Section 950-719-100
August 22, 1997
Revision 03
PG-Plus PCS-719
PairGain Engineering - Plant Series
Page 21
Redundant-Shelf Powering
Each circuit card in the COTS receives power from two -48 V dc sources. If one -48 V dc source is lost, the other
-48 V dc source provides power to the shelf circuit cards. Each -48 V dc source is fused at 20 amps.
A four-position jumper is in place on the TB1 block (Figure 6). This jumper shorts all of the 48 VDC inputs
together to prevent an alarm situation when only one input feed wire is connected. To provide redundant-shelf
powering:
1
Ensure that the ground connection is in place.
2
Remove the four-position jumper from TB1.
3
Cut the four-position jumper in half, then cut out a small strip to ensure a gap between the two pieces when
they are replaced (see Figure 6).
4
Replace the two pieces on the TB1 block, connecting TB1-1 to TB1-2 with one piece; then TB-3 to TB-4
with the second piece.
5
Connect a wire to the -48A-LOW terminal of TB1. Connect the opposite end of this wire to the CO A battery
supply terminal at the fuse panel (labeled -48A-HIGH).
6
Connect a wire to the -48B-HIGH terminal of TB1. Connect the opposite end of this wire to the CO B battery
supply at the fuse panel (labeled -48B-HIGH).
7
Connect a wire from the Battery Return terminal in position 5 of TB1 on the COTS backplane to the A CO
battery return at the fuse panel.
8
Connect a wire from the Battery Return terminal in position 6 of TB1 on the COTS backplane to the B CO
battery return at the fuse panel.
Figure 6
Redundant Shelf Power Wiring
Summary of Contents for Pairain PG-Plus PCS-719
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