Puls QTD20.241 Data Sheet

Q-Series

1. GENERAL DESCRIPTION

Modern machines typically use maintenance-free AC­motors which are controlled by frequency converters
or servo amplifiers. Such devices have an
intermediate DC-bus where all individual drives are
connected.
The QTD20 power supply can be connected directly
to the intermediate DC-bus. In case of a mains
failure, the QTD20 utilizes the kinetic energy from
the motor and the DC-bus capacitors to keep the
controls and other important peripheral equipment
operational until the motor is in a complete stop
position. With the QTD20 mains failure can be
handled with no problems.
Intermediate DC-buses are not usually filtered and
have high EMI noise superimposed. The QTD20 has a
very robust input stage and an appropriate input

filter included.

L1
L2
L3
PE

+

PE

f

f

QTD

+

-

PE

+

-

DC Load,
Controller

Additionally, the

Motor

QTD20 is UL 508
approved and is
equipped with

Motor

input fuses which
are rated and
tested for 600V
applications.

QTD20.241

24V, 20A, DC INPUT

POWER SUPPLY

• 600Vdc Input Voltage

• Optimized for Intermediate DC-busses of Drive Systems

• Two Input Fuses for 600Vdc Included

• Efficiency up to 95%

• Width only 65mm

• 125% Peak Load Capability

• Active Input Transient Filter

• Full Power Between -25°C and +60°C

• Minimal Inrush Current

• DC-OK Relay Contact

• Quick-connect Spring-clamp Terminals

• 3 Year Warranty

2. SHORT-FORM DATA

Output voltage DC 24V
Adjustment range 24-28V
Output current 20A continuous, 24V
25A for typ. 4s, 24V
Output power 480W continuous, 24V
600W for typ. 4s, 24V
Output ripple < 100mVpp 20Hz to 20MHz
Input voltage DC 600V
480-840Vdc continuous

Input current 0.85A 600Vdc, 24V, 20A
Inrush current typ. 1.5A peak
Efficiency 95.0% at 600Vdc
Losses 25.5W at 600Vdc
Temperature range -25°C to +70°C operational
Derating 12W/°C +60 to +70°C
Hold-up time typ. 22ms at 600Vdc
Dimensions 65x124x127mm wxhxd

360-480Vdc
840-900Vdc

< 1 minute
or with reduced
output current

3. ORDER NUMBERS

Power Supply
Accessory ZM1.WALL Wall mount bracket
ZM14.SIDE Side mount bracket
YR2.DIODE Decoupling module
UF20.241 Buffer unit

Jan. 2007 / Rev. 1.0 DS-QTD20.241-EN
All parameters are specified at 24V, 20A, 600Vdc input, 25°C ambient and after a 5 minutes run-in time unless otherwise noted.

QTD20.241

600VÆ24V Converter

www.pulspower.com Phone [phone] Germany

4. MARKINGS

LISTED

IND. CONT. EQ.

UL 508, pending

18WM

EMC, LVD

1/22

Q-Series

QTD20.241

24V, 20A, DC INPUT

INDEX PAGE INDEX PAGE

1.

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

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

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

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

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

6. Input Inrush Current ...........................................4

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

8. Hold-up Time.......................................................7

9. DC-OK Relay Contact ..........................................7

10. Efficiency and Power Losses................................8

11. Functional Diagram.............................................9

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

13. Terminals and Wiring........................................10

14. Reliability...........................................................10

15. EMC....................................................................11

16. Environment......................................................12

17. Protection Features ...........................................13

18. Safety .................................................................13

19. Dielectric Strength ............................................13

20. Approvals.......................................................... 14

21. Fulfilled Standards............................................ 14

22. Used Substances ............................................... 14

23. Physical Dimensions and Weight..................... 15

24. Installation and Operation Instructions .......... 15

25. Accessories ........................................................ 16

26. Application Notes............................................. 17

26.1. Repetitive Pulse Loading........................ 17

26.2. Back-feeding Loads................................ 18

Charging of Batteries....................................... 18

26.3. Output Circuit Breakers ......................... 19

26.4. Parallel Use to Increase Output Power . 20

26.5. Parallel Use for Redundancy.................. 20

26.6. Daisy Chaining of Outputs..................... 20

26.7. Series Operation..................................... 21

26.8. Inductive and Capacitive Loads ............. 21

26.9. Use in a Tightly Sealed Enclosure.......... 21

26.10. Mounting Orientations.......................... 22

INTENDED USE

The power supply shall only be installed and put into operation by qualified personnel.
This power supply 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 power supply 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 600V A figure displayed with the AC or DC before the value represents a nominal voltage with

standard tolerances (usually ±15%) included.
E.g.: DC 12V describes a 12V battery regardless whether it is charged (13.7V) or discharged
(10V)

600Vdc A figure with the unit (Vdc) at the end is a value which is used during testing without any

additional tolerances included.

DISCLAIMER

The information presented in this document is believed to be accurate and reliable and may change without notice.

Jan. 2007 / Rev. 1.0 DS-QTD20.241-EN
All parameters are specified at 24V, 20A, 600Vdc input, 25°C ambient and after a 5 minutes run-in time unless otherwise noted.

