Applications
5.3 Series connection for increased voltage
5.3
Series connection for increased voltage
To achieve a higher output voltage, two LOGO!Power 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 grounding point of the secondary output voltage, voltages of +2×UA, ±UA or -
2×UAcan be implemented.
In the case of asymmetric load distribution, it is not possible to ensure correct functionality.
WARNING
When two power supplies are connected in series, it is not possible to ensure the
permanently permissible SELV voltage of maximum of 60 V DC acc. to EN 60950 in the
event of a fault.
Figure 5-3
Series connection
5.4
Protection against short-time voltage dips
During a drop in the primary-side supply voltage, the LOGO!Power power supplies still
maintain the output voltage over a short millisecond period (see section Technical data, Input
(Page 23)).
LOGO!Power
Operating Instructions, 02.2011, C98130-A7560-A999-1-7619
21
SIEMENS [ Siemens Semiconductor Group ]
