Parallel Connection For Redundancy - Siemens SITOP PSU300S Manual

9.2

Parallel connection for redundancy

Connecting several 24 V power supplies in parallel for redundancy purposes is required if
especially high demands are placed regarding the availability of a reliable 24 V power
supply.
Using the SITOP PSE202U redundancy module, two power supplies of the same type up to
20 A can be decoupled (Figure 9-2 Redundant configuration with two power supplies and
SITOP PSE202U redundancy module (Page 55)). When one of the devices fails, then the
other automatically takes over the power supply. If one of the power supplies fails, then this
is signaled using an LED on the redundancy module as well as an isolated relay contact.
For higher output current, each power supply must be connected to a redundancy module
(Figure 9-3 Redundant configuration with two power supplies and two SITOP PSE202U
redundancy modules (Page 55)). When dimensioning the system, it must be ensured that
n+1 redundant connected power supplies can handle the total power requirement of the
remaining n power supplies.
Note
For a high reliability of the supply, it is recommended that the redundant switched power
supplies are fused separately on the line-side and, if possible, be connected to different
power supply networks.
Figure 9-2
Figure 9-3
SITOP PSU300S
Manual, 12.2016, C98130-A7587-A1-7-7629
Redundant configuration with two power supplies and SITOP PSE202U redundancy
module
Redundant configuration with two power supplies and two SITOP PSE202U redundancy
modules
9.2 Parallel connection for redundancy
Applications
55