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2/22

Q-Series

QTD20.241

24V, 20A, DC INPUT

5. INPUT

Input
Input voltage range
360-480Vdc max. 60 seconds or with de-rating according to Fig. 7-2

Allowed voltage between input
and earth (ground)

max. ±900V peak value, allowed for transients

Slew rate for voltage between

input and earth (ground)
Allowed input ripple voltage max. 50Vpp 50Hz-40kHz
Turn-on voltage typ. 450Vdc Steady-state value, see Fig. 5-1
Shut-down voltage typ. 325Vdc Steady-state value, see Fig. 5-1
Input current
Start-up delay typ. 350ms See Fig. 5-2
Rise time typ. 70ms 0mF, 24V, 20A, see Fig. 5-2

Turn-on overshoot

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

Fig. 5-1 Input voltage range

nom. DC 600V
nom. 480-840Vdc continuous operation

840-900Vdc max. 60 seconds or with de-rating according to Fig. 7-2
1000Vdc Absolute maximum input voltage with no damage to the

power supply. Above 900Vdc, the output will switch off
and will turn-on again when the voltage falls below 850V.

max. 600V R.M.S. continuously allowed

max. 1000V/µs

typ. 0.85A At 600Vdc input, 24V, 20A, see Fig. 5-3

typ. 110ms 20mF, 24V, 20A, see Fig. 5-2
max. 500mV See Fig. 5-2

P

OUT

B A

B

A: continuously allowed

: < 60s or with derating

Shut-down

325Vdc

360Vdc

B

Turn-on

450Vdc

480Vdc

V

IN

900Vdc

840Vdc

Fig. 5-2 Turn-on behavior, definitions Fig. 5-3 Input current at 600Vdc vs. output load

Intput
Voltage

Output
Voltage

Jan. 2007 / Rev. 1.0 DS-QTD20.241-EN
All parameters are specified at 24V, 20A, 600Vdc input, 25°C ambient and after a 5 minutes run-in time unless otherwise noted.

- 5%

Start-up

delay

Rise

Time

Overshoot

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1.0A

0.8

0.6

0.4

0.2

0

2 4 6 8 10 12 14 16 18

Input Current, typ.

Output Current

20A

3/22

Q-Series

QTD20.241

24V, 20A, DC INPUT

6. INPUT INRUSH CURRENT

An active inrush limitation circuit limits the input inrush current after turn-on of the input voltage and after short

input voltage interruptions.

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

Inrush current max. 3A
typ. 1.5A
Inrush energy
Inrush delay

max. 1A2s -25°C to +70°C
typ. 350ms

Fig. 6-1 Input inrush current, typical behavior

Input Voltage

Output Voltage

A

Input Current

600Vdc

-25°C to +70°C

peak

-25°C to +70°C

peak

A: Inrush delay

Input: 600Vdc
Output: 24V, 20A
Ambient: 25°C

Upper curve: Input voltage 100V / DIV
Medium curve: Output voltage 5V / DIV
Lower curve: Input current 1A / DIV
Time basis: 100ms / DIV

Jan. 2007 / Rev. 1.0 DS-QTD20.241-EN
All parameters are specified at 24V, 20A, 600Vdc input, 25°C ambient and after a 5 minutes run-in time unless otherwise noted.

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4/22

Q-Series

QTD20.241

24V, 20A, DC INPUT

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 20A Æ 0A
Ripple and noise voltage

Output capacitance

Continuous output power capability

Output current

Output power

Short-circuit current min. 20A load impedance 50mOhm, see Fig. 7-1
max. 23A load impedance 50mOhm, see Fig. 7-1

nom. 24V
min. 24-28V guaranteed, multi turn potentiometer

max. 10mV 480Vdc Æ 840Vdc Æ 480Vdc, 24V, 20A

max. 100mVpp 20Hz to 20MHz, 50Ohm
typ. 1 000µF The energy of the bulk capacitor on the input side will be

nom. 20A at 24V see Fig. 7-1,

nom. 17.5A

nom. 480W at 24-28V, between 480Vdc and 840Vdc

24.1V

±0.2%, at full load, cold unit

transferred to the output to supply short load peaks.

Note: derating below 480Vdc and above 840Vdc, see Fig. 7-2
at 28V see

a derating is required below 480Vdc and above 840Vdc

Note: derating below 480Vdc and above 840Vdc, see

Fig. 7-1,

Fig. 7-2

BonusPower®, short term output power capability (up to typ. 4s)

The power supply is designed to support loads with a higher short-term power requirement without damage or

shutdown. The short-term duration is hardware controlled by an output power manager. The BonusPower

repeatedly available. Detailed information can be found in chapter 26.1 .

Once BonusPower® has been stopped by the output power limiter, a timer disables the next BonusPower® capability.

This timer (recovery time) will start as soon as the output voltage reaches the adjusted value again, which usually

happens after the load has been reduced.

