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Notes on Operation
Product manual | Version: 1.0.0
33
Compact Power Supply
7
Notes on Operation
7.1 Inrush Current
If several products are connected in parallel and supplied on the input side using the
same circuit, higher inrush currents can result. In this case, the use of auxiliary relays,
which cause a time delay in startup, is recommended.
The maximum number of products that can be operated in parallel on one circuit is given
by the sum of the leakage currents. According to EN 62368-1, this sun must not exceed
the maximum value of 3.5 mA.
The maximum number of products that can be switched on at the same time depends,
among other things, on the backup fuse used and the impedance of the supply network.
7.2 Parallel Connection (on the Output Side)
In parallel operation, set the output voltage of the products that will be connected in paral-
lel to precisely the same value, if possible. The resistance of the conductors between the
power supply units and the load must be nearly identical. Only connect products of the
same type in parallel.
Use external rail-mount terminal blocks when connecting in parallel. A parallel connection
directly on the connectors on the secondary side of the product is not allowed.
To decouple the outputs in parallel mode, a suitable redundancy module or diodes in the
positive path are recommended. These diodes must be designed for the product’s maxi-
mum output current.
7.3 Derating
The maximum load is dependent on the surrounding air temperature and the input volt-
age.
7.3.1 Derating (Temperature-Dependent)
Table 29: Nominal values per UL
Parameter
Value per UL
IN
100 … 120 VAC / 200 … 240 VAC; 1.8 A / 50 … 60 Hz
OUT
24 VDC, 3.3 A / 24 VDC, 4.2 A (U
IN
> 110 VAC)
Ambient temp.
+55 °C
Restrictions (derating) apply when the power supply unit is used in applications that ex-
ceed its performance specifications; these are listed below:
Table 30: Deratings
Nominal voltage
Temperature value T
U
Derating
90 ... 264 VAC
> +55 °C
−2.67 %/K
< 110 VAC
–
− 2.0 %/V
< 140 VDC
–
− 1.33 %/V
