Schneider Electric 890USE17700 - Manual (Page 37)

The STB NIP 2212 NIM
890USE17700 April 2004 37
Logic Power
Introduction Logic power is a 5 VDC power signal on the island bus that the I/O modules require
for internal processing. The NIM has a built-in power supply that provides logic
power. The NIM sends the 5 V logic power signal across the island bus to support
the modules in the primary segment.
External Source
Power Input from an external 24 VDC power supply (See Characteristics of the External
Power Supply, p. 39) is needed as the source power for the NIM’s built-in power
supply. The NIM’s built-in power supply converts the incoming 24 V to 5 V of logic
power. The external supply must be rated safety extra low voltage (SELV-rated).
CAUTION
IMPROPER GALVANIC ISOLATION
The power components are not galvanically isolated. They are intended
for use only in systems designed to provide SELV isolation between the
supply inputs or outputs and the load devices or system power bus. You
must use SELV-rated supplies to provide 24 VDC source power to the
NIM.
Failure to follow this precaution can result in injury or equipment
damage.