QS40.481
48V, 20A, SINGLE PHASE INPUT

Q-Series

POWER SUPPLY
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AC 100-240V Wide-range Input
Width only 125mm, Weight only 1.9kg
95.0% Full Load and Excellent Partial Load Efficiencies
50% BonusPower, 1440W for up to 4s
55A High Peak Current for 10ms for Easy Fuse Tripping
Safe HiccupPLUS Overload Mode
Active PFC (Power Factor Correction)
Negligible Low Input Inrush Current Surge
Full Power Between -25°C and +60°C
Current Sharing Feature for Parallel Use
Internal Data Logging for Troubleshooting Included.
Remote Control of Output Voltage
DC-OK Relay Contact
Shut-down Input
ATEX and IECEx Approved
3 Year Warranty

PRODUCT DESCRIPTIONSHORT-FORM DATA

The most outstanding features of this Dimension QS40.481 DIN
rail power supply are the extremely high efficiency and the small
size, which are achieved by a synchronous rectification, abridgeless PFC circuit and additional unique design details.

Output voltage
Adjustment range
Output current

Large power reserves of 150% and built-in large sized output
capacitors support the starting of heavy loads such as DC motors
or capacitive loads. In many cases this allows the use of a unit
from a lower wattage class which saves space and money.

Output power

High immunity to transients and power surges as well as low
electromagnetic emissions makes usage in nearly every
environment possible.
The integrated input fuse as well as the near zero input inrush
current make installation and usage simple. Diagnostics are easy
due to the DC-OK relay, a green DC-OK LED and the red overloadLED.
A large international approval package for a variety of
applications makes this unit suitable for nearly every
application.

ORDER NUMBERS

Output ripple
Input voltage
Mains frequency
AC Input current
Power factor
AC Inrush current
Efficiency
LossesTemperature range
Derating
Hold-up time
Dimensions
WeightDC 48Vnominal48 - 54Vdc
20 – 17.8A
continuous
30 – 26.7A
short term (4s)960W
continuous
1440W
short term (4s)
< 150mVpp
20Hz to 20MHz
AC 100-240V-15%/+10%
50-60Hz±6%
8.6 / 4.5A
at 120 / 230Vac
0.99 / 0.99
at 120 / 230Vac
17 / 11A peakat 120 / 230Vac
93.9 / 95.0%
at 120 / 230Vac
62.4 / 50.5W
at 120 / 230Vac-25°C to +70°C
operational
24W/°C+60 to +70°C
between 85-90Vac see chapter 18
27 / 27ms
at 120 / 230Vac
125x124x127mm
WxHxD
1900g

MAIN APPROVALSPower Supply

QS40.481

48-54V Standard unit

Accessory

ZM2.WALL
UF20.481
YR40.482

Wall mount bracket
Buffer unit
Redundancy module

For details and the complete approval list, see chapter 22.

UL 508

UL 60950-1

Class I Div2

ATEX

IECEx

MarineJul. 2023 / Rev. 1.4 DS-QS40.481-EN
All parameters are specified at 48V, 20A, 230Vac, 25°C ambient and after a 5 minutes run-in time unless otherwise noted.
www.pulspower.com Phone +49 89 9278 0 Germany

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48V, 20A, SINGLE PHASE INPUT

Q-Series

INDEX
Page
1. Intended Use ................................................................ 3
2. Installation Instructions ................................................ 3
3. AC-Input ....................................................................... 5
4. Input Inrush Current ..................................................... 6
5. DC-Input ....................................................................... 6
6. Output .......................................................................... 7
7. Hold-up Time ................................................................ 9
8. DC-OK Relay Contact .................................................. 10
9. Shut-down Input ........................................................ 10
10. Remote Control of Output Voltage ............................ 11
11. Internal Data Logging ................................................. 11
12. Efficiency and Power Losses ....................................... 12
13. Lifetime Expectancy and MTBF .................................. 13
14. Functional Diagram .................................................... 13
15. Terminals and Wiring ................................................. 14
16. Front Side and User Elements .................................... 15
17. EMC ............................................................................ 16
18. Environment ............................................................... 17
19. Protection Features .................................................... 18
20. Safety Features........................................................... 18
21. Dielectric Strength ...................................................... 19
22. Approved, Fulfilled or Tested Standards .................... 20

Page
23. Regulatory Product Compliance ................................ 22
24. Physical Dimensions and Weight ............................... 23
25. Accessories................................................................. 24
25.1. ZM2.WALL - Wall mounting bracket ................ 24
25.2. UF20.481 - Buffer module ................................ 24
25.3. YR40.482 - Redundancy Module ...................... 25
26. Application Notes....................................................... 26
26.1. Repetitive Pulse Loading .................................. 26
26.2. Peak Current Capability .................................... 27
26.3. External Input Protection ................................. 27
26.4. Charging of Batteries ........................................ 28
26.5. Output Circuit Breakers .................................... 28
26.6. Parallel Use to Increase Output Power ............ 29
26.7. Parallel Use for Redundancy ............................ 29
26.8. Series Operation............................................... 30
26.9. Inductive and Capacitive Loads ........................ 30
26.10. Back-feeding Loads .......................................... 30
26.11. Operation on Two Phases ................................ 31
26.12. Use in a Tightly Sealed Enclosure ..................... 31
26.13. Mounting Orientations ..................................... 32

The information presented in this document is believed to be accurate and reliable and may change without notice.
No part of this document may be reproduced or utilized in any form without permission in writing from the publisher.

TERMINOLOGY AND ABREVIATIONSPE andsymbolPE 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.

AC 230V

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 disregarding whether it is full (13.7V) or flat (10V)

230VacA figure with the unit (Vac) at the end is a momentary figure without any additional tolerances included.

50Hz vs. 60Hz

As long as not otherwise stated, AC 230V parameters are valid at 50Hz mains frequency.

may

A key word indicating flexibility of choice with no implied preference.

shall

A key word indicating a mandatory requirement.

shouldA key word indicating flexibility of choice with a strongly preferred implementation.

Jul. 2023 / Rev. 1.4 DS-QS40.481-EN
All parameters are specified at 48V, 20A, 230Vac, 25°C ambient and after a 5 minutes run-in time unless otherwise noted.
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48V, 20A, SINGLE PHASE INPUT

Q-Series

1. INTENDED USEThis device is designed for installation in an enclosure and is intended for commercial use, such as in industrial control, process control,
monitoring and measurement equipment or the like.
Do not use this device in equipment, where malfunctioning may cause severe personal injury or threaten human life without additional
appropriate safety devices, that are suited for the end application.
If this device is used in a manner outside of its specification, the protection provided by the device may be impaired.

2. INSTALLATION INSTRUCTIONSWARNING

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

- Turn power off before working on the device and protect against inadvertent re-powering.
- Do not open, modify or repair the device.
- 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.
- Do not touch during power-on, and immediately after power-off. Hot surface may cause burns.
Obey the following installation instructions:This device may only be installed and put into operation by qualified personnel.
This device does not contain serviceable parts. The tripping of an internal fuse is caused by an internal defect.
If damage or malfunction should occur during installation or operation, immediately turn power off and send unit to the factory for
inspection.
Install device in an enclosure providing protection against electrical, mechanical and fire hazards.
Install the device onto a DIN rail according to EN 60715 with the input terminals on the bottom of the device. Other mounting
orientations require a reduction in output current.
Make sure that the wiring is correct by following all local and national codes. Use appropriate copper cables that are designed for aminimum operating temperature of 60°C for ambient temperatures up to +45°C, 75°C for ambient temperatures up to +60°C and 90°C
for ambient temperatures up to +70°C. Ensure that all strands of a stranded wire enter the terminal connection. Unused screw terminals
should be securely tightened. Use ferrules for wires on the input terminals.
The device is designed for pollution degree 2 areas in controlled environments. No condensation or frost is allowed.
The enclosure of the device provides a degree of protection of IP20. The enclosure does not provide protection against spilled liquids.
The device is designed for overvoltage category II zones.
The device is designed as “Class of Protection I” equipment according to IEC 61140. Do not use without a proper PE (Protective Earth)connection.
The device is suitable to be supplied from TN, TT or IT mains networks. The continuous voltage between the input terminal and the PE
potential must not exceed 276Vac.
A disconnecting means shall be provided for the input of the device.
The device is designed for convection cooling and does not require an external fan. Do not obstruct airflow and do not cover ventilation
grid!
The device is designed for altitudes up to 4000m. Above 2000m a reduction in output current is required.
Keep the following minimum installation clearances: 40mm on top, 20mm on the bottom, 5mm left and right side. Increase the 5mm to15mm in case the adjacent device is a heat source. When the device is permanently loaded with less than 50%, the 5mm can be reduced
to zero.
The device is designed, tested and approved for branch circuits up to 30A (UL) and 32A (IEC) without additional protection device. If an
external fuse is utilized, do not use circuit breakers smaller than 16A B- or C-Characteristic to avoid a nuisance tripping of the circuit
breaker.
Jul. 2023 / Rev. 1.4 DS-QS40.481-EN
All parameters are specified at 48V, 20A, 230Vac, 25°C ambient and after a 5 minutes run-in time unless otherwise noted.
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48V, 20A, SINGLE PHASE INPUT

