
AC Repair and Adjustment Procedures
FRP 29: Main Disconnect Circuit Breaker (CB1) Replacement
HMM-168-A
Cray Research/Silicon Graphics Proprietary
153
You may also open, lock, and tag the customer’s wall breaker(s).
3.
Remove the air filter to provide greater access to the power box. Refer to
FRP 37
for removal instructions.
4.
Remove the cover from the power box using the following steps:
a. Use a #2 Phillips screwdriver to remove the screws that hold the cover
in place.
b. Pull the cover straight up, then remove it from the cabinet. Be careful
not to damage the inlet air thermistors or the EMI gasket on the bottom
of the cover.
5.
Carefully record the positions of the wires that connect to CB1.
6.
Use the #2 Phillips screwdriver to remove the input (line) wires and input
shunt trip wire from CB1. The input wires are located on the module side
of CB1.
NOTE:
The Ferrules used on the wires sometimes get stuck in the
breaker wire cage. Use care to avoid this.
7.
Remove the circuit breaker from the DIN rail:
a. Insert a small flatblade screwdriver into the slot in the left spring latch.
b. Using the bottom of the circuit breaker as a fulcrum, press the
screwdriver handle toward the breaker to pull the spring latch away
from the DIN rail. Refer to
.
c. Hold the spring latch in this disengaged position, and rotate the
front-left portion of the circuit breaker up and out of the DIN rail.
d. Use the same technique to open the right spring latch, then rotate the
circuit breaker up and off the DIN rail.
8.
Use the #2 Phillips screwdriver to remove the output (load) wires from the
circuit breaker.