Siemens SITOP series - Series Connection for Higher Voltage

Applications
9.3 Series connection for increased voltage
SITOP modular 1ph/2ph
Operating Instructions, 06.2014, C98130-A7548-A1-3-7629
61
9.3
Series connection for increased voltage
To achieve an output voltage of 48 VDC, two 24 V SITOP modular power supplies of the
same type can be connected in series. In this case, connect the "-" terminal of the first power
supply to the "+" terminal of the second power supply. The "+" terminal of the first power
supply and the "-" terminal of the second power supply are routed to the load.
Depending on the grounding point of the secondary output voltages, voltages of +48 V,
±24 V or -48 V can be realized.
In the case of an asymmetric load distribution, it is not possible to guarantee correct
functionality.
WARNING
SELV is not guaranteed in the case of a fault
When connecting two power supplies in series, the continuous, permissible SELV voltage
of a maximum of 60 VDC according to EN 60950 cannot be guaranteed in the case of a
fault.
Figure 9-4 Series connection