Q-Series

The maximum surrounding air temperature is +70°C. The operational temperature is the same as the ambient or surrounding air
temperature and is defined 2cm below the device.
The device is designed to operate in areas between 5% and 95% relative humidity.
Installation Instructions for Hazardous Location Areas
The device is suitable for use in Class I Division 2 Groups A, B, C, D locations and for use in Group II
Category 3 (Zone 2) environments.
Classification: ATEX: EPS 14 ATEX 1 638 X, II 3G Ex ec nC IIC T3 Gc / IECEx EPS 14.0007X.
WARNING EXPLOSION HAZARDS!
Substitution of components may impair suitability for this environment. Do not disconnect the unit or operate the voltage adjustment or
S/P jumper unless power has been switched off or the area is known to be non-hazardous.
A suitable enclosure must be provided for the end product which has a minimum protection of IP54 and fulfils the requirements of the
EN 60079-0.

Jul. 2023 / Rev. 1.4 DS-QS40.481-EN
All parameters are specified at 48V, 20A, 230Vac, 25°C ambient and after a 5 minutes run-in time unless otherwise noted.
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48V, 20A, SINGLE PHASE INPUT

Q-Series

3. AC-INPUT
AC input
AC input rangenom.

AC 100-240V
90-264Vac
85-90Vac

suitable for TN, TT and IT mains networks

Allowed voltage L or N to earth
Input frequency
Turn-on voltage
Shut-down voltage
External input protection< 55°C ambient temperature continuously allowed> 55°C ambient temperature short term or with output derating
according Fig. 18-1
60-85Vacfull power for up to 200ms
0-85Vacno damage to the unit
264-300Vac< 500msmax.
300Vaccontinuous, IEC 62103
nom.
50–60Hz
±6%
typ.
80Vac
steady-state value, load independent, see Fig. 3-1
typ.
74Vac
steady-state value, load independent, see Fig. 3-1
See recommendations in chapter 26.3.

Input current
Power factor*)
Crest factor**)Start-up delay
Rise time

typ.
typ.
typ.
typ.
typ.

AC 100V
10.5A
0.99
1.47
800ms
16ms

AC 120V
8.6A
0.99
1.53
750ms
16ms

AC 230V
4.5A
0.99
1.56
700ms
16ms

typ.

55ms

55ms

55ms

max.

100mV

100mV

100mV

Turn-on overshootat 48V, 20A, see Fig. 3-3
at 48V, 20A, see Fig. 3-4
at 48V, 20A
see Fig. 3-2
at 48V, 20A, resistive load,
0mF see Fig. 3-2
at 48V, 20A, resistive load,
20mF see Fig. 3-2
see Fig. 3-2*) The power factor is the ratio of the true (or real) power to the apparent power in an AC circuit.
**) The crest factor is the mathematical ratio of the peak value to RMS value of the input current waveform.
Fig. 3-1 Input voltage range

Input
VoltageTurn-onShut -dow n

Rated input range- 5%

OutputVoltage

VIN
74 80 85

Start-up
delay

Fig. 3-3 Input current vs. output load at 48V

Fig. 3-4 Power factor vs. output load at 48VPower Factor, typ.

12A

1.0
A: 100Vac
B: 120Vac
C: 230Vac

8

Rise
Time

264VacInput Current, typ.

10

A

A

0.95

B

B

0.9

6
C

4

Output Current

2

4

6

8 10 12 14 16 18 20A

A: 100Vac
B: 120Vac
C: 230Vac

0.85
C

0.8

2
0

Overshoot

POUT

Fig. 3-2 Turn-on behavior, definitions

Output Current

0.75
2

4

6

8 10 12 14 16 18 20A

Jul. 2023 / Rev. 1.4 DS-QS40.481-EN
All parameters are specified at 48V, 20A, 230Vac, 25°C ambient and after a 5 minutes run-in time unless otherwise noted.
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48V, 20A, SINGLE PHASE INPUT

Q-Series

4. INPUT INRUSH CURRENT
The power supply is equipped with an active inrush current limitation circuit, which limits the input inrush current after turn-on to anegligible low value. The input current is usually smaller than the steady state input current.

Inrush current*)

Inrush energy
*)

max.

AC 100V
25Apeak

AC 120V
22ApeakAC 230V
16Apeak

typ.

20Apeak

17Apeak

11Apeak

max.

5A2s

5A2s

5A2s

over entire temperature range;
mains interruptions > 1s
over entire temperature range;
mains interruptions > 1s
over entire temperature range;
mains interruptions > 1s

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

Fig. 4-1 Typical turn-on behaviour at nominal load and
25°C ambient temperature

Input Current 5A / DIV

Input
230VacOutput

100mS/DIV

48Vdc

5. DC-INPUT
Do not operate this power supply with DC-input voltage. Check the CPS20.481-D1 unit instead. Two CPS20.241-D1 units in parallel might
be necessary.

Jul. 2023 / Rev. 1.4 DS-QS40.481-EN
All parameters are specified at 48V, 20A, 230Vac, 25°C ambient and after a 5 minutes run-in time unless otherwise noted.
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48V, 20A, SINGLE PHASE INPUT

Q-Series

6. OUTPUT
Output voltage
Adjustment range

max.
typ.
typ.
typ.
max.
max.
typ.

DC 48V
48-54Vdc
56Vdc****)
48.0Vdc
46.0Vdc
48.0Vdc
10mV
50mV
2000mV

max.
nom.
nom.
nom.

150mVpp
20A
17.8A
30A

nom.

26.7A

typ.

55A

Output power

nom.
nom.

960W
1440W*)

guaranteed
at clockwise end position of potentiometer±0.2%, at full load, cold unit, in “single use” mode
±0.5%, at full load, cold unit, in “parallel use” modeat no load, cold unit, in “parallel use” mode
85-300Vac
in “single use” mode: static value, 0A→20A, see Fig. 6-1
in “parallel use” mode: static value, 0A→20A,
see Fig. 6-2
20Hz to 20MHz, 50Ohm
continuously available at 48V, see Fig. 6-1 and Fig. 6-2
continuously available at 54V, see Fig. 6-1 and Fig. 6-2
short term available BonusPower*), at 48Vfor typical 4s, see Fig. 6-1 and Fig. 6-2
short term available BonusPower*), at 54Vfor typical 4s, see Fig. 6-1 and Fig. 6-2
up to 10ms, output voltage stays above 40V, see Fig. 6-4, This
peak current is available once every second.
See chapter 26.2 for more peak current measurements.
continuously available at 48-54V
short term available BonusPower*) at 48-54V

BonusPower time
BonusPower recovery time
Overload behavior

typ.
typ.

Short-circuit current

min.
max.
max.
typ.
typ.

4s
7s
cont. current
HiccupPLUS mode**)30A***)
35A***)
11.5A
62A
3 700µF

duration until the output voltage dips, see Fig. 6-5
overload free time to reset power manager, see Fig. 6-6
output voltage > 40Vdc, see Fig. 6-1
output voltage < 40Vdc, see Fig. 6-1
load impedance 50mOhm, see Fig. 6-3
load impedance 50mOhm, see Fig. 6-3
average (R.M.S.) current, load impedance 50mOhm, see Fig. 6-3
up to 10ms, load impedance <10mOhm, see Fig. 6-4
included in the power supply

Factory settingLine regulation
Load regulation

Ripple and noise voltage
Output current

Output capacitance
*)

**)

***)
****)

nom.