Output current

Output power
Short-circuit current min. 25A load impedance 50mOhm, see Fig. 7-1
max. 28A load impedance 50mOhm, see Fig. 7-1
Bonus time
min 3.5s see Fig. 7-3

BonusPower® recovery time

nom. 25A at 24V, between 480Vdc and 840Vdc, see Fig. 7-1

Note: derating below 480Vdc and above 840Vdc, see

nom. 21.4A

nom. 600W 24-28V, short term

typ. 4s at 24V, > 25A, duration until the output voltage dips,

max. 4.5s
typ. 7s Overload free time to reset power manager, see Fig. 7-4

at 28V, between 480Vdc and 840Vdc, see
a derating is required below 480Vdc and above 840Vdc

Fig. 7-1

®

is

Fig. 7-2

Jan. 2007 / Rev. 1.0 DS-QTD20.241-EN
All parameters are specified at 24V, 20A, 600Vdc input, 25°C ambient and after a 5 minutes run-in time unless otherwise noted.

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5/22

Q-Series

QTD20.241

24V, 20A, DC INPUT

Fig. 7-1 Output voltage vs. output current, typ. Fig. 7-2 Output current vs. input voltage

Output Voltage

28V

24

20

16

12

8

4
0

Adjustment

Range

c
o

n
t

i

n
u
o
u
s

Output Current

0 5 10 20 25

15 30A

s
h

o
r

t

-

t
e

r
m

Allowed Output
Current at 24V

25A

20

<

0

15

6

10

5

0

360

480

Vdc

Vdc

s

f

o

r

t

y

.

p

s

4

c

o

n

t

i

u

n

u

o

Input Voltage

s

Fig. 7-3 Bonus time vs. output power

Bonus Time

5s

4

3

m

x

a

.

m

i

n

.

2

1

0

105 110 115 120 125

Output Power

130%

Fig. 7-4 BonusPower® recovery time

Limitation by

Power
Demand

<125%

Bonus

Time

Power Manager

Recovery Time

Bonus Power disabled

Output
Voltage

100%

Bonus Power

®

is available as soon as power comes on and immediately after the end of an output short circuit.

Fig. 7-5 BonusPower® after input turn-on

Fig. 7-6 BonusPower® after output short

6

<

840
Vdc

s

0

900
Vdc

100%

Short of

Output

125%

Bonus
Power

Intput
Voltage

Output
Voltage

100%

125%

Bonus

Power

Output
Voltage

Output
Power

Output
Power

Jan. 2007 / Rev. 1.0 DS-QTD20.241-EN
All parameters are specified at 24V, 20A, 600Vdc input, 25°C ambient and after a 5 minutes run-in time unless otherwise noted.

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6/22

Q-Series

QTD20.241

24V, 20A, DC INPUT

8. HOLD-UP TIME

600Vdc

Hold-up Time typ. 22ms 20A, 24V, see
typ. 44ms 10A, 24V, see Fig. 8-1

Fig. 8-1 Hold-up time vs. input voltage Fig. 8-2 Shut-down behavior, definitions

Hold-up Time

50ms

40

V,

4

2

V,

4

2

.

p

y

t

,

A

0

1

.

n

i

m

,

A

0

1

30

.

p

y

t

,

A

20

0

2

,

V

4

2

.

i

n

m

,

A

0

2

,

V

4

2

10

0

400 500 600 700 800Vdc

Input Voltage

Fig. 8-1

Intput
Voltage

Output
Voltage

Hold-up Time

- 5%

9. DC-OK RELAY CONTACT

This feature monitors the output voltage, which is produced by the power supply itself. It is independent of a back-

fed voltage from a unit which is connected in parallel to the power supply output.

Contact closes As soon as the output voltage reaches the adjusted output voltage.

Contact opens As soon as the output voltage dips more than 10% below the adjusted output voltage.

Contact re-closes As soon as the output voltage exceeds 90% of the adjusted voltage.

Contact ratings max 42.4Vdc 0.3A, 30Vdc 1A, 30Vac 0.5A resistive load

min 1mA at 5Vdc min. permissible load

Isolation voltage See dielectric strength table in section 19

Fig. 9-1 DC-ok relay contact behavior

V

=

V

OUT

ADJ

90%
V

ADJ

open

<

1ms

Short dips will be extended to a signal length of 250ms. Dips shorter than 1ms will be ignored.

Note:

The DC-ok feature requires that the output voltage

10%

reaches the nominal (=adjusted) level after turn-on in
order to function according to specification. If this level
cannot be achieved, the overload LED will be on and

>

1ms

250ms

the DC-ok contact will be open. The overload signal will
only shut off as soon as the adjusted voltage is reached.
This is an important condition to consider particularly, if
the load is a battery, the power supply is used in

openclosed closed

parallel or the power supply is used for N+1 redundant
systems.

