Parallel Connection To Increase Power Rating - Siemens PSU8600 Manual

12.3

Parallel connection to increase power rating

To increase the power rating, two SITOP PSU8600 power supplies can be directly
connected in parallel.
The following must be observed:
● The cables connected to each basic device at terminals "Output" and "0 V" must have, as
far as possible, identical lengths and the same cable cross-sections (or the same
impedance) up to a common external connection point (terminal strip).
● The basic devices 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 basic devices that are not yet
connected in parallel should not deviate more than a maximum of 50 mV. If the output
voltages differ by more than this value, then the "0 V" terminals should be connected
together, and in no-load operation the voltage difference between the "Output" terminals
(that are still not connected with one another), measured and adjusted to be the same
using the voltage potentiometer. The voltage difference should not exceed 50 mV.
● Select the "soft" output characteristic at selector switch "SOC1" of each basic device (see
Setting the output characteristic (Page 71))
NOTICE
Protective circuit when convicting more than two basic devices in parallel
When connecting more than two basic devices in parallel, additional measures must be
taken to prevent high backward feeding currents in the event of a secondary device fault.
For this purpose, a suitable protective circuit (e.g. decoupling diode or DC-capable circuit
breaker) must be installed between each "Output" terminal of the basic devices and the
common connection point.
Power supply system PSU8600
Manual, 05.2017, A5E36758446-3-76
12.3 Parallel connection to increase power rating
Applications
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