BonusPower, short term 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. This BonusPower is repeatedly available. Detailed information can be found in chapter 26.1. If thepower supply is loaded longer with the BonusPower than shown in the Bonus-time diagram (see Fig. 6-5), the max. output power is automatically reduced
to 960W. If the power requirement is continuously above 960W and the voltage falls below approx. 40V (due to the current regulating mode at overload),
the unit shuts-off and makes periodical restart attempts. This behavior is called hiccup mode which is described below. If the voltage is above 40V, the unit
continuously delivers current.
HiccupPLUS Mode
Up to 4s of overloading, the power supply delivers continuous output current. After this, the output power is reduced to nearly zero for approx. 17s before
a new start attempt is automatically performed. If the overload has been cleared, the device will operate normally. If the overload still exists, the output
current will be delivered for 2 to 4s (depending on the overload) again followed by a 17s rest time. This cycle is repeated as long as the overload exists. See
Fig. 6-3. During the off-period a small rest voltage and rest current is present on the output.
Discharge current of output capacitors is not included.
This is the maximum output voltage which can occur at the clockwise end position of the potentiometer due to tolerances. It is not guaranteed value
which can be achieved. The typical value is about 55V.

Jul. 2023 / Rev. 1.4 DS-QS40.481-EN
All parameters are specified at 48V, 20A, 230Vac, 25°C ambient and after a 5 minutes run-in time unless otherwise noted.
www.pulspower.com Phone +49 89 9278 0 Germany

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48V, 20A, SINGLE PHASE INPUT

Q-Series

Fig. 6-1 Output voltage vs. output current in “single use” mode,
typ.

Output Voltage

Fig. 6-2 Output voltage vs. output current in “paralleluse” mode, typ.

Output Voltage (Parallel Use, typ.)Adjustment Range

56V

56V
A

48

B
A

40

Adjustment Range

54V

B

52V

32

Continuously
allowed50V
A Continuously

24

available

B Short-term (4s)16then switching
to curve A

8
0
0

5

10

15

Bonus
Power

48V

Hiccupmode

Factory
setting

46V
44V
42V

20

25

30

0

35A

5

10

15

20

25

30A

Output Current

Output Current

Fig. 6-3 Short-circuit on output, HiccupPLUS mode, typ.

Fig. 6-4 Dynamic overcurrent capability, typ.

Output Voltage (dynamic behavior, <10ms)

54V

OutputCurrent
Normaloperation

Normaloperation

Short -circuit

35A

Adjustment
Range

48
40
32
24

t

0
2s

17s

2s

2s

17s

17s

16
8
0

Output Current

0Fig. 6-5 Bonus time vs. output power

10

20

30

40

50

60

70A

Fig. 6-6 BonusPower recovery time

Bonus Time

5s

Limitation by
Power Manager

Power
Demand

max.

4

100%

min.

3

t

2
OutputVoltage1

Recovery Time
Bonus Power disabled

Bonus
Time

Output Powert0
100 110 120 130 140 150 160 170%

The BonusPower is available as soon as power comes on and after the end of an output short circuit or output overload.
Fig. 6-7 BonusPower after input turn-on

Fig. 6-8 BonusPower after output short

Short ofOutput

Input
Voltage

OutputVoltage
OutputVoltage150%
Output
Power

100%

Bonus
Power

Output
Power

150%

Bonus
Power

100%

Jul. 2023 / Rev. 1.4 DS-QS40.481-EN
All parameters are specified at 48V, 20A, 230Vac, 25°C ambient and after a 5 minutes run-in time unless otherwise noted.
www.pulspower.com Phone +49 89 9278 0 Germany

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48V, 20A, SINGLE PHASE INPUT

Q-Series

7. HOLD-UP TIME
Hold-up TimeAC 100V
54ms
45ms
27ms
23ms

typ.
min.
typ.
min.

Fig. 7-1 Hold-up time vs. input voltage

AC 120V
54ms
45ms
27ms
23ms

AC 230V
54ms
45ms
27ms
23ms

at 48V, 10A, see Fig. 7-1
at 48V, 10A, see Fig. 7-1
at 48V, 20A, see Fig. 7-1
at 48V, 20A, see Fig. 7-1

Fig. 7-2 Shut-down behavior, definitions

Hold-up Time

Zero Transition

60ms

48V, 10A, typ.

50ms

48V, 10A, min.

Input
Voltage

40ms
30ms

48V, 20A, typ.

20ms

48V, 20A, min.

10ms
Input Voltage

0
90

120

155

190

- 5%

OutputVoltage
Hold-up Time

230VacJul. 2023 / Rev. 1.4 DS-QS40.481-EN
All parameters are specified at 48V, 20A, 230Vac, 25°C ambient and after a 5 minutes run-in time unless otherwise noted.
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48V, 20A, SINGLE PHASE INPUT

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8. 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 aunit connected in parallel to the power supply output.
Contact closes
Contact opens

As soon as the output voltage reaches 90% of the adjusted output voltage.
As soon as the output voltage dips more than 10% below the adjusted output voltage.
Short dips will be extended to a signal length of 250ms. Dips shorter than 1ms will be ignored.
As soon as the output voltage exceeds 90% of the adjusted voltage.
max.
60Vdc 0.3A, 30Vdc 1A, 30Vac 0.5A
resistive loadmin.
1mA at 5Vdc
min. permissible load
See dielectric strength table in chapter 21.

Contact re-closes
Contact ratings
Isolation voltage

Fig. 8-1 DC-OK relay contact behavior

VOUT = VADJ
10%

<
1ms

open

0.9* VADJ

>
1ms

250ms

closedopen

closed

9. SHUT-DOWN INPUTThis feature allows a switch-off of the output of the power supply with a signal switch or an external voltage. The shut-down occurs
immediately while the turn-on is delayed up to 350ms. In a shut-down condition, the output voltage is <4V and the output power is<0.5W.
The voltage between different minus pole output terminals must be below 1V when units are connected in parallel. In a series operationof multiple power supplies only wiring option “A” with individual signal switches is allowed.
Please note:- Option C requires a current sink capability of the voltage source. Do not use a blocking diode.
- The shut-down function has no safety feature included.
Fig. 9-1 Activation of the shut-down input

Option A:

Option B:
15 Shutdown
16 Input

OFF: linked
ON : open(via open
collector)n.c.
I

15 Shutdown
16 Input

Option C:(via external
voltagen.c.

15 Shutdown
16 Input+

OFF: I > 0.3mA
ON : I < 0.1mA-

U
OFF: U < 1V
ON : U = 4 -29V

Jul. 2023 / Rev. 1.4 DS-QS40.481-EN
All parameters are specified at 48V, 20A, 230Vac, 25°C ambient and after a 5 minutes run-in time unless otherwise noted.
www.pulspower.com Phone +49 89 9278 0 Germany

-

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48V, 20A, SINGLE PHASE INPUT

Q-Series

10. REMOTE CONTROL OF OUTPUT VOLTAGE
The shut-down input can also be used to remotely adjust the output voltage between typically 44Vdc and 54Vdc. All other functions of
shut-down input remain the same.
The control voltage is referenced to the main ground (negative output voltage)
Fig. 10-1 Remote control of the output voltage

Fig. 10-2 Applying the control voltage

Output Voltage

56V
52V
48V
44V
40V
36V
32V
28V
24V
0V

Potentiometer:
54V setting
48V setting

Control
Voltage+n.c.

15 Shutdown
16 Input

5V

10V

Control Voltage

Instructions:
1. Set the unit into “Single Use” mode
2. Set the output voltage adjustment (48-54V) to the maximum desired voltage.
3. Apply a control voltage to reduce the output voltage

11. INTERNAL DATA LOGGING
A protected microcontroller inside the power supply acquires and stores operating data during the life of the unit. The data can be
downloaded with a small tool and special software by the PULS service and repair personnel, even when the unit is defect. The data
allows for better troubleshooting. Analysis of what happened before a failure can be determined much more accurately.
Acquired data:- Family name of unit (QS40), revision of firmware- Operational hours- Expired portion of lifetime (combination of temperature and period of time)- Maximum ambient temperatures with timestamp (max. 47 values)- Maximal input voltages with timestamp (max. 47 values) and type of input voltage (AC or DC)- Failure report (various internal errors)- Number and timestamp of input overvoltage transients- Number and timestamp of over-temperature shut-downs- Number of turn-on sequences
The data will be acquired with a fixed sampling rate unless the peak detectors do trigger due to an abnormal condition. In such cases,
the abnormal condition will be captured. Furthermore, data will be acquired every time shortly before the unit switches off.

