screws, small parts
Over-temperature protection yes Output shut-down with automatic restart
Input transient protection MOV Metal Oxide Varistor
Internal input fuse T5A H.B.C. Not user replaceable

An audible noise may be heard during a no load, overload or short circuit event.

In case of an internal DC/DC converter fault, a redundant
circuit limits the maximum output voltage. The output
shuts down and automatically attempts to restart.

17. SAFETY

Input / output separation SELV IEC/EN 60950-1
PELV EN 60204-1, EN 50178, IEC 60364-4-41

Class of protection II PE (Protective Earth) connection not required
Isolation resistance > 5MOhm Input to output, 500Vdc
Chassis Ground resistance < 0.1Ohm Between housing and Chassis Ground terminal

Touch current (leakage current) The leakage current which is produced by the DC/DC converter itself depends on

Double or reinforced insulation,
Max. allowed voltage between any input pin and ground: 60Vdc or 42.4Vac

the input voltage ripple and need to be investigated in the final application.
For a smooth DC input voltage, the produced leakage current is less than 100µA.

18. DIELECTRIC STRENGTH

The output voltage is floating and has no ohmic connection to ground.
To fulfill the PELV requirements according to EN60204-1 § 6.4.1, it is recommend that either the + pole, the – pole or

any other part of the output circuit shall be connected to the protective earth system. This helps to avoid situations in
which a load starts unexpectedly or can not be switched off any more when an unnoticed earth faults occur.

Fig. 18-1 Dielectric strength

Input

+

-

A

Chassis
ground

B

C

Output

+

-

Type test 60s 1500Vac 1500Vac 500Vac

Factory test 5s 1500Vac 1500Vac 500Vac

Field test 5s 1000Vac 1000Vac 500Vac
Type tests and factory tests:

Conducted by the manufacturer. Do not repeat test in field!
Rules for field test:
Use appropriate test equipment which applies the voltage
with a slow ramp! Connect all input poles together as well
as all output poles.

A B C

July 08 / Rev. 1.2 DS-CD5.242-EN / All parameters are specified at 24V, 5A and 48Vdc input at 25°C ambient unless otherwise noted.

www.pulspower.com Phone [phone] Germany

12/21

CD–Series

DC/DC Converter; 24V, 5A

CD5.242

19. APPROVALS

IEC 60950-1

IECEE

CB SCHEME

UL 508

UL 60950-1

UL 1604

pending

The unit is suitable for use in Class I Division 2 Groups A, B, C, D locations as well as for Class I

CSA
pending

Marine

pending

Zone 2 Groups IIA, IIB and IIC locations. Substitution of components may impair suitability for
Class I Division 2 environment. Do not disconnect equipment unless power has been switched
off. Wiring must be in accordance with Class I, Division 2 wiring methods of the National
Electrical Code, NFPA 70, and in accordance with other local or national codes.

18WM

LISTED

IND. CONT. EQ.

R

CUS

182790

GL

ABS

CB Scheme,
Information Technology Equipment

LISTED E198865
Industrial Control Equipment

RECOGNIZED E137006 recognized for the use in U.S.A. (UL 60950-1)
and Canada (C22.2 No. 60950)
Information Technology Equipment, Level 3

RECOGNIZED E246877 recognized for use in U.S.A. (UL 1604) and
Canada (C22.2 No. 213-M1987)
Hazardous Location Class I Div 2 T4 Groups A,B,C,D and
Class I Zone 2 Groups IIA, IIB and IIC

CSA approval for Canada
CAN/CSA C22.2 No 107-1; CAN/ CSA 60950-1-03; UL60950-1

GL (Germanischer Lloyd) classified and ABS (American Bureau for
Shipping) PDA for marine and offshore applications.

Environmental category: C, EMC2

20. FULFILLED STANDARDS

EN 61558-2-17 Safety of Power Transformers

EN/IEC 60204-1 Safety of Electrical Equipment of Machines

EN/IEC 61131-2 Programmable Controllers

EN 50178, IEC 62103 Electronic Equipment in Power Installations

21. USED SUBSTANCES

The unit does not release any silicone and is suitable for the use in paint shops.

The unit conforms to the RoHS directive 2002/96/EC

Electrolytic capacitors included in this unit do not use electrolytes such as Quaternary Ammonium Salt Systems.

Plastic housings and other molded plastic materials are free of halogens, wires and cables are not PVC insulated.

