Revision 03
August 22, 1997
Section 950-719-100
Page 22
PairGain Engineering - Plant Series
PG-Plus PCS-719
Split-Shelf Powering
One half of the shelf is powered from one -48 V dc source, the other half is powered from another -48 V dc
source. Common equipment circuit cards are powered from both sources. If one power supply should fail, one-
half of the shelf maintains power. Each -48 V dc source is fused at 10 amps.
A four-position jumper is in place on the TB1 block (refer to 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 split-shelf
powering:
1
Ensure that the ground connection is in place.
2
Remove the four-position jumper (refer to Figure 6) and discard.
3
Connect a wire to the -48A-LOW terminal of TB1 (see Figure 7). Connect the opposite end of this wire to
the A CO battery supply at the fuse panel.
4
Connect a wire to the -48B-HIGH terminal of TB1. Connect the opposite end of this wire to the B CO battery
supply at the fuse panel.
5
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.
6
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.
7
Use a short jumper wire to connect the -48 A-LOW and -48 B-LOW terminals of TB1. Make this connection
at the top of the terminal block as shown in Figure 7.
8
Connect a wire from the -48A-HIGH to the-48B-HIGH terminals of TB1. Make this connection at the top
of the terminal block as shown in Figure 7.
Figure 7
Split-Shelf Wiring
