Circuit Pack Descriptions
7-84 Issue 8.0 July 2002
The LSSW circuit packs also provide power to the protection switching relays on
the service DS3 and STS1E circuit packs. The LSSW circuit pack in the IN slot
powers the protection switching relays on the DS3 and STS1E circuit packs in
slots 1A through 4B. The LSSW circuit pack in the OUT slot powers the protection
switching relays on the DS3 and STS1E circuit packs in slots 5A through 8B.
The LSSW circuit pack monitors the two −48 volt sources to the circuit pack and
any failures are reported to the board controller. If the LSSW circuit pack detects a
failure of the onboard fuse or power converter, the red FAULT LED will light. If the
fuse or power converter fails, the LNCTL circuit pack provides +5 volts to light the
FAULT LED on the LSSW circuit pack.