Power Supply PS1000-A6-12.16
Application Notes
20
21
-1
1
41
27.6
Parallel Use for Redundancy
Power supplies can be paralleled for redundancy to gain higher system availability.
Redundant systems require a certain amount of extra power to support the load in case
one power supply unit fails. The simplest way is to put two decoupled power supplies
in parallel. This is called a 1+1 redundancy. In case one power supply unit fails, the other one
is automatically able to support the load current without any interruption. Redundant systems
for a higher power demand are usually built in a N+1 method. E.g. five power supplies,
each rated for 16A are paralleled to build a 64A redundant system. For N+1 redundancy
the same rules apply as for increasing the output power, see also chapter 27.5.
Recommendations for building redundant power systems:
•
Use separate input fuses for each
power supply.
•
Monitor the individual power supply units. Therefore, use the DC-OK relay contact
of the power supply.
•
It is desirable to set the output voltages of all units to the same value (± 100mV) or leave
it at the factory setting.
Figure 27.6 1+1 redundant configuration with one redundancy module
Note
Always use a redundancy module to decouple power supplies from each other. This prevents
that the defective unit becomes a load for the other power supplies and the output voltage
cannot be maintained any more.
L
PE
Load
Failure
Monitor
optional
N
I
I
Power
Supply
Output
DC-
OK
+
-
+
-
o o
Input
L N
Power
Supply
Output
DC-
OK
+
-
+
-
o o
Input
L N
YR40.242
Redundancy
Module
Output
Input
1
Input
2
+
-
+
-
+
-
PS1000-D2-
24.40.RM
Redundancy
module