Jul. 2023 / Rev. 1.4 DS-QS40.481-EN
All parameters are specified at 48V, 20A, 230Vac, 25°C ambient and after a 5 minutes run-in time unless otherwise noted.
www.pulspower.com Phone +49 89 9278 0 Germany

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12. EFFICIENCY AND POWER LOSSES
Efficiency
Average efficiency*)

typ.
typ.

AC 100V
93.5%
92.9%

AC 120V
93.9%
93.3%

AC 230V
95.0%
93.9%

Power losses

typ.
typ.
typ.
typ.

3.6W
13.5W
35.6W
66.7W

3.5W
12.8W
34.0W
62.4W

3.3W
12.8W
30.1W
50.5W

*)

at 48V, 20A
25% at 5A, 25% at 10A, 25% at 15A.
25% at 20A
with activated shut-down
at 48V, 0A (no load)
at 48V, 10A (half load)
at 48V, 20A (full load)

The average efficiency is an assumption for a typical application where the power supply is loaded with 25% of the nominal load for 25% of the time, 50% of
the nominal load for another 25% of the time, 75% of the nominal load for another 25% of the time and with 100% of the nominal load for the rest of thetime.

Fig. 12-1 Efficiency vs. output current at 48V, typ.

Fig. 12-2 Losses vs. output current at 48V, typ.

Efficiency

Power Losses

96%
95
94
93
92
91
90
89
88

230Vac120Vac100VacOutput Current

4

6

8

80W
70
60
50
40
30
20
10
0

100Vac120Vac
230VacOutput Current

0

10 12 14 16 18 20A

2

4

6

8 10 12 14 16 16 20A

Fig. 12-3 Efficiency vs. input voltage at 48V, 20A, typ.

Fig. 12-4 Losses vs. input voltage at 48V, 20A, typ.

Efficiency

Power Losses

95%

80W

94

70

93

60

92

50

91

40
30

90
Input Voltage

89
85

120

155

190

Input Voltage

20
225 260Vac

85

120

155

Jul. 2023 / Rev. 1.4 DS-QS40.481-EN
All parameters are specified at 48V, 20A, 230Vac, 25°C ambient and after a 5 minutes run-in time unless otherwise noted.
www.pulspower.com Phone +49 89 9278 0 Germany190

225 260Vac

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13. LIFETIME EXPECTANCY AND MTBF
Calculated lifetime expectancy*)

MTBF**) SN 29500, IEC 61709
MTBF**) MIL HDBK 217F
Ground Benign

AC 100V
299 000h*)
106 000h
180 000h*)
64 000h
491 000h
274 000h
170 000h

AC 120V
305 000h*)
108 000h
193 000h*)
68 000h
481 000h
269 000h
171 000h

AC 230V
327 000h*)
116 000h
253 000h*)
90 000h537 000h
300 000h
183 000h

126 000h

127 000h

137 000h

36 000h36 000h

39 000h

27 000h

27 000h30 000h

MTBF**) MIL HDBK 217F
Ground Fixedat 48V, 10A and 25°C
at 48V, 10A and 40°C
at 48V, 20A and 25°C
at 48V, 20A and 40°C
at 48V, 20A and 25°C
at 48V, 20A and 40°C
at 48V, 20A and 25°C;
Ground Benign GB25
at 48V, 20A and 40°C;
Ground Benign GB40
at 48V, 20A and 25°C;
Ground Fixed GF25
at 48V, 20A and 40°C;
Ground Fixed GF40*)

The calculated lifetime expectancy shown in the table indicates the minimum operating hours (service life) and is determined by the lifetime expectancy ofthe built-in electrolytic capacitors. Lifetime expectancy is specified in operational hours and is calculated according to the capacitor’s manufacturer
specification. The manufacturer of the electrolytic capacitors only guarantees a maximum life of up to 15 years (131 400h). Any number exceeding this value
is a calculated theoretical lifetime which can be used to compare devices.
**) MTBF stands for Mean Time Between Failure, which is calculated according to statistical device failures, and indicates reliability of a device. It is the statisticalrepresentation of the likelihood of a unit to fail and does not necessarily represent the life of a product.
The MTBF figure is a statistical representation of the likelihood of a device to fail. A MTBF figure of e.g. 1 000 000h means that statistically one unit will failevery 100 hours if 10 000 units are installed in the field. However, it can not be determined if the failed unit has been running for 50 000h or only for 100h.

14. FUNCTIONAL DIAGRAM
Fig. 14-1 Functional diagram
Single /Parallel

OutputVoltage
Regulator

L
N

Input Fuse
Input Filter
Inrush Limiter

Temperature
Shutdown

Bridgeless
PFC
Converter

OutputPower
Manager

Event Datalogger

OutputOverVoltage
Protection

Power
Converter

OutputFilterVOUT++
Overload
LED
DC-ok
LED

OutputVoltage
Monitor

DCok
Relay

Shutdown

13
14

DC-ok
Contact

15 Shut-down
Input &
Remote16 Control

Jul. 2023 / Rev. 1.4 DS-QS40.481-EN
All parameters are specified at 48V, 20A, 230Vac, 25°C ambient and after a 5 minutes run-in time unless otherwise noted.
www.pulspower.com Phone +49 89 9278 0 Germany

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15. TERMINALS AND WIRING
The terminals are IP20 Finger safe constructed and suitable for field and factory wiring.
Type
Solid wire
Stranded wire
American Wire Gauge
Max. wire diameter
Wire stripping length
Screwdriver
Recommended tightening torqueInput
screw terminal
0.5-6mm2
0.5-4mm2
AWG 20-10
2.8mm(including ferrules)
7mm
3.5mm slotted or cross-head
No 2
1Nm

Outputscrew terminal
0.5-16mm2
0.5-10mm2
AWG 22-8
5.2mm(including ferrules)
12mm
3.5mm or 5mm slotted or
cross-head No 2
2.3Nm

DC-OK, Shut-down
spring-clamp terminal
0.15-1.5mm2
0.15-1.5mm2
AWG 26-14
1.5mm(including ferrules)
7mm
3mm slotted(to open the spring)Not applicable

Instructions:a) Use appropriate copper cables that are designed for minimum operating temperatures of:
60°C for ambient up to 45°C and
75°C for ambient up to 60°C minimum
90°C for ambient up to 70°C minimum.
b) Follow national installation codes and installation regulations!
c) Ensure that all strands of a stranded wire enter the terminal connection!
d) Do not use the unit without PE connection.
e) Unused terminal compartments should be securely tightened.
f) Ferrules are allowed.
Daisy chaining:
Daisy chaining (jumping from one power supply output to the next) is allowed as long as the average output current through one
terminal pin does not exceed 54A. If the current is higher, use a separate distribution terminal block as shown in Fig. 15-2.
Fig. 15-1 Daisy chaining of outputs

Fig. 15-2 Using distribution terminals

Distribution
Terminals

Power
SupplyPower
Supply+ + - -

+ + - -

Load

OutputOutput+-Power
SupplyPower
Supply+ + - -

+ + - -

Load

OutputOutput+-max 54A!

Jul. 2023 / Rev. 1.4 DS-QS40.481-EN
All parameters are specified at 48V, 20A, 230Vac, 25°C ambient and after a 5 minutes run-in time unless otherwise noted.
www.pulspower.com Phone +49 89 9278 0 Germany

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16. FRONT SIDE AND USER ELEMENTS
Fig. 16-1 Front side

A

B

C

D

E

F

G

H

Input Terminals (Screw terminals)
N, L Line input...PE (Protective Earth) input
Output Terminals (Screw terminals, two pins per pole)+
Positive output–
Negative (return) output“Parallel Use” “Single Use” Selector
Set jumper to “Parallel Use” when power supplies are connected inparallel to increase the output power. In order to achieve a sharing of
the load current between the individual power supplies, the “paralleluse” regulates the output voltage in such a manner that the voltage at
no load is approx. 4% higher than at nominal load. See also chapter
26.6. A missing jumper is equal to a “Single Use” mode.
Output Voltage Potentiometer
Multi turn potentiometer;
Open the flap to set the output voltage.
Factory set: 48.0V at full output current, “Single Use” mode.
DC-OK LED (green)
On, when the voltage on the output terminals is >90% of the adjusted
output voltage
Overload LED (red)- On, when the voltage on the output terminals is <90% of theadjusted output voltage, or in case of a short circuit in the output.
- Flashing, when the shut-down has been activated or the unit has
switched off due to over-temperature.
- Input voltage is required
DC-OK Relay Contact
The DC-OK relay contact is synchronized with the DC-OK LED.
See chapter 8 for details.
Shut-down and Remote Control Input
Allows the power supply to be shut down. Can be activated with aswitch contact or an external voltage.
The remote control input allows adjusting the output voltage between
44V and 54V. See chapter 9 and 10 for details.