The materials used in our production process do not include the following toxic chemicals:
Polychlorinated Biphenyl (PCB), Pentachlorophenol (PCP), Polychlorinated naphthalene (PCN), Polybrominated
Biphenyl (PBB), Polybrominated Biphenyl Oxide (PBO), Polybrominated Diphenyl Ether (PBDE), Polychlorinated
Diphenyl Ether (PCDE), Polybrominated Diphenyl Oxide (PBDO), Cadmium, Asbestos, Mercury, Silica

July 08 / Rev. 1.2 DS-CD5.242-EN / All parameters are specified at 24V, 5A and 48Vdc input at 25°C ambient unless otherwise noted.

www.pulspower.com Phone [phone] Germany

13/21

CD–Series

DC/DC Converter; 24V, 5A

CD5.242

22. PHYSICAL DIMENSIONS AND WEIGHT

Weight 425g / 0.94lb
DIN-Rail Use 35mm DIN-rails according to EN 60715 or EN 50022 with a height of 7.5 or 15mm.

The DIN-rail height must be added to the depth (102mm) to calculate the total required
installation depth.

Electronic files with mechanical data can be downloaded at www.pulspower.com

Fig. 22-1

Front view

Fig. 22-2

Side view

23. INSTALLATION AND OPERATION INSTRUCTIONS

Mounting:

Output terminal must be located on top and input terminal on the bottom. For other orientations see chapter 25.13.
An appropriate electrical and fire end-product enclosure should be considered in the end use application.

Cooling:

Convection cooled, no forced cooling required. Do not cover ventilation grill (e.g. cable conduits) by more than 30%!

Installation clearances:

40mm on top, 20mm on the bottom, 5mm on the left and right side are recommended when loaded permanently
with full power. In case the adjacent device is a heat source, 15mm clearance are recommended.

Risk of electrical shock, fire, personal injury or death!

Turn power off before working on the DC/DC converter. Protect against inadvertent re-powering.
Make sure the wiring is correct by following all local and national codes.
Do not open, modify or repair the unit.
Use caution to prevent any foreign objects from entering into the housing.
Do not use in wet locations or in areas where moisture or condensation can be expected.

Supplying source:

The inductance and resistance of the supplying network shall be below in Fig. 25-9 in chapter 25.10 to avoid resonant
effects on the input terminals. Please also check chapter 25.10.

Service parts:
The unit does not contain any service parts. The tripping of an internal fuse is caused by an internal fault. If damage
or malfunctioning should occur during operation, immediately turn power off and send unit to the factory for
inspection!

July 08 / Rev. 1.2 DS-CD5.242-EN / All parameters are specified at 24V, 5A and 48Vdc input at 25°C ambient unless otherwise noted.

www.pulspower.com Phone [phone] Germany

14/21

CD–Series

DC/DC Converter; 24V, 5A

CD5.242

24. ACCESSORY

ZM1.WALL Wall mounting bracket
This bracket is used to mount specific Dimension units onto a flat surface without utilizing a DIN-Rail. The two

aluminum brackets and the black plastic slide of the unit have to be removed, so that the two steel brackets can be
mounted.

(Please note: Picture shows a different unit)

Fig. 24-1 ZM1.WALL Wall Mounting Bracket Fig. 24-2 Assembled Wall Mounting Bracket

ZM11.SIDE Side mounting bracket
This bracket is used to mount specific Dimension units sideways with or without utilizing a DIN-Rail. The two

aluminum brackets and the black plastic slide of the unit have to be removed, so that the steel bracket can be
mounted.

For sideways DIN-rail mounting, the removed aluminum brackets and the black plastic slide need to be reinstalled on
the steel bracket.

(Please note: Pictures show a different unit)

Fig. 24-3 ZM11.SIDE Side Mounting Bracket Fig. 24-4 Side Mounting with DIN-rail brackets

July 08 / Rev. 1.2 DS-CD5.242-EN / All parameters are specified at 24V, 5A and 48Vdc input at 25°C ambient unless otherwise noted.

www.pulspower.com Phone [phone] Germany

15/21

CD–Series

DC/DC Converter; 24V, 5A

CD5.242

25. APPLICATION NOTES

25.1. PEAK CURRENT CAPABILITY

Solenoids, contactors and pneumatic modules often have a steady state (sealed) coil and a pick-up coil. The inrush
current demand of the pick-up coil is several times higher than the steady state current and usually exceeds the
nominal output current (including the PowerBoost) The same situation applies, when starting a capacitive load.

Branch circuits are often protected with circuit breakers or fuses. In case of a short or an overload in the branch
circuit, the fuse needs a certain amount of over-current to trip or to blow. The peak current capability ensures the
safe operation of subsequent circuit breakers.