Jan. 2007 / Rev. 1.0 DS-QTD20.241-EN
All parameters are specified at 24V, 20A, 600Vdc input, 25°C ambient and after a 5 minutes run-in time unless otherwise noted.

www.pulspower.com Phone [phone] Germany

7/22

A

A

c

c

Q-Series

QTD20.241

24V, 20A, DC INPUT

10. EFFICIENCY AND POWER LOSSES

600Vdc

Efficiency typ. 95.0% 20A, 24V,
Power losses typ. 25.5W 20A, 24V,
typ. 7.7W 0A

Fig. 10-1 Efficiency vs. output current at 24V Fig. 10-2 Losses vs. output current at 24V

Efficiency

96%

95
94
93
92
91
90
89
88

4 6 8 101214161820

Output Current

Fig. 10-3 Efficiency vs. input voltage, 24V, 20A Fig. 10-4 Losses vs. input voltage, 24V, 20A

Efficiency

95.5%

95.0

94.5

94.0

93.5

93.0

92.5
350 450 650 750 850

Input Voltage

550

Vd

Power Losses

30W

25

20

15

10

5

0

02468101214 20

Power Losses

35W

33.0

31.0

29.0

27.0

25.0

23.0
350 450 550 650 850

Output Current

Input Voltage

750

16 18

Vd

Jan. 2007 / Rev. 1.0 DS-QTD20.241-EN
All parameters are specified at 24V, 20A, 600Vdc input, 25°C ambient and after a 5 minutes run-in time unless otherwise noted.

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8/22

Q-Series

11. FUNCTIONAL DIAGRAM

Fig. 11-1 Functional diagram

+

-

Input
Fuses
(in + and ­pole)

Temper-

ature
Shut­down

Input Filter

Inrush Current

Limiter

Transient Filter

Output
Power

Manager

Output

Over-

Voltage

Protection

Power

Converter

Output
Voltage
Monitor

Output

Voltage

Regulator

Output

Filter

DC ok

Relay

QTD20.241

24V, 20A, DC INPUT

V

OUT

+
+

-

-

Over­load

DC
ok

DC
ok

12. FRONT SIDE AND USER ELEMENTS

Fig. 12-1 Front side

Output Terminals

Quick-connect spring-clamp
terminals, no tools required

+ Positive output

- Negative (return) output

Dual pins per pole
DC ok Relay contact
(NO-contact)

Input Terminals

Quick-connect spring-clamp
terminals, no tools required

+ - Power input

PE (Protective Earth) input

See chapter 13 “Terminals and
Wiring” to choose appropriate
wire gauges

Output voltage potentiometer
(multi turn potentiometer)
Open the flap to set the output voltage.
Factory setting: 24.1V

DC-ok LED (green)
Overload LED (red)

Normal mode OFF ON Closed
BonusPower®

mode
Overload

< 90%)

(V

OUT

Short-circuit

= ca. 0V)

(V

OUT

Over­temperature

No input power OFF OFF Open

Overload

LED

OFF ON Closed

ON OFF Open

ON OFF Open

ON OFF

DC-ok

LED

DC-ok

contact

Open

The DC-ok LED and the DC-ok contact
functions are synchronized

Jan. 2007 / Rev. 1.0 DS-QTD20.241-EN
All parameters are specified at 24V, 20A, 600Vdc input, 25°C ambient and after a 5 minutes run-in time unless otherwise noted.

www.pulspower.com Phone [phone] Germany

9/22

Q-Series

QTD20.241

24V, 20A, DC INPUT

13. TERMINALS AND WIRING

Type Bi-stable, quick-connect spring clamp terminals. IP20 Finger safe construction.

Suitable for field- and factory installation. Shipped in open position.
Solid wire 0.5-6mm
Stranded wire 0.5-4mm2
American wire gauge 20-10 AWG
Ferrules Allowed, but not required
Wire stripping length 10mm / 0.4inch
Pull-out force 10AWG:80N, 12AWG:60N, 14AWG:50N, 16AWG:40N (according to UL486E)

Fig. 13-1 Connecting a wire

1.

Insert the wire

To disconnect wire:
reverse the procedure

2.

Close the lever

2

Instructions:

a) Use appropriate copper cables that are designed

for an operating temperature of:
Input: 60°C for ambient up to 45°C and
75°C for ambient up to 60°C minimum.
Output: 75°C for ambient up to 40°C and
95°C for ambient up to 60°C minimum.

b) Follow local and national installation codes and

installation 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
(except PE wire).

e) Do not use the unit without PE connection.

14. RELIABILITY

Lifetime expectancy min. 42 000h 40°C, 24V, 20A
min. 77 500h 40°C, 24V, 10A
min. 119 000h 25°C, 24V, 20A
MTBF SN 29500, IEC 61709 t.b.d. 40°C, 24V, 20A
t.b.d. 25°C, 24V, 20A
MTBF MIL HDBK 217F t.b.d. 40°C, 24V, 20A, Ground Benign GB40
t.b.d. 25°C, 24V, 20A, Ground Benign GB25

The Lifetime expectancy shown in the table above 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 and 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.

Jan. 2007 / Rev. 1.0 DS-QTD20.241-EN
All parameters are specified at 24V, 20A, 600Vdc input, 25°C ambient and after a 5 minutes run-in time unless otherwise noted.

