EN
QT20.241, QT20.241-C1 Installation Manual
Product Description
The QT20.241 is a DIN-rail mountable power supply for three-phase mains systems, which provides a
floating, stabilized and galvanically separated SELV/PELV output voltage.
The QT20.241-C1 device is the same as the QT20.241 but with conformal coated pc-boards.
Intended Use
This 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 malfunction may cause severe personal injury or threaten human life.
Installation Instructions
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 a minimum 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.
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 isolation of the device is designed to withstand impulse voltages of overvoltage category III
according to IEC 60664-1.
Above 2000m the overvoltage category is reduced to level II.
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 400Vac. The device is not designed
to be used on corner grounded delta systems.
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 6000m (19685ft). See additional requirements in the product
datasheet for use above 2000m (6560ft).
Keep the following minimum installation clearances: 40mm on top, 20mm on the bottom, 5mm left and
right side. Increase the 5mm to 15mm 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 16A (IEC) and 15A (UL) without
additional protection device. If an external fuse is utilized, do not use circuit breakers smaller than 6A
B- or 3A C-Characteristic to avoid a nuisance tripping of the circuit breaker.
The maximum surrounding air temperature is +70°C (+158°F). 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.
Substitution of components may impair suitability for this environment.
Do not disconnect the device or operate the voltage adjustment unless power has been switched off or
the area is known to be non-hazardous.
Functional Description
The output is electronically protected against no-load, overload and short circuit and can supply any
kind of loads, including unlimited inductive and capacitive loads.
Do not apply return voltages from the load to the output terminals higher than 34V.
The output voltage can be adjusted with a small flat-blade screwdriver behind the flap on the front.
The green DC-OK LED reports an output voltage above 90% of the adjusted voltage of a running
device.
The DC-OK relay monitors the output voltage and the contact is closed when the DC-OK LED is on.
Contact ratings: 60Vdc 0.3A, 30Vdc 1A, 30Vac 0.5A for resistive loads.
The red overload LED is on when the output voltage falls below 90% of the adjusted value or in case
of a short circuit in the output or too high temperature. Input voltage is required.
The device is equipped with an over-temperature protection. In case of a high temperature, the output
shuts down and starts automatically again after cooling off.
The device is designed to deliver 30A output current for up to 4s with nominal output voltage.
Devices can be paralleled to increase the output power. The ambient temperature is not allowed to
60°C. The output voltage shall be adjusted to the same value (±100mV) with the same load
conditions on all devices, or the devices can be left with the factory settings. If more than three
devices are connected in parallel, a diode, fuse or circuit breaker with a rating of 25A is required on
each output.
Same devices can be connected in series for higher output voltages. It is allowed to connect as many
devices in series as needed, providing the sum of the output voltage does not exceed 150Vdc.
In case of an internal defect, a redundant circuit limits the maximum output voltage to 35V. The output
shuts down and automatically attempts to restart.
Technical Data
All values are typical figures specified at 3x 400Vac 50Hz input voltage,
symmetrical phase voltages, 24V, 20A output load, 25°C ambient
temperature and after a 5 minutes run-in time unless otherwise noted.
Output voltage
DC 24V
Nominal
Adjustment range
24 – 28Vdc
Factory setting 24.1V
Output current
Continuous:
20 – 17.5A
Below +60°C ambient
15 – 13.1A
At +70°C ambient
Short-term, up to 4s:
30 – 26.0A
Below +70°C ambient
Derate linearely b60°C and +70°C
Input voltage AC
3AC 380 - 480V
±15%
Mains frequency
50 – 60Hz
±6%
Input current AC
0.79 / 0.65A
At 3x400 / 480Vac
Power factor
0.94 / 0.95
At 3x400 / 480Vac
Input inrush current
3 / 3A peak
At 3x400 / 480Vac,
temp. independent
Efficiency
95.0 / 94.8%
At 3x400 / 480Vac
Losses
25.3 / 26.4W
At 3x400 / 480Vac
Hold-up time
22 / 22ms
At 3x400 / 480Vac
Temperature range
-25 to +70°C
Max. wire size (litz wire)
4mm²
Wire size AWG
AWG 20-10
Max. wire diameter
2.8mm
Wire stripping length
10mm / 0.4inch
Size (wxhxd)
65x124x127mm Without
DIN-rail
Weight
870g / 1.92lb
Functional Diagram
L2
L3
L1
+
+
-
-
Output
Over-
Voltage
Protection
PFC
Converter
Voltage
Regulator
Power
Converter
Output
Filter
Output
Power
Manager
Temper-
ature
Shut-
down
Input Filter
Input Rectifier
Inrush Current
Limiter
V
OUT
DC-OK
Contact
DC-OK
LED
DC-ok
Relay
13
14
Overload
LED
Output Characteristic
Output voltage
35A
24V
Output current
12V
0V
5A
15A
20A
25A
0A
Adjustment range
28V
10A
30A
B
A
A: continuous
B: for 4s
Temperature Range
Allowed output current at 24V
Ambient temperature
0A
-25
A: continuous
B: short term (typ. 4s)
30A
0
+70°C
15A
B
20A
+60
A