Assuming the input voltage is turned on before such an event, the built-in large sized output capacitors inside the
DC/DC converter can deliver extra current. Discharging this capacitor causes a voltage dip on the output. The
following two examples show typical voltage dips:

Fig. 25-1 Peak load 10A for 50ms, typ. Fig. 25-2 Peak load 20A for 5ms, typ.

24V

Output
Voltage

24V

10A

0.7A

10ms/DIV

Peak load 10A (resistive) for 50ms

Output voltage dips from 24V to 17.1V.

17.1V

Output
Current

20A

0.7A
1ms/DIV

Peak load 20A (resistive) for 5ms

Output voltage dips from 24V to 11V.

Output
Voltage

11V

Output
Current

25.2. BACK-FEEDING LOADS

Loads such as decelerating motors and inductors can feed voltage back to the DC/DC converter. This feature is also
called return voltage immunity or resistance against Back- E.M.F. (E

This DC/DC converter is resistant and does not show malfunctioning when a load feeds back voltage to the DC/DC
converter. It does not matter, whether the DC/DC converter is on or off.

The maximum allowed feed back voltage is 30Vdc. The absorbing energy can be calculated according to the built-in
large sized output capacitor which is specified in chapter 7.

lectro Magnetic Force).

25.3. INDUCTIVE AND CAPACITIVE LOADS

The unit is designed to supply any kind of load, including unlimited capacitive and inductive loads.

July 08 / Rev. 1.2 DS-CD5.242-EN / All parameters are specified at 24V, 5A and 48Vdc input at 25°C ambient unless otherwise noted.

www.pulspower.com Phone [phone] Germany

16/21

CD–Series

DC/DC Converter; 24V, 5A

CD5.242

25.4. OUTPUT CIRCUIT BREAKERS

Standard miniature circuit breakers (MCBs or UL1077 circuit breakers) can be used for branch circuit protection.
Ensure that the MCB is also rated for DC voltage. The following tests show which circuit breakers the DC/DC converter
typically trips.

Circuit breakers have huge tolerances in their tripping behavior, therefore, these typical tests can only be used as a
recommendation or for comparing two different DC/DC converters. Furthermore, the loop impedance has a major
influence on whether a breaker trips or not. Two tests were performed, representing typical situations:

Test 1: Short circuit with S1 on the DC/DC converter end of the cable (loop impedance approx. 20mOhm)

Fig. 25-3 Branch protectors, test circuit 1

Circuit

Breaker

I

+

S1

-

+

Load

-

DC/DC

Converter

Input

DC

Test 2: Short circuit with S1 on the load end (additional impedance included; represents longer load wire length).

Fig. 25-4 Branch protectors, test circuit 2

Circuit

DC/DC

Converter

AC

DC

Breaker

I

+

-

R

+

S1 Load

-

*) A list of the circuit breakers under test is available on request.

Example:
Which wire gauge must be used to trip a C-Characteristic circuit breaker with a rating of 3A? The load wire length is
21m.

Answer: A 3A C-Characteristic circuit breaker requires a loop impedance of less than 270mOhm (test results). The wire
length table shows that up to 23m wire with a cross section of 1.5mm

2

1.5mm

shall be used.

180mOhm

270mOhm

Parameters:
Input voltage: 24Vdc, load current: 0A

The following circuit breaker tripped during the test:

A- or Z- Characteristic:: equal or smaller 8A *)
B- Characteristic: no tripping ≥ 6A *)

no breaker available < 6A
C- Characteristic: equal or smaller 3A *)

Parameters:
Input voltage: 24Vdc, load current: 0A

The following circuit breaker tripped during the test:

A- or Z- Characteristic:: ≤ 6A and R= 180mOhm *)
B- Characteristic: no tripping ≥ 6A *)

no breaker available < 6A
C- Characteristic: ≤ 3A and R= 270mOhm *)

What does this resistance mean in wire length?

2

0.5mm

0.7mm2 1.0mm2 1.5mm2 2.5mm2 4.0mm2

5.0m 7.0m 10m 15m 25m 40m

7.5m 10.5m 15m 23m 38m 60m

2

are below 270mOhm. A wire not smaller than

July 08 / Rev. 1.2 DS-CD5.242-EN / All parameters are specified at 24V, 5A and 48Vdc input at 25°C ambient unless otherwise noted.

www.pulspower.com Phone [phone] Germany

17/21

CD–Series

25.5. SERIES OPERATION

DC/DC converters can be connected in series to increase the output voltage.