600Vdc

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10/22

Q-Series

QTD20.241

24V, 20A, DC INPUT

15. EMC

The power supply is suitable for applications in industrial environments without any restrictions. The CE mark is in
conformance with EMC guideline 89/336/EEC and 93/68/EEC and the low-voltage directive (LVD) 73/23/EEC. A detailed
EMC Report is available upon request

EMC Immunity

Electrostatic discharge EN 61000-4-2 Contact discharge

Electromagnetic RF field EN 61000-4-3 80MHz-1GHz 10V/m Criterion A

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

Surge voltage on input EN 61000-4-5 + Æ - 1000V Criterion A
Surge voltage on input EN 61000-4-5 + Æ PE, - Æ PE 4kV Criterion A

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

Conducted disturbance EN 61000-4-6 0.15-80MHz 10V Criterion A

Criteria:
A: Power supply shows normal operation behavior within the defined limits.

EMC Emission

Conducted emission EN 55011, EN 55022 N/A *)
Radiated emission EN 55011, EN 55022 Class A

*) There are no mandatory requirements in the generic standard EN 61000-6-4 for conducted emission on DC lines (input and
output). For the assessment of the conducted emission, the input filter of the frequency converter or servo amplifier need to be
taken into account.

Switching Frequencies

Switching frequency 1 100kHz Nearly constant
Switching frequency 2 30kHz to 90kHz Input voltage and load dependent
Switching frequency 3 17kHz to 120kHz Input voltage and load dependent

EN 61000-6-1, EN 61000-6-2, EN-61800-3

Air discharge

Output lines

+ / - Æ PE

EN 61000-6-4, EN-61800-3 Generic and product standards

The power supply has three converters with three different switching frequencies
included. One is nearly constant. The other two are input voltage and load dependent.

Generic and product standards
8kV

15kV

2kV
2kV

500V
500V

Criterion A
Criterion A

Criterion A
Criterion A

Criterion A
Criterion A

Jan. 2007 / Rev. 1.0 DS-QTD20.241-EN
All parameters are specified at 24V, 20A, 600Vdc input, 25°C ambient and after a 5 minutes run-in time unless otherwise noted.

www.pulspower.com Phone [phone] Germany

11/22

C

Q-Series

QTD20.241

24V, 20A, DC INPUT

16. ENVIRONMENT

Operational temperature -25°C to +70°C (-13°F to 158°F) Reduce output power above +60°C
Output de-rating 12W/°C 60-70°C (140°F to 158°F), see Fig. 16-1
Storage temperature -40 to +85°C (-40°F to 185°F) Storage and transportation

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

Vibration sinusoidal 2-17.8Hz: ±1.6mm;

17.8-500Hz: 2g
2 hours / axis

2(s3

Vibration random

0.5m
2 hours / axis

)

Shock 30g 6ms, 20g 11ms

3 bumps / direction,
18 bumps in total

Altitude 0 to 6000m (0 to 20 000ft) Reduce output power or ambient temperature

Output de-rating (for altitude) 30W/1000m or 5°C/1000m above 2000m, see Fig. 16-2
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. 16-1 Output current vs. ambient temp., Fig. 16-2 Output current vs. altitude

Allowed Output
Current at 24V

30A

25

20

15

10

5

0

-25 0 20 40

Ambient Temperature

f

r

o

t

y

p

4

.

s

c

o

i

t

n

u

n

u

o

s

70°

60

The ambient temperature is defined as the air temperature 2cm below the unit.

Do not energize while condensation is present
IEC 60068-2-6

IEC 60068-2-64

IEC 60068-2-27

above 2000m sea level.

Allowed Output
Current at 24V

30A

f

25

20

15

10

5

0

0 2000 4000

4

s

.

p

y

t

r

o

C

c

o

n

t

i

u

n

s

u

o

.

A

.

a

.

T

b

m

<

6

C

°

B

.

.

.

T

C

.

.

.

T

0

a

b

m

<

5

C

°

0

a

b

m

<

4

C

°

0

A

Altitude

B

6000m

Jan. 2007 / Rev. 1.0 DS-QTD20.241-EN
All parameters are specified at 24V, 20A, 600Vdc input, 25°C ambient and after a 5 minutes run-in time unless otherwise noted.

www.pulspower.com Phone [phone] Germany

12/22

Q-Series

QTD20.241

24V, 20A, DC INPUT

17. PROTECTION FEATURES

Output protection Electronically protected against overload, no load and short circuits *)
Output over-voltage protection typ. 32Vdc

max. 35Vdc

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) and active transient filter

Internal input fuse 5A, midget size

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

fast acting type
2 times

(+ line and - line)

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

The unit is equipped with two internal input fuses which
protect the unit against internal short circuits and ground
faults. The fuses are not user accessible. A tripping of an
internal fuse is caused by an internal fault.

18. SAFETY

Input / output separation SELV IEC/EN 60204-1
PELV EN 60204-1, EN 50178, IEC 60364-4-41
double or reinforced insulation
Class of protection I PE (Protective Earth) connection required
Isolation resistance > 5MOhm Input to output, 500Vdc
PE resistance < 0.1Ohm Between housing and PE terminal

Touch current (leakage current) The leakage current which is produced by the power supply itself depends on 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.

19. DIELECTRIC STRENGTH

Fig. 19-1 Dielectric strength

Input DC-ok

+

-

A

Earth

B

B

C

D

Output

+

-

Type test 60s 2500Vac 3000Vac 500Vac 500Vac

Factory test 5s 2500Vac 2500Vac 500Vac 500Vac

Field test 5s 2000Vac 2000Vac 500Vac 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 L1, L2 and L3 together as well as
all output poles.