Indicators, LEDs
Normal mode
During BonusPower
Overload (Hiccup mode)
Output short circuit
Temperature Shut-down
Active Shut-down input
No input power

Overload LED
OFFOFF
flashing
flashing
flashing
flashing
OFF

DC-OK LED
ON
ON
OFF
OFF
OFF
OFF
OFF

Jul. 2023 / Rev. 1.4 DS-QS40.481-EN
All parameters are specified at 48V, 20A, 230Vac, 25°C ambient and after a 5 minutes run-in time unless otherwise noted.
www.pulspower.com Phone +49 89 9278 0 Germany

DC-OK Contact
ClosedClosed
Open
Open
Open
Open
Open

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17. EMCThe power supply is suitable for applications in industrial environment as well as in residential, commercial and light industry
environment without any restrictions. A detailed EMC report is available on request.
EMC Immunity
Electrostatic discharge
Electromagnetic RF field
Fast transients (Burst)

Surge voltage on input
Surge voltage on output
Surge voltage on signal lines
Conducted disturbance
Mains voltage dips

Voltage interruptions
Voltage sags

Powerful transients

According generic standards: EN 61000-6-1 and EN 61000-6-2
EN 61000-4-2
contact discharge
8kV
Criterion A
air discharge
15kV
Criterion A
EN 61000-4-3
80MHz-2.7GHz
20V/m
Criterion A
EN 61000-4-4
input lines
4kV
Criterion A
output lines
2kV
Criterion A
signal lines (coupling clamp)
2kV
Criterion A
EN 61000-4-5
L→N
2kV
Criterion A
L → PE, N → PE
4kV
Criterion A
EN 61000-4-5+→1kV
Criterion A+ / - → PE
1kV
Criterion A
EN 61000-4-5
DC-OK signal → PE
1kV
Criterion A
EN 61000-4-5
Shut-down input → PE
not relevant due to wire length **)EN 61000-4-6
0.15-80MHz
20V
Criterion A
EN 61000-4-11
0% of 100Vac
0Vac, 20ms
Criterion A
40% of 100Vac
40Vac, 200ms
Criterion C
70% of 100Vac
70Vac, 500ms
Criterion A
0% of 200Vac
0Vac, 20ms
Criterion A
40% of 200Vac
80Vac, 200ms
Criterion A
70% of 200Vac
140Vac, 500ms
Criterion A
EN 61000-4-11
0% of 200Vac (=0V)
5000msCriterion C
SEMI F47
dips on the input voltage according to SEMI F47 standard
80% of 120Vac (96Vac)
1000msCriterion A
70% of 120Vac (84Vac)
500ms
Criterion A
50% of 120Vac (60Vac)
200ms
Criterion A
VDE 0160
over entire load range
750V, 1.3ms
Criterion B*)*) Criterion A is fulfilled for output current up to 15A.
**) Do not use longer wires than 30m for the shut-down input or use an additional protection.
Criterions:
A: Power supply shows normal operation behavior within the defined limits.
B: Output voltage will dip from 48V to 42V for 5ms
C: Temporary loss of function is possible. Power supply may shut-down and restarts by itself. No damage or hazards for the power supply will occur.

EMC Emission
Conducted emission
input lines

According generic standards: EN 61000-6-3 and EN 61000-6-4
EN 55011, EN 55032, FCC Part 15, CISPR 11,
Class BCISPR 32
Conducted emission
IEC/CISPR 16-1-2, IEC/CISPR 16-2-1
10dB higher than average limits for DC power
output lines
port according EN 61000-6-3***)
Radiated emission
EN 55011, EN 55032
Class B
Harmonic input current
EN 61000-3-2
fulfilled for class A equipment
Voltage fluctuations, flicker
EN 61000-3-3
fulfilled**)This device complies with FCC Part 15 rules.
Operation is subjected to 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.
**) Tested with constant current loads, non-pulsing***) Restrictions apply for applications in residential, commercial and light-industrial environments, where local DC power networks according to EN 61000-6-3 are
involved. No restrictions for all kinds of industrial applications.
Jul. 2023 / Rev. 1.4 DS-QS40.481-EN
All parameters are specified at 48V, 20A, 230Vac, 25°C ambient and after a 5 minutes run-in time unless otherwise noted.
www.pulspower.com Phone +49 89 9278 0 Germany

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Switching Frequencies

The power supply has four converters with four different switching frequencies included. One isnearly constant. The others are input voltage and load dependent.
105kHzResonant converter, nearly constant
1kHz to 150kHz
Boost converter, input voltage and load dependent
1kHz to 100kHzPFC converter, input voltage and load dependent
25kHz to 45kHz
Aux. converter, input voltage and load dependent

Switching frequency 1
Switching frequency 2
Switching frequency 3
Switching frequency 4

18. ENVIRONMENT
Operational temperature*)
Storage temperature
Output derating
Humidity**)Vibration sinusoidal-25°C to +70°C-40 to +85°C
24W/°C
5 to 95% r.H.
2-17.8Hz: ±1.6mm; 17.8-500Hz: 1g ***)
2 hours / axis
15g 6ms, 10g 11ms ***)
3 bumps / direction, 18 bumps in total
0 to 2000m
2000 to 6000m

Shock
Altitude

Altitude derating
Over-voltage category

reduce output power according Fig. 18-1
for storage and transportation
60-70°C
IEC 60068-2-30
IEC 60068-2-6
IEC 60068-2-27
without any restrictions
reduce output power or ambient temperature,
see Fig. 18-2
IEC 62103, EN 50178, overvoltage category II> 2000m, see Fig. 18-2
IEC 62103, EN 50178, altitudes up to 2000m
altitudes from 2000m to 6000m
IEC 62103, EN 50178, not conductive

60W/1000m or 5°C/1000m
III
II
2

Degree of pollution*) Operational temperature is the same as the ambient or surrounding temperature and is defined as the air temperature 2cm below the unit.
**) Do not energize while condensation is present.
***) Higher levels allowed when using the wall mounting bracket ZM2.WALL

Fig. 18-1 Output current vs. ambient temp.

Fig. 18-2 Output current vs. altitude

Allowed Output Current at 48V

Allowed Output Current at 48V

30A

30A

25
20
15

short-term (4s)A

20continuous

B

10

5
0
-25

continuous

15

A... 90-264Vac
B... 85-90Vac

10short-term (4s)

25

A... Tamb < 60°C
B... Tamb < 50°C
C... Tamb < 40°C

5
Ambient Temperature

0

20

40

A

0

2000

Jul. 2023 / Rev. 1.4 DS-QS40.481-EN
All parameters are specified at 48V, 20A, 230Vac, 25°C ambient and after a 5 minutes run-in time unless otherwise noted.
www.pulspower.com Phone +49 89 9278 0 Germany

C

Altitude0

60 70°C

B

4000

6000m

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19. PROTECTION FEATURES
Output protection
Output over-voltage protection

Degree of protection

Penetration protection
Over-temperature protection
Input transient protection
Internal input fuse*)

Electronically protected against overload, no-load and short-circuits*)
typ. 58.8Vdc
In case of an internal power supply defect, a redundant circuit
limits the maximum output voltage. The output shuts down andmax. 60Vdc
automatically attempts to restart.
IP 20
EN/IEC 60529
Caution: For use in a controlled environment according to CSA
22.2 No 107.1-01.
> 5mm
e.g. screws, small partsyes
Output shut-down with automatic restart
MOV (Metal Oxide Varistor)
included
not user replaceable

In case of a protection event, audible noise may occur.