Fig. 25-5 Schematic for series operation

Unit A

Input

Unit B

Input

Output

+

-

+

Output

-

+

Load

-

Earth
(see notes)

Instructions for use in series:

a) It is possible to connect as many units in series as needed,

providing the sum of the output does not exceed 150Vdc.

b) Voltages with a potential above 60Vdc are not SELV any more

and can be dangerous. Such voltages must be installed with a

protection against touching.
c) For serial operation use DC/DC converters of the same type.
d) Earthing of the output is required when the sum of the output

voltage is above 60Vdc.
e) Keep an installation clearance of 15mm (left/right) between

two DC/DC converters and avoid installing the DC/DC

converters on top of each other.
Note:

Avoid return voltage (e.g. from a decelerating motor or

battery) which is applied to the output terminals.

CD5.242

DC/DC Converter; 24V, 5A

25.6. PARALLEL USE TO INCREASE OUTPUT POWER

Several DC/DC converter can be paralleled to increase the output power.

Fig. 25-6 Schematic for parallel operation

Unit A

Input

Output

Unit B

Input

Output

Fuse

+

-

Fuse

+

-

*)

+

*)

Load

-

Instructions for parallel use:

a) Use only DC/DC converters from the same series (C-Series) or

consult PULS.
b) Adjust the output voltages of all power supplies to

approximately the same value (±200mV).
c) A fuse (or diode) on the output is only required if more than

three units are connected in parallel.
d) Do not load terminals with more than 25A. Follow wiring

instructions according to chapter 25.7
e) Ensure that the ambient temperature of the power supply does

not exceed 45°C.

25.7. DAISY CHAINING OF OUTPUTS

Daisy chaining (jumping from one power supply output to the next) is allowed as long as the maximum current
through one terminal pin does not exceed 25A. If the current is higher, use a separate distribution terminal block.

Fig. 25-7 Daisy chaining of outputs

max 25A!

Output

+ +

- -

DC/DC

Converter

Output

+ +

- -

DC/DC

Converter

+

Load

-

Fig. 25-8 Using distribution terminals

Output

+ +

- -

DC/DC

Converter

Output

+ +

- -

DC/DC

Converter

+

Load

-

Input

July 08 / Rev. 1.2 DS-CD5.242-EN / All parameters are specified at 24V, 5A and 48Vdc input at 25°C ambient unless otherwise noted.

Input

www.pulspower.com Phone [phone] Germany

Input

Input

Distribution
Terminals

18/21

CD–Series

DC/DC Converter; 24V, 5A

CD5.242

25.8. PARALLEL USE FOR 1+1 REDUNDANCY

DC/DC converters can be paralleled for 1+1 redundancy to gain a higher system availability. Redundant systems
require a certain amount of extra power to support the load in case one DC/DC converter unit fails. The simplest way
is to put two DC/DC converters in parallel. In case one converter fails, the other one is automatically able to support
the load current without any interruption.

Furthermore, redundant systems can be built by using a DC/DC converter powered from a battery and a power supply
with AC input.

- Use the decoupling module YR2.DIODE in combination with two CD5.241-S1 and use the DC-OK signals of the
DC/DC converter to monitor a faulty unit or input voltage.

- Use the redundancy module YRM2.DIODE in combination with two CD5.241 and use the DC-OK signals of the
redundancy module to monitor a faulty unit or input voltage.

Recommendations for building redundant power systems:
a) Use separate input fuses for each DC/DC converter.
b) Monitor the individual voltage sources of a redundant system. A DC-ok lamp and a DC-ok contact is included in

the redundancy module YRM2.DIODE and the DC/DC converter CD5.241-S1. This feature reports a faulty unit.

c) When possible, connect each DC/DC converter to different power sources.

25.9. CHARGING OF BATTERIES

The power supply can be used for float-charging of lead-acid or maintenance free 24V VRLA batteries.

Instructions for charging batteries:

a) Ensure that the ambient temperature of the power supply does not exceed 50°C.
b) Set the output voltage on a disconnected load, very precisely to the end-of-charge voltage according to the

expected battery temperature.

End-of-charge voltage 27.8V 27.5V 27.15V 26.8V
Battery temperature 10°C 20°C 30°C 40°C

c) Use a 6A or 10A circuit breaker (or blocking diode ) between the power supply and the battery.
d) Ensure that the output current of the power supply is below the allowed charging current of the battery.
e) Use only matched batteries when putting 12V types in series.
f) The return current to the power supply is typ. 26.4mA at 25Vdc when the power supply is switched off (except in

case a blocking diode is utilized).