A B C D

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

the – pole shall be connected to the protective earth system. This helps to avoid situations in which a load starts
unexpectedly or cannot be switched off when an unnoticed ground fault occurs.

Jan. 2007 / Rev. 1.0 DS-QTD20.241-EN
All parameters are specified at 24V, 20A, 600Vdc input, 25°C ambient and after a 5 minutes run-in time unless otherwise noted.

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13/22

Q-Series

24V, 20A, DC INPUT

20. APPROVALS

UL 508

pending

18WM

LISTED

IND. CONT. EQ.

LISTED E198865
Industrial Control Equipment

21. 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 for Use in Power Installations

EN 61800-5 Adjustable speed electrical power drive systems, Safety requirements

QTD20.241

22. USED SUBSTANCES

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

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), 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

Jan. 2007 / Rev. 1.0 DS-QTD20.241-EN
All parameters are specified at 24V, 20A, 600Vdc input, 25°C ambient and after a 5 minutes run-in time unless otherwise noted.

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14/22

Q-Series

QTD20.241

24V, 20A, DC INPUT

23. PHYSICAL DIMENSIONS AND WEIGHT

Weight 890g / 1.96lb
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 (127mm) to calculate the total required
installation depth.

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

Fig. 23-1 Front view Fig. 23-2 Side view

24. INSTALLATION AND OPERATION INSTRUCTIONS

Mounting and installation:

Output terminal must be located on top and input terminal on the bottom. For other orientations see section 26.10.
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. If the adjacent device is a heat source, 15mm clearance is recommended.

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

Do not use the unit without proper earth connection (Protective Earth). Use the pin on the terminal block for earth
connection and not one of the screws on the housing.
Turn power off before working on the power supply. 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.

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

Jan. 2007 / Rev. 1.0 DS-QTD20.241-EN
All parameters are specified at 24V, 20A, 600Vdc input, 25°C ambient and after a 5 minutes run-in time unless otherwise noted.

www.pulspower.com Phone [phone] Germany

15/22

Q-Series

QTD20.241

24V, 20A, DC INPUT

25. ACCESSORIES

ZM1.WALL Wall mounting bracket
This bracket is used to mount 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.

Fig. 25-1 ZM1.WALL Wall Mounting Bracket Fig. 25-2 Assembled Wall Mounting Bracket

ZM14.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 detached, so that the steel brackets can be
mounted.

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

Fig. 25-3 ZM14.SIDE Side Mounting Bracket

Panel Mount

Fig. 25-4 ZM14.SIDE Side Mounting Bracket

DIN-Rail Mount

Jan. 2007 / Rev. 1.0 DS-QTD20.241-EN
All parameters are specified at 24V, 20A, 600Vdc input, 25°C ambient and after a 5 minutes run-in time unless otherwise noted.

www.pulspower.com Phone [phone] Germany

16/22

Q-Series

QTD20.241

24V, 20A, DC INPUT

26. APPLICATION NOTES

26.1. REPETITIVE PULSE LOADING

Typically, a load current is not constant as it varies over time. For pulse load compatibility the following rules must be
met:

a) The pulse power demand must be below 125% of the nominal power.
b) The duration of the pulse power must be shorter than the allowed Bonus Time. (see output section)
c) The average (R.M.S.) output current must be below the specified continuous output current.

If the R.M.S. current is higher, the unit will respond with a thermal shut-down after a period of time. Use the

"Max. Duty Cycle Curve" (
d) The duty cycle must be below 0.75.
e) For altitudes higher than 2000m reduce the pulse loading (15W/1000m) or the ambient temperature (5°C/1000m)

Fig. 26-1 Repetitive pulse loads, definitions Fig. 26-2 Max. Duty Cycle Curve

P

max.

125%

100%

PEAKTPEAK

P

0

P

Base load (W)

0

Pulse load (above 100%)

P

PEAK

T

Duration between pulses (s)

0

T

Pulse duration (s)

PEAK

Utilizing the Max. Duty Cycle Curve:

Example to determine the repetition rate of pulses without dipping of the output voltage:

Parameters of application:

Pulse length of T

PEAK = 1s

Steady state load P
(= 50% of I

RATED

0=120W

)

Peak load P
(= 125% of I

PEAK = 600W

)

RATED

More examples for pulse load compatibility:

P

P

PEAK

T

0

PEAK

600W 480W 1s >25s 600W 240W 0.1s >0.16s
600W 0W 1s >1.3s 600W 240W 1s >1.6s
540W 240W 1s > 0,75s 600W 240W 3s >4.9s

Fig. 26-2) to check if the average output current is below the nominal current.