20. SAFETY FEATURES
Input / output separation*)

Class of protection
Isolation resistancePE resistance
Touch current (leakage current)

*)

SELV
IEC/EN 60950-1
PELV
IEC/EN 60204-1, EN 50178, IEC 62103, IEC 60364-4-41
double or reinforced insulation
I
PE (Protective Earth) connection required> 100MOhm
input to output, 500Vdc< 0.1Ohm
typ. 0.39mA / 1.0mA
100Vac, 50Hz, TN-,TT-mains / IT-mains
typ. 0.56mA / 1.43mA
120Vac, 60Hz, TN-,TT-mains / IT-mains
typ. 0.90mA / 2.25mA
230Vac, 50Hz, TN-,TT-mains / IT-mains
max. 0.50mA / 1.21mA
110Vac, 50Hz, TN-,TT-mains / IT-mains
max. 0.71mA / 1.73mA
132Vac, 60Hz, TN-,TT-mains / IT-mains
max. 1.18mA / 2.82mA
264Vac, 50Hz, TN-,TT-mains / IT-mains

double or reinforced insulation

Jul. 2023 / Rev. 1.4 DS-QS40.481-EN
All parameters are specified at 48V, 20A, 230Vac, 25°C ambient and after a 5 minutes run-in time unless otherwise noted.
www.pulspower.com Phone +49 89 9278 0 Germany

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21. DIELECTRIC STRENGTH
The output voltage is floating and has no ohmic connection to the ground. Type and factory tests are conducted by the manufacturer.
Field tests may be conducted in the field using the appropriate test equipment which applies the voltage with a slow ramp (2s up and 2sdown). Connect all input-terminals together as well as all output poles before conducting the test. When testing, set the cut-off current
settings to the value in the table below.

Type test

60s

A
2500Vac

B
3000Vac

C
500VacD
500VacFactory test

5s

2500Vac

2500Vac

500Vac

500VacField test

5s

2000Vac

2000Vac

500Vac

500VacCut-off current setting> 20mA> 20mA> 40mA> 1mA

Fig. 21-1 Dielectric strength

Input
L
N

13
14

B

A

DC-ok
B* )

D
OutputEarth, PEC+/-

Shut-down
15/16

To fulfil the PELV requirements according to EN60204-1 § 6.4.1, werecommend 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
when unnoticed earth faults occur.

B*) When testing input to DC-OK ensure that the max. voltage between DC-OK and the output is not exceeded (column D). We recommend connecting DC-OK
pins and the output pins together when performing the test.

Jul. 2023 / Rev. 1.4 DS-QS40.481-EN
All parameters are specified at 48V, 20A, 230Vac, 25°C ambient and after a 5 minutes run-in time unless otherwise noted.
www.pulspower.com Phone +49 89 9278 0 Germany

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22. APPROVED, FULFILLED OR TESTED STANDARDSUL 508

IEC 61010-2-201

IEC 60950-1
UL 60950-1

ATEX

IECEx

Class I Div 2

Marine (DNV)

Marine (ABS)UL Certificate
Listed equipment for category NMTR - Industrial Control Equipment
Applicable for US and Canada
E-File: E198865
Manufacturer's Declaration
Electrical Equipment for Measurement, Control and Laboratory Use Particular requirements for control equipment
CB Scheme Certificate
General safety requirements for Information Technology Equipment (ITE)UL Certificate
Recognized component for category QQGQ - Information Technology
Equipment (ITE)
Applicable for US and Canada
E-File: E137006
Agency Certificate (Bureau Veritas)
EN 60079-0 Explosive atmospheres - General requirements
EN 60079-7, EN 60079-15 Equipment protection by typeof protection "e" and "n"Certificate: EPS 14 ATEX 1 638 X
Temperature Code: T3
Type of Protection: ec nC
IECEx Certificate
IEC 60079-0 Explosive atmospheres - General requirements
IEC 60079-7, IEC 60079-15 Equipment protection by typeof protection "e" and "n"Certificate: IECEx EPS 14.0007 X
Temperature Code: T3
Type of Protection: ec nC
CSA Certificate
Power Supplies for Hazardous Location
Applicable for Canada and US
CSA Class: 5318-01 (Canada), 5318-81 (USA)
Temperature Code: T3
Groups: A, B, C and D
DNV Certificate
DNV Type approved product
Certificate: TAA00002JT
Temperature: Class D
Humidity: Class B
Vibration: Class C
EMC: Class A
Enclosure: Class A
ABS Design Assessment Certificate
ABS (American Bureau of Shipment) assessed product
Certificate: 22-2231447-PDA

Jul. 2023 / Rev. 1.4 DS-QS40.481-EN
All parameters are specified at 48V, 20A, 230Vac, 25°C ambient and after a 5 minutes run-in time unless otherwise noted.
www.pulspower.com Phone +49 89 9278 0 Germany

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IEC 60068-2-60

ISA-71.04-1985

VDMA 24364

Manufacturer's Declaration (Online Document)
Environmental Tests, Flowing Mixed Gas Corrosion Test
Test Ke - Method 4
H2S: 10ppb
NO2: 200ppb
Cl2: 10ppb
SO2: 200ppb
Test Duration: 3 weeks, which simulates a service life of 10 years.
Manufacturer's Declaration (Online Document)
Airborne Contaminants Corrosion Test
Severity Level: G3 Harsh
H2S: 100ppb
NOx: 1250ppb
Cl2: 20ppb
SO2: 300ppb
Test Duration: 3 weeks, which simulates a service life of 10 years.
Paint Wetting Impairment Substances Test (or LABS-Test)
Tested for Zone 2 and test class C1 according to VDMA 24364-C1-L/W for
solvents and water-based paints

Jul. 2023 / Rev. 1.4 DS-QS40.481-EN
All parameters are specified at 48V, 20A, 230Vac, 25°C ambient and after a 5 minutes run-in time unless otherwise noted.
www.pulspower.com Phone +49 89 9278 0 Germany

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23. REGULATORY PRODUCT COMPLIANCE
EU Declaration of Conformity

REACH Regulation (EU)

WEEE Regulation

UKCA

CCC

KC

The CE mark indicates conformance with the European- EMC directive- ATEX directive- RoHS directive
Manufacturer's Declaration
EU regulation regarding the Registration, Evaluation, Authorisation andRestriction of Chemicals (REACH) fulfilled.
EU Regulation (EC) 1907/2006.
Manufacturer's Declaration
EU Regulation on Waste Electrical and Electronic Equipment
Registered as business to business (B2B) products.
EU Regulation 2012/19/EU
UKCA Declaration of Conformity
Trade conformity assessment for England, Scotland and WalesThe UKCA mark indicates conformity with the UK Statutory Instruments
2016 No.1107,
2016 No.1091,
2012 No.3032
CCC Certificate
China Compulsory Certification (CNCA-C23-01:2019)
Certificate for devices made in Suzhou/China (PULS Electronics):
2021122303114740
Certificate for devices made in Chomutov/Czech Republic (PULS investiční):2021122303114741
CCC-ExKC Korean Certification
Korean - Registration of Broadcasting and Communication Equipment
Registered under Clause3, Article 58-2 of Radio Waves Act.
Registration No. R-R-PUG-QS40_481.

Jul. 2023 / Rev. 1.4 DS-QS40.481-EN
All parameters are specified at 48V, 20A, 230Vac, 25°C ambient and after a 5 minutes run-in time unless otherwise noted.
www.pulspower.com Phone +49 89 9278 0 Germany

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24. PHYSICAL DIMENSIONS AND WEIGHT
Width
HeightDepth

WeightDIN rail
Housing material
Installation clearancesFig. 24-1 Front view

125mm
124mm
127mm
The DIN rail depth must be added to the unit depth to calculate the total required installation
depth.
1900g
Use 35mm DIN rails according to EN 60715 or EN 50022 with a height of 7.5 or 15mm.
Aluminium body, Steel coverSee chapter 2
Fig. 24-2 Side view

Jul. 2023 / Rev. 1.4 DS-QS40.481-EN
All parameters are specified at 48V, 20A, 230Vac, 25°C ambient and after a 5 minutes run-in time unless otherwise noted.
www.pulspower.com Phone +49 89 9278 0 Germany

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48V, 20A, SINGLE PHASE INPUT

Q-Series

25. ACCESSORIES
25.1. ZM2.WALL - WALL MOUNTING BRACKETThis bracket is used to mount specific DIMENSION units onto a flat surface without utilizing a DIN rail.

25.2. UF20.481 - BUFFER MODULE
This buffer unit is a supplementary device for DC 48V power supplies. It delivers power tobridge typical mains failures or extends the hold-up time after turn-off of the AC power. In
times when the power supply provides sufficient voltages, the buffer unit stores energy inintegrated electrolytic capacitors. In case of mains voltage fault, this energy is released again
in a regulated process.
The buffer unit does not require any control wiring. It can be added in parallel to the load
circuit at any given point. Buffer units can be added in parallel to increase the output ampacityor the hold-up time.