July 08 / Rev. 1.2 DS-CD5.242-EN / All parameters are specified at 24V, 5A and 48Vdc input at 25°C ambient unless otherwise noted.

www.pulspower.com Phone [phone] Germany

19/21

CD–Series

DC/DC Converter; 24V, 5A

CD5.242

25.10. REQUIREMENTS FOR THE SUPPLYING SOURCE

In certain circumstances, the input filter of the DC/DC converter can show a resonant effect which is caused by the
supplying network. Especially when additional external input filters are utilized, a superimposed AC voltage can be
generated on the input terminals of the DC/DC converter which might cause a malfunction of the unit. Therefore,
additional input filters are not recommended. To avoid the resonant effects, the minimal resistance of the supplying
network which depends on the inductance of the input network, shall be above the boundary curve in Fig. 25-9.

Fig. 25-9 Requirements for an input filter

Resistance of the
supplying network

1 Ohm

100 mOhm

stability

10 mOhm

1 mOhm

0.1mH 1mH 10mH

Inductance of the supplying network

)

(

a

)

(

b

(a) max.
(b) typ.

25.11. EXTERNAL INPUT PROTECTION

The unit is tested and approved for branch circuits up to 50A. External protection is only required if the supplying
branch has an ampacity greater than this. In some countries local regulations might apply so check local codes and
local requirements.
If an external fuse is necessary or utilized, a minimum value is required to avoid undesired tripping of the fuse.

B-Characteristic C-Characteristic

Ampacity max.

min.

50A 50A

6A 6A

25.12. USE IN A TIGHTLY SEALED ENCLOSURE

When the DC/DC converter is installed in a tightly sealed enclosure, the temperature inside the enclosure will be
higher than the outside. The inside temperature defines the ambient temperature for the DC/DC converter.

Results from such an installation:
DC/DC converter is placed in the middle of the box, no other heat producing equipment inside the box
Enclosure: Rittal Type IP66 Box PK 9516 100, plastic, 110x180x165mm

Load: 24V, 4A; (=80%) load is placed outside the box
Input: 48Vdc
Temperature inside the box: 42.8°C
(in the middle of the right side of the DC/DC converter with a distance of 2cm)
Temperature outside the box: 24.0°C
Temperature rise: 28.8K

July 08 / Rev. 1.2 DS-CD5.242-EN / All parameters are specified at 24V, 5A and 48Vdc input at 25°C ambient unless otherwise noted.

www.pulspower.com Phone [phone] Germany

20/21

CD–Series

DC/DC Converter; 24V, 5A

CD5.242

25.13. MOUNTING ORIENTATIONS

Mounting orientations other than input terminals on the bottom and output on the top requires a reduction in
continuous output power or a limitation in the maximum allowed ambient temperature. The amount of reduction
influences the lifetime expectancy of the DC/DC converter. Therefore, two different derating curves for continuous
operation can be found below:

Curve A1 Recommended output current.
Curve A2 Max allowed output current (results approx. in half the lifetime expectancy of A1).

Fig. 25-10

Mounting
Orientation A

Standard
Orientation

Fig. 25-11

Mounting
Orientation B
(Upside down)

OUTPUT

DC/DC

Converter

INPUT

INPUT

Converter

DC/DC

OUTPUT

Fig. 25-12

Mounting
Orientation C

(Table-top
mounting)

Fig. 25-13

Mounting
Orientation D

(Horizontal cw)

Converter

INPUT

OUTPUT

DC/DC

Fig. 25-14

Mounting
Orientation E

(Horizontal ccw)

OUTPUT

DC/DC

INPUT

Converter

Output Current

6A

5
4
3
2
1

0

10 20 30

Output Current

6A

5
4
3
2
1

0

10 20 30

Output Current

6A

5
4
3
2
1

0

10 20 30

Output Current

6A

5
4
3
2
1

0

10 20 30

Output Current

6A

5
4
3
2
1

0

10 20 30

Ambient Temperature

40

50

Ambient Temperature

40

A

2

A

1

Ambient Temperature

40

A

2

A

1

Ambient Temperature

40

Ambient Temperature

40

50

50

50

50

A

1

60°C

A

2

A

1

60°C

60°C

60°C

A

2

A

1

60°C

July 08 / Rev. 1.2 DS-CD5.242-EN / All parameters are specified at 24V, 5A and 48Vdc input at 25°C ambient unless otherwise noted.

www.pulspower.com Phone [phone] Germany

21/21