P

=

0

peak

1

0

P

=

5

0

P

=

7

0

0

%

)

T

0

Determining the repetition rate:

1) make a vertical line at P

Duty Cycle

0.75

0.6

0.4

0.2

0

D

utyCycle

T0 =

PEAK

P0

=

105 110 115 120

T

peak

=

T

peak + T0

T

peak -

(D

utyCycle

x T

D

utyCycle

= 125%

1

2) make a horizontal line where the vertical line crosses the P

3) Read the Max. Duty Cycle from the Duty Cycle-axis (= 0.37)

4) Calculate the min. pause (base load) length T

T

peak -

(D

utyCycle

x T

peak

)

T0 =

D

utyCycle

1s - (0.37 x 1s)

=

0.37

:

0

=1.7s

5) Pulse length = 1s, min. pause length = 1.7s

6) Max. repetition rate = pulse length +pause length = 2.7s

T0

P

P

PEAK

T

0

PEAK

T0

%

0
0

%
%

5

P

PEAK

125%100

= 50% curve

0

Jan. 2007 / Rev. 1.0 DS-QTD20.241-EN
All parameters are specified at 24V, 20A, 600Vdc input, 25°C ambient and after a 5 minutes run-in time unless otherwise noted.

www.pulspower.com Phone [phone] Germany

17/22

Q-Series

QTD20.241

24V, 20A, DC INPUT

26.2. BACK-FEEDING LOADS

Loads such as decelerating motors and inductors can feed voltage back to the power supply. This feature is also called
return voltage immunity or resistance against Back- E.M.F. (Electro Magnetic Force).

This power supply is resistant and does not show adverse effects when a load feeds back voltage to the power supply.
It does not matter, whether the power supply is on or off.

The maximum allowed feed back voltage is 34Vdc. The absorbing energy can be calculated according to the built-in
large sized output capacitor which is specified in chapter 7.

CHARGING OF BATTERIES

The power supply can be used to charge lead-acid or maintenance free batteries. (Two 12V batteries in series)

Instructions for charging batteries:

a) Set output voltage (measured at the battery) very precisely to the end-of-charge voltage.

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

b) Use a 25A circuit breaker (or blocking diode ) between the power supply and the battery.
c) Ensure that the output current of the power supply is below the allowed charging current of the battery.
d) Use only matched batteries when putting 12V types in series.
e) The return current to the power supply is typ. 16mA at 25Vdc when the power supply is switched off (except in

case a blocking diode is utilized).

Jan. 2007 / Rev. 1.0 DS-QTD20.241-EN
All parameters are specified at 24V, 20A, 600Vdc input, 25°C ambient and after a 5 minutes run-in time unless otherwise noted.

www.pulspower.com Phone [phone] Germany

18/22

Q-Series

QTD20.241

24V, 20A, DC INPUT

26.3. OUTPUT CIRCUIT BREAKERS

Standard miniature circuit breakers (MCBs or UL1077 circuit breakers) can be used for branch protection. Ensure that
the MCB is rated for DC voltage, too. The following tests show which circuit breakers the power supply 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 power supplies. 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 power supply end of the cable (loop impedance approx. 20mOhm)

Fig. 26-3 Branch protectors, test circuit 1

Circuit

Power

Supply

AC

DC

Breaker

I

+

S1

-

+

Load

-

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

Fig. 26-4 Branch protectors, test circuit 2

Circuit

Power

Supply

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 at a length of 15m before a B-Characteristic circuit breaker with 10A will trip?
Answer: A 10A B-Characteristic circuit breaker requires a loop impedance of less than 120mOhm based on the test

results. The wire length table shows that a length of 16.7m wire with a cross section of 2.5mm
120mOhm. A wire not smaller than 2.5mm

120mOhm
150mOhm

2

shall be used.

Parameters:
Input voltage: 600Vdc, load current: 0A

Tripping time shorter than 5s.
The following circuit breaker tripped during the test:

A- or Z- Characteristic:: equal or smaller 10A *)
B- Characteristic: equal or smaller 10A *)
C- Characteristic: equal or smaller 10A *)

Parameters:
Input voltage: 600Vdc, load current: 0A

Tripping time shorter than 5s.
The following circuit breaker tripped during the test:

A- or Z- Characteristic:: ≤ 10A and R< 120mOhm *)
B- Characteristic: ≤ 10A and R< 120mOhm *)
C- Characteristic: ≤ 8A and R<= 150mOhm *)

What does this resistance mean in wire length?

2

0.5mm

0.7mm2 1.0mm2 1.5mm2 2.5mm2 4.0mm2

3.3m 4.7m 6.7m 10.0m 16.7m 26.7m

4.2m 5.9m 8.4m 12.5m 20.9m 33.4m

2

is measured at

Jan. 2007 / Rev. 1.0 DS-QTD20.241-EN
All parameters are specified at 24V, 20A, 600Vdc input, 25°C ambient and after a 5 minutes run-in time unless otherwise noted.

www.pulspower.com Phone [phone] Germany

19/22

Q-Series

26.4. PARALLEL USE TO INCREASE OUTPUT POWER

Power supplies can be paralleled to increase the output power.

Fig. 26-5 Schematic for parallel operation

Unit A

Input

Output

Unit B

Input

Output

Fuse

+

-

Fuse

+

-

*)

+

*)

Load

-

Instructions for parallel use:

a) Use only power supplies from the same series (Q-Series).
b) Adjust the output voltages of all power supplies to

approximately the same value (±500mV).
Otherwise, the DC-ok signal might not work properly.

c) A fuse (or diode) on the output is only required if more

than three units are connected in parallel.

d) Keep an installation clearance of 15mm (left / right)

between two power supplies and avoid installing the
power supplies on top of each other.

