Chapter 2
Installation and Configuration
NI PS-15 Power Supply User Manual
2-6
ni.com
Parallel Operation
Caution
The power supply must
not
be used in parallel for the purpose of increasing the
output power.
Power supplies can be paralleled for 1+1 redundancy to gain a 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 NI PS-15 power supplies in parallel. If one power supply
unit fails, the other one is automatically able to support the load current
without any interruption. When using this method of building a redundant
system consider the following:
•
The faulty power supply can not be recognized. The green LED will
still be on since it is reverse-powered from the other power supply.
•
It does not cover failures such as an internal short circuit in the
secondary side of the power supply. In such a case (nearly impossible),
the defective unit becomes a load for the other power supplies and the
output voltage can not be maintained.
Recommendations for building redundant power systems:
•
Use separate input fuses for each power supply.
•
When possible, connect each power supply to different phases or
circuits.
Two-Phase Power Operation
The NI PS-15 power supply can operate with two-phase power, as shown
in Figure 2-4.
Figure 2-4.
NI PS-15 in Two-Phase Operation
Before operating the NI PS-15 in this configuration, consider the following:
internal
fused
240 V
+1
0
%
ma
x.
Fuse
L2
L1
L3
L
N
PE
Power Supply
AC
DC
