Equipment replacement
Page 21 of 34
QCA144 1.5 MB/S RPE Cabinet
Maintenance and equipment replacement
Procedure 9
QUX19 Power Unit replacement
1
Set the AC BRKR breaker on the front of the –48 V rectifier to OFF.
2
Set the DC BRKR breaker on the QBL24 battery units (if equipped)
serving the cabinet to OFF.
3
If cabinet is equipped with EMI shields, tag and disconnect cables from
all connectors A, B, C, D, E, F, and G at the rear of the cabinet and
remove shields.
4
Remove screws securing cabinet top assembly (
5
With a soldering iron, disconnect wiring from thermostat under cabinet
top assembly (
6
At the rear of the QUAA3 unit, disconnect cable connectors P1, P5,
P6, and P7 and wiring from terminals 1, 2, 3, 4, 5, and 6 of TB4.
7
At the rear of the QUX19 unit, tag and disconnect power wiring from
TB1 and P10 wiring from TB2.
8
From the ground bus at the right rear of the cabinet, disconnect wiring
from lugs GRD2A, GRD2G, and GRD1C.
9
From the front of the cabinet, remove the screws securing the QUX19
unit to cabinet and remove unit and attached wiring from cabinet.
10
Install replacement QUX19 unit and wiring in cabinet and secure with
mounting screws.
11
From the rear of the cabinet, position the long black and white wires
for the thermostat. Connect and solder connections to thermostat
(
12
Install cabinet top assembly and secure with mounting screws
(
13
Reconnect power wiring to TB1 and P10 wiring to TB2 at rear of
QUX19 unit.
CAUTION
Service in the cabinet is interrupted when replacing the main QUX19
power unit.