26.5. PARALLEL USE FOR REDUNDANCY

QTD20.241

24V, 20A, DC INPUT

Power supplies can be paralleled for redundancy to gain a higher system availability. Redundant systems require a
certain amount of extra power to support the load in case one power supply unit fails. The simplest way is to put two
Q-Series power supplies in parallel. This is called a 1+1 redundancy. In case one power supply unit fails, the other one
is automatically able to support the load current without any interruption. Redundant systems for a higher power
demand are usually built in a N+1 method. E.g. Five power supplies, each rated for 10A are paralleled to build a 40A
redundant system.

Please note: This simple way to build a redundant system does not cover failures such as an internal short circuit on
the secondary side of the power supply. In such cases, the defect unit becomes a load for the other power supplies
and the output voltage can not be maintained any more. This can only be avoided by utilizing decoupling diodes
which are included in the decoupling module YR2.DIODE. (One module per power supply)

Recommendations for building redundant power systems:
a) Use separate input fuses for each power supply.
b) Monitor the individual power supply units. A DC-ok LED and a DC-ok contact is already included in the units This

feature reports a faulty unit.
c) When possible, connect each power supply to different phases or circuits.
d) It is desirable to set the output voltages of all power supplies to the same value to avoid a false DC-ok signal.

26.6. 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. 26-6 Daisy chaining of outputs

max 25A!

Fig. 26-7 Using distribution terminals

+

-

+ +

- -

Power

Supply

Input

Jan. 2007 / Rev. 1.0 DS-QTD20.241-EN
All parameters are specified at 24V, 20A, 600Vdc input, 25°C ambient and after a 5 minutes run-in time unless otherwise noted.

+ +

- -

Power

Supply

Input

+ +

Load

www.pulspower.com Phone [phone] Germany

- -

Power
Supply

Input

+ +

Power

Supply

- -

Input

+

Load

Distribution
Terminals

-

20/22

Q-Series

26.7. SERIES OPERATION

The power supply can be put in series to increase the output voltage.

Fig. 26-8 Schematic for series operation

Unit A

Input

Output

Unit B

Input

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 voltage does not exceed
150Vdc.

b) Voltages with a potential above 60Vdc are not considered

SELV any longer and can be dangerous. Such voltages must

be installed with a protection against touching.
c) For serial operation use power supplies 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 power supplies and avoid installing the power supplies

on top of each other.

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

Note:
battery) which is applied to the output terminals.

QTD20.241

24V, 20A, DC INPUT

26.8. INDUCTIVE AND CAPACITIVE LOADS

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

26.9. USE IN A TIGHTLY SEALED ENCLOSURE

When the power supply 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 power supply.

Results from such an installation:
Power supply is placed in the middle of the box, no other heat producing equipment inside the box
Enclosure: Rittal Typ IP66 Box PK 9519 100, plastic, 180x180x165mm

Load: 24V, 16A (=80% of the rated load); load is placed outside the box
Input: 600Vdc
Temperature inside enclosure: 54.9°C (in the middle of the right side of the power supply with a distance of 2cm)
Temperature outside enclosure: 22.6°C
Temperature rise: 32.3K

Jan. 2007 / Rev. 1.0 DS-QTD20.241-EN
All parameters are specified at 24V, 20A, 600Vdc input, 25°C ambient and after a 5 minutes run-in time unless otherwise noted.

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21/22

C

C

C

C

C

Q-Series

QTD20.241

24V, 20A, DC INPUT

26.10. 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 power supply. 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. 27-12

Mounting
Orientation A

Standard
Orientation

Fig. 27-13

Mounting
Orientation B
(Upside down)

OUTPUT

Power

Supply

INPUT

INPUT

Supply

Power

OUTPUT

Fig. 27-14

Mounting
Orientation C

(Table-top
mounting)

Fig. 27-15

Mounting
Orientation D

(Horizontal cw)

Supply

INPUT

OUTPUT

Power

Fig. 27-16

Mounting
Orientation E

(Horizontal ccw)

OUTPUT

Power

INPUT

Supply

Output Current

20A

16

12

8
4

0

Ambient Temperature

10 20 30 40

Output Current

20A

16

12

8
4

0

Ambient Temperature

10 20 30 40

Output Current

20A

16

12

8
4

0

Ambient Temperature

10 20 30 40

Output Current

20A

16

12

8
4

0

Ambient Temperature

10 20 30 40

Output Current

20A

16

12

8
4

0

Ambient Temperature

10 20 30 40

A

1

60°

50

A

2

A

1

50

A

2

A

1

50

A

2

A

1

50

A

2

A

1

50

60°

60°

60°

60°

Jan. 2007 / Rev. 1.0 DS-QTD20.241-EN
All parameters are specified at 24V, 20A, 600Vdc input, 25°C ambient and after a 5 minutes run-in time unless otherwise noted.

www.pulspower.com Phone [phone] Germany

22/22