AC
DC

Jul. 2023 / Rev. 1.4 DS-QS40.481-EN
All parameters are specified at 48V, 20A, 230Vac, 25°C ambient and after a 5 minutes run-in time unless otherwise noted.
www.pulspower.com Phone +49 89 9278 0 Germany

Power
SupplyBufferUnit(s)

Load

+
-

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QS40.481
48V, 20A, SINGLE PHASE INPUT

Q-Series25.3. YR40.482 - REDUNDANCY MODULEThe YR40.482 is equipped with two input channels (20A each), which are individually
decoupled by utilizing mosfet technology. The output current can go as high as 40A.
Using mosfets instead of diodes reduces the heat generation and the voltage drop between
input and output.
The YR40.482 does not require an additional auxiliary voltage and is self-powered even in caseof a short circuit across the output.
Due to the low power losses, the unit is very slender and only requires 46mm width on the DIN
rail.

Fig. 25-1 Typical 1+1 Redundant configuration for 20A with a dual redundancy module
48V
20A
Load

QS40.481
48-54V 960W
Power Supply+

Single Use

ACInput

L N PEI

48V, 20A+ +QS40.481
48-54V 960W
Power Supply-

OutputDCOK

Parallel Use

FailureMonitor- -YR40.482
Redundancy
ModuleParallel Use

DCOKSingle Use

Input Input
12

ACInput+ - + -

L N PE

48V, 20A

+ +

- -

I

L
N
PE

Jul. 2023 / Rev. 1.4 DS-QS40.481-EN
All parameters are specified at 48V, 20A, 230Vac, 25°C ambient and after a 5 minutes run-in time unless otherwise noted.
www.pulspower.com Phone +49 89 9278 0 Germany

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QS40.481
48V, 20A, SINGLE PHASE INPUT

Q-Series

26. APPLICATION NOTES
26.1. REPETITIVE PULSE LOADING
Typically, a load current is not constant and varies over time. This power supply is designed to support loads with a higher short-term
power demand (=BonusPower). The short-term duration is hardware controlled by an output power manager and is available on arepeated basis. If the BonusPower load lasts longer than the hardware controller allows it, the output voltage will dip and the next
BonusPower is available after the BonusPower recovery time (see chapter 6) has elapsed.
To avoid this, the following rules must be met:a)
The power demand of the pulse must be below 150% of the nominal output power.
b)
The duration of the pulse power must be shorter than the allowed BonusPower time. (see output chapter)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 maximum duty cycle
curve (Fig. 26-2) to check if the average output current is below the nominal current.
d)
The duty cycle must be below 0.75.
Fig. 26-1 Repetitive pulse loads, definitions

Fig. 26-2 Max. duty cycle curve

P0 = 10%
P0 = 50%
P0 = 75%

Duty Cycle

PPEAK TPEAK

T0

0.75

max.
150%

0.6

100%

0.4

P0 = 100%

0.2

P0

PPEAK

0
100

P0
PPEAK
T0
TPEAK

Example:Base load (W)Pulse load (above 100%)
Duration between pulses (s)Pulse duration (s)110DutyCycle =

T0 =

120

130

140

150%

Tpeak
Tpeak + T0

Tpeak - (DutyCycle x Tpeak)
DutyCycle

A load is powered continuously with 480W (= 50% of the rated output load). From time to time a peak power of 1440W(= 150% of the rated output load) is needed for 1 second.
The question is: How often can this pulse be supplied without overloading the power supply?
- Make a vertical line at PPEAK = 150% and a horizontal line where the vertical line crosses the P0 = 50% curve. Read themax. duty cycle from the duty cycle-axis (= 0.37)- Calculate the required pause (base load) length T0:- Result: The required pause length = 1.7s

T0=

Tpeak - (DutyCycle x Tpeak)- Max. repetition rate = pulse +pause length = 2.7s

DutyCycle=

1s- (0.37 x 1s)
0.37

=1.7s

More examples for pulse load compatibility:
PPEAK
1440W
1440W
1200W

P0
960W
0W
480W

TPEAK
1s
1s
1s

T0
>25s
>1.3s
> 0.75s

PPEAK
1440W
1440W
1440W

P0
480W
480W
480W

TPEAK
0.1s
1s
3s

T0
>0.16s>1.6s>4.9s

Jul. 2023 / Rev. 1.4 DS-QS40.481-EN
All parameters are specified at 48V, 20A, 230Vac, 25°C ambient and after a 5 minutes run-in time unless otherwise noted.
www.pulspower.com Phone +49 89 9278 0 Germany

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QS40.481
48V, 20A, SINGLE PHASE INPUT

Q-Series

26.2. PEAK CURRENT CAPABILITY
The power supply can deliver peak currents (up to several milliseconds) which are higher than the specified short term currents.
This helps to start current demanding loads. Solenoids, contactors and pneumatic modules often have a steady state 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 BonusPower). The same situation applies when starting a capacitive load.
The peak current capability also ensures the safe operation of subsequent circuit breakers of load circuits. The load branches are often
individually protected with circuit breakers or fuses. In case of a short or an overload in one branch circuit, the fuse or circuit breakerneed a certain amount of over-current to open in a timely manner. This avoids voltage loss in adjacent circuits.
The extra current (peak current) is supplied by the power converter and the built-in large sized output capacitors of the power supply.
The capacitors get discharged during such an event, which causes a voltage dip on the output. The following two examples show typicalvoltage dips:
Fig. 26-3 Peak load with 2x the nominal current for 50ms,
typ.

OutputVoltage

48V
40A

Fig. 26-4 Peak load with 5x the nominal current for 5ms,
typ.

OutputVoltage

48V

37.9V

28.9V

100A
0A

OutputCurrent
10ms/DIV

40A Peak load (resistive) for 50ms
Output voltage dips from 48V to 37.9V.

0A

1ms/DIV

OutputCurrent

100A Peak load (resistive) for 5ms
Output voltage dips from 48V to 28.9V.

Please note: The DC-OK relay triggers when the voltage dips more than 10% for longer than 1ms.

Peak current voltage dips

typ.
typ.
typ.

from 48V to 37.9V
from 48V to 34.9V
from 48V to 28.9V

at 40A for 50ms, resistive load
at 100A for 2ms, resistive load
at 100A for 5ms, resistive load

26.3. EXTERNAL INPUT PROTECTION
The unit is tested and approved for branch circuits up to 30A (U.S.A.) and 32A (IEC). An external protection is only required if the
supplying branch has an ampacity greater than this. Check also local codes and local requirements. In some countries local regulations
might apply.
If an external fuse is necessary or utilized, minimum requirements need to be considered to avoid nuisance tripping of the circuit
breaker. A minimum value of 16A B- or C-Characteristic breaker should be chosen, when the unit is used at AC100 and AC120V mains
voltages (including AC 230V). If the unit is used only at AC 230V mains, a 10A B- or C-Characteristic breaker is sufficient.

Jul. 2023 / Rev. 1.4 DS-QS40.481-EN
All parameters are specified at 48V, 20A, 230Vac, 25°C ambient and after a 5 minutes run-in time unless otherwise noted.
www.pulspower.com Phone +49 89 9278 0 Germany

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QS40.481
48V, 20A, SINGLE PHASE INPUT

Q-Series

26.4. CHARGING OF BATTERIESThis power supply is not recommended to charge lead-acid or maintenance free batteries. The recommended end-of-charge voltage of
55.0V (at 20°C) for four 12V VRLA lead-acid batteries in series can not be supplied from the QS40.481 unit.

26.5. OUTPUT CIRCUIT BREAKERS
Standard miniature circuit breakers (MCB’s or UL1077 circuit breakers) are commonly used for AC-supply systems and may also be usedon DC branches.
MCB’s are designed to protect wires and circuits. If the ampere value and the characteristics of the MCB are adapted to the wire sizethat is used, the wiring is considered as thermally safe regardless of whether the MCB opens or not.
To avoid voltage dips and under-voltage situations in adjacent 48V branches which are supplied by the same source, a fast (magnetic)
tripping of the MCB is desired. A quick shutdown within 10ms is necessary corresponding roughly to the ride-through time of PLC's. Thisrequires power supplies with high current reserves and large output capacitors. Furthermore, the impedance of the faulty branch mustbe sufficiently small in order for the current to actually flow. The best current reserve in the power supply does not help if Ohm’s law
does not permit current flow. The following table has typical test results showing which B- and C-Characteristic MCBs magnetically trip
depending on the wire cross section and wire length.
Fig. 26-5 Test circuit

Power Supply

AC

MCB

+

+
Wire length

DC S1... Fault simulation switch

*)

Load

S1

-

Maximal wire length*) for a fast (magnetic) tripping:
0.75mm²
1.0mm²1.5mm²
C-2A
68m
89m
>100m
C-3A
53m
75m
>100m

2.5mm²
>100m
>100m

C-4A
C-6A
C-8A

44m
18m
9m

57m
25m
12m

88m
38m
18m

>100m
58m
24m

C-10A
C-13A

8m
4m

11m
5m

16m
8m

23m
12m

B-6A
B-10A
B-13A

39m
21m
13m

50m
29m
21m

74m
44m
34m

>100m
68m
52m

B-16A
B-20A

7m
2m

9m
3m

13m
4m

17m
5m

Don’t forget to consider twice the distance to the load (or cable length) when calculating the total wire length (+ and – wire).

