
AC Repair and Adjustment Procedures
FRP 25: Thermostat Replacement
HMM-168-A
Cray Research/Silicon Graphics Proprietary
143
Figure 67. Thermostats
Thermostat Installation
1.
Secure the new thermostat to the sensor plate with 2 Phillips screws.
2.
Connect the thermostat wires.
3.
Secure the sensor plate with the four #2 Phillips screws.
4.
Test the thermostat and wires with an ohmmeter.
5.
If a heat gun is not available:
Open the power supply circuit breakers (CB2 through CB7) and blower
circuit breaker (CB8), then close the main disconnect circuit breaker
(CB1) and the WACS circuit breaker (CB9). Ensure that CB1 does not
trip open.
6.
If a heat gun is available:
a. Have a partner watch the exhaust air temperatures on the WACS
display, while you use a heat gun to heat the thermostat to
approximately 150 ˚F (65 ˚C).
Thermostat
Thermostat
Feed-through
Thermostat
View from Cabinet
View from Top
Thermostat
Plate