Applications; Parallel Connection To Increase Power Rating - Siemens PSU300B Manual

Applications

9.1

Parallel connection to increase power rating

To increase the power rating, SITOP PSU300M/300B power supplies of the same type can
be directly connected in parallel.
The following must be observed:
● The cables connected to each power supply at terminals "+" and "-" must have identical
lengths and the same cable cross-sections (or the same impedance) up to a common
external connection point (terminal strip) if possible.
● The power supplies connected in parallel must be switched on simultaneously with a
common switch in the line feeder cable (e.g. with the main switch available in control
cabinets).
● The output voltages measured in no-load operation for the power supplies that are not yet
connected in parallel should not deviate more than a maximum of 50 mV. This usually
corresponds to the factory setting. If the output voltage is changed, you should connect
the "-" terminals and then, in no-load operation, measure the voltage difference between
the "+" terminals that have not yet been connected. The voltage difference should not
exceed 50 mV.
● Place selector switch A at "ON" (see Section Change-over switch (Page 15))
Figure 9-1
SITOP PSU300M/300B
Manual, 11.2014, C98130-A7574-A2-2-7629
Parallel connection, correct and incorrect
9
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