Trane CSRA025FAF0, Installation Operation & Maintenance

Page: 12 / 83

12 CSRA-SVX02A-EN
General
Information
Compressor Motor Winding Thermostats (Standard)
A thermostat is embedded in the motor windings of each Scroll compressor.
Each thermostat is designed to open if the motor windings exceeds
approximately 221°F. The thermostat will reset automatically when the
winding temperature decreases to approximately 181°F. Rapid cycling, loss
of charge, abnormally high suction temperatures, or the compressor running
backwards could cause the thermostat to open. During a request for
compressor operation, if the Compressor Module detects a problem outside
of it's normal parameters, it turns any operating compressor(s) on that circuit
“Off”, locks out all compressor operation for that circuit, and initiates a
manual reset diagnostic.
Low Ambient Compressor Lockout (Standard)
When low ambient compressor lockout is enabled, the compressors are not
allowed to operate if the temperature of the outside air falls below the
lockout setpoint. Compressor operation is enabled when the temperature
rises 5°F above the lockout setpoint. The setpoints and enable/disable
option is programmable at the Human Interface inside the unit control panel.
The default setting is 30°F.
Note: The unit is wired so the CGM monitors incoming power for proper
phase sequencing. Observe proper polarity of internal wiring during service
procedures.
Short Cycle Protection (Standard)
If compressor operation is interrupted by a loss of power or by a manual
reset diagnostic, a minimum of one minute must elapse before the affected
compressor(s) will be allowed to restart for “Process” applications. A
minimum of three minutes must elapse before the affected compressor(s)
will be allowed to restart for “Comfort Cooling” applications.
Hot Start (Load Limit) Control (Standard)
Each time the system is started and the control of the CGM transitions from
“Loop Stabilization” to either “Process” or “Comfort Cooling”, if the Leaving
Solution Temperature (LST) is higher than the programmable Hot Start Load
Limit Setpoint (HSLLS), the lag compressor on each circuit will be prevented
from operating until the leaving solution temperature is lowered by 5°F below
the HSLLS.
If the Hot Start Limit time interval elapses before the LST is 5°F below the
HSLLS, the control will transition immediately into the Hot Operation mode.
Hot Operation mode is programmable to:
1. Do not limit capacity, initiate an informational diagnostic until the LST falls
5°F below the HSLLS.
2. Limit the capacity to 50 percent (one compressor per circuit), initiate an
auto reset diagnostic until the LST falls 5°F below the HSLLS.