Rockwell Automation Publication 1606-RM110A-EN-P - July 2020
31
Redundancy Power Supply - 24V, 10 A, 240 W, Single-phase Input
Parallel Use For Redundancy
Power supplies can be paralleled for redundancy to gain higher system
availability. The unit is already equipped with a MOSFET as decoupling device
on the output to avoid, that a faulty unit becomes a load for the other power
supplies and the output voltage cannot be maintained any more.
Recommendations for building redundant power systems:
a. Use separate input fuses for each power supply.
b. Monitor the individual power supply units by utilizing the built-in DC
OK relay contacts on each power supply.
Figure 38 - Wiring Diagram, 1+1 Redundancy for 10 A Output Current
Figure 39 - Wiring Diagram, N+1 Redundancy for 20A Output Current
(a)
24V, 10A
Load
Failure
Monitor
L
N
PE
I
I
L N PE
+
-
Power Supply
DC-OK
DC-
OK
Output 24V 10A
Input
L N PE
+
-
Power Supply
DC-OK
DC-
OK
Output 24V 10A
Input
(a) Observe the temperature derating requirements of
and
for n+1
redundancy applications.
24V, 20A
Load
Failure
Monitor
L
N
PE
L N PE
+
-
Power Supply
DC-OK
DC-
OK
Output 24V 10A
Input
I
I
I
L N PE
+
-
Power Supply
DC-OK
DC-
OK
Output 24V 10A
Input
L N PE
+
-
Power Supply
DC-OK
DC-
OK
Output 24V 10A
Input
IMPORTANT
Use separate mains systems for each power supply whenever it is
possible.