Jul. 2023 / Rev. 1.4 DS-QS40.481-EN
All parameters are specified at 48V, 20A, 230Vac, 25°C ambient and after a 5 minutes run-in time unless otherwise noted.
www.pulspower.com Phone +49 89 9278 0 Germany

28/32

QS40.481
48V, 20A, SINGLE PHASE INPUT

Q-Series

26.6. PARALLEL USE TO INCREASE OUTPUT POWER
Power supplies from the same series (Q-Series) can be paralleled to increase the output
power. The output voltage shall be adjusted to the same value (±100mV) in “Single use”
mode with the same load conditions on all units, or the units can be left with the factory
settings. After the adjustments, the jumper on the front of the unit shall be moved from“Single use” to “Parallel use”, in order to achieve load sharing. The “Parallel use” mode
regulates the output voltage in such a manner that the voltage at no load is approx. 4%
higher than at nominal load. See also chapter 6. If no jumper is plugged in, the unit is in“Single use” mode. Factory setting is also “Single use” mode.
If more than three units are connected in parallel, a fuse or circuit breaker with a rating of
30A or 32A is required on each output. Alternatively, a diode or redundancy module canalso be utilized.

Unit A

AC

+
-

DC

+

Unit B

AC

DC

Load

+
-

-

Energize all units at the same time to avoid the overload HiccupPLUS mode. It also might be necessary to cycle the input power (turn-off
for at least five seconds), if the output was in HiccupPLUS mode due to overload or short circuits and the required output current is higher
than the current of one unit.
Keep an installation clearance of 15mm (left / right) between two power supplies and avoid installing the power supplies on top of eachother. Do not use power supplies in parallel in mounting orientations other than the standard mounting orientation (terminals on thebottom of the unit) or in any other condition where a derating of the output current is required (e.g. altitude, above 60°C, …).
Pay attention that leakage current, EMI, inrush current, harmonics will increase when using multiple power supplies.

26.7. PARALLEL USE FOR REDUNDANCYPower supplies can be paralleled for redundancy to gain 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 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
20A are paralleled to build a 80A redundant system. For N+1 redundancy the same restrictions apply as for increasing the output power,
see also chapter 26.6.
Please note: This simple way to build a redundant system does not cover failures such as an internal short circuit in the secondary sideof the power supply. In such a case, the defective unit becomes a load for the other power supplies and the output voltage can not be
maintained any more. This can be avoided by utilizing redundancy modules, which have decoupling devices (diodes or mosfets)
included. Further information and wiring configurations can be found in chapter 25.3.
Recommendations for building redundant power systems:
a)
b)
c)
d)

Use separate input fuses for each power supply. A separate source for each supply when possible increases the reliability of theredundant system.
Set the power supply into “Parallel Use” mode.
Monitor the individual power supply units. Therefore, use the DC-OK relay contact of the QS40 power supply.
It is desirable to set the output voltages of all units to the same value (± 100mV) or leave it at the factory setting.

Jul. 2023 / Rev. 1.4 DS-QS40.481-EN
All parameters are specified at 48V, 20A, 230Vac, 25°C ambient and after a 5 minutes run-in time unless otherwise noted.
www.pulspower.com Phone +49 89 9278 0 Germany

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QS40.481
48V, 20A, SINGLE PHASE INPUT

Q-Series

26.8. SERIES OPERATION

Unit A

Power supplies of the same type can be connected in series for higher output voltages.
It is possible to connect as many units in series as needed, providing the sum of theoutput voltage does not exceed 150Vdc. 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.

AC

Earthing of the output is required when the sum of the output voltage is above 60Vdc.

AC

Avoid return voltage (e.g. from a decelerating motor or battery) which is applied to the
output terminals.

DC

+
+

Unit B

DC

Load

+
-

Earth
(see notes)

Keep an installation clearance of 15mm (left / right) between two power supplies andavoid installing the power supplies on top of each other. Do not use power supplies in series in mounting orientations other than thestandard mounting orientation (terminals on the bottom of the unit).
Pay attention that leakage current, EMI, inrush current, harmonics will increase when using multiple power supplies.

26.9. INDUCTIVE AND CAPACITIVE LOADSThe unit is designed to supply any kind of loads, including capacitive and inductive loads. If extreme large capacitors, such as EDLCs(electric double layer capacitors or “UltraCaps”) with a capacitance > 1F are connected to the output, the unit might charge thecapacitor in the HiccupPLUS mode (see chapter 6).

26.10. 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 malfunctioning 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 63Vdc. The absorbing energy can be calculated according to the built-in large sized output
capacitor which is specified in chapter 6.

Jul. 2023 / Rev. 1.4 DS-QS40.481-EN
All parameters are specified at 48V, 20A, 230Vac, 25°C ambient and after a 5 minutes run-in time unless otherwise noted.
www.pulspower.com Phone +49 89 9278 0 Germany

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QS40.481
48V, 20A, SINGLE PHASE INPUT

Q-Series

26.11. OPERATION ON TWO PHASESPower Supply
240V +10% max.

L1

The power supply can also be used on two-phases of a three-phase-system. Such aphase to phase connection is allowed as long as the supplying voltage is below 240V+10%.
L3

L2

AC
L

internal
fuse

N
PE
DC

26.12. 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 outside. In
such situations, the inside temperature defines the ambient temperature for the power supply.
The following measurement results can be used as a reference to estimate the temperature rise inside the enclosure.
The power supply is placed in the middle of the box, no other heat producing items are inside the box
Enclosure:
Load:
Input:
Temperature inside enclosure:
Temperature outside enclosure:
Temperature rise:

Rittal Typ IP66 Box PK 9522 100, plastic, 254x180x165mm
48V, 16A; (=80%) load is placed outside the box
230Vac
65.6°C (in the middle of the right side of the power supply with a distance of 2cm)
24.1°C
41.5K

Jul. 2023 / Rev. 1.4 DS-QS40.481-EN
All parameters are specified at 48V, 20A, 230Vac, 25°C ambient and after a 5 minutes run-in time unless otherwise noted.
www.pulspower.com Phone +49 89 9278 0 Germany

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QS40.481
48V, 20A, SINGLE PHASE INPUT

Q-Series

26.13. MOUNTING ORIENTATIONSMounting orientations other than all terminals on the bottom require 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 in approximately half the lifetime expectancy of A1).
Fig. 26-6
Mounting
Orientation A(Standardorientation)

Output Current

20A

A1

15

Power
Supply10
5
Ambient Temperature0

INPUT OUTPUT

10
Fig. 26-7
Mounting
Orientation B(Upside down)

20

30

40

50

60°C

Output Current

20A
15

A2

10

A1

INPUT OUTPUT

Pow er
Supply5
Ambient Temperature

010Fig. 26-8
Mounting
Orientation C(Table-top
mounting)

20

30

40

50

60°C

Output Current

20A
15

A2
A1

10
5

Ambient Temperature

0
10

40

50

60°C

20A

Pow er
Supply

15
A2

10

A1

5
Ambient Temperature

0
10

20

30

40

50

60°C

Output Current
INPUT OUTPUT

20A

Pow er
SupplyFig. 26-10
Mounting
Orientation E(Horizontal ccw)

30

Output Current
INPUT OUTPUT

Fig. 26-9
Mounting
Orientation D(Horizontal cw)

20

15
A2
A1

10
5
Ambient Temperature

0
10

20

30

40

50

60°C

Jul. 2023 / Rev. 1.4 DS-QS40.481-EN
All parameters are specified at 48V, 20A, 230Vac, 25°C ambient and after a 5 minutes run-in time unless otherwise noted.
www.pulspower.com Phone +49 89 9278 0 Germany

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