Trane IntelliPak CGAF Series - Page 58

58
System Testing & Troubleshooting
DIAGNOSTIC DISPLAYED REASON FOR DIAGNOSTIC UCM’S REACTION RESET REQUIRED
Liquid Pressure Sensor Fail Circuit 2 (Circuit #2 40-60 Ton units only) Problem: Circuit 2 Saturated Liquid Line Pressure sensor input is out of range. Check: Check field/unit wiring between Sensor and SSM.
The unit is reading a signal that is out of range for the Circuit 2 Saturated Liquid Line Pressure Sensor input on the SSM. (Pressure < 0 PSIG or Pressure > 400 PSIG).
The Superheat/Subcool calculation is invalid and the vaiues are set to zero. No other change in unit operation occurs. This dia
g
nostic is for information
only.
(INFO) An automatic reset occurs after the Circuit 2 Saturated Liquid Pressure Sensor input returns to its allowable range. In order to prevent rapid cycling of the Diagnostic, there is a 10 second delay before the automatic reset.
Low Ambient Evaporator Solution Pump Override Problem: Outside Air Temp too low, reques t Solution Pum p to run to keep Solution moving.
The Outside Air (Ambient) temperature is below the Low Ambient Evap Pump Override Temp Setpoint.
The Evaporator Solution Pump Relay is energized while this condition exists.
(PAR) An automatic reset occurs after the Outs ide Air Tem p increases 5 deg F or more above the Low Ambient Evaporator Pump Override Temp Setpoint.
Low Solution Cutout Temperature (Auto) Problem: The Evaporator Leaving or Enterin
g
Solution Temperature is too
low.
While no compressors were running, the Evaporator Solution Temperature(s) went below the Low Solution Cutout Tem p Setpoint.
While this diagnostic is active, Compressors are prevented from staging on. The Unit will deenergize the following: Compressor Relays, LPC Bypass Relays, Liquid Line Solenoids, and HGBP Relay.
(PAR) An automatic reset occurs after the Evaporator Solution Temperature(s) rises 4 deg F or more above the Low Solution Cutout Temperature Setpoint.
Low Solution Cutout Temperature (Man) Problem: The Evaporator Leaving or Enterin
g
Solution Temperature is too
low.
While compressors were runnin
g
, the
Evaporator Solution Temperature(s) went below the Low Solution Cutout Temperature Setpoint.
A "Lockout all Circuits" request is issued to the Compressor Staging Function. Compressors are prevented from staging on and the Unit will de-energize the following relays: Compressor Relays, LPC Bypass Relays, Liquid Line Solenoids, and HGBP Relay.
(PMR) A manual reset is required after this diagnostic occurs. The Diagnostic can be reset by the unit mounted Human Interface Module or Tracer, or by cycling power to the CGM.
Low Pressure Control Open - Circuit 1 Problem: The refrigerant in Circuit 1 is cold and may cause the Solution in the Chiller barrel to become too cold. Also, there may be a state of charge issue with Circuit 1.
With one or more compressors running, the higher pressure of the two LPC switches on Circuit 1 has opened 6 times with the LPC Bypass relay de-energized, or it was open at the time the LPC Bypass Relay de- energized. On a standard unit this is the 45 PSIG LPC switch, but can be 20 PSIG or lower on units with a lower Leaving Solution Setpoint range.
A “Lockout Circuit # 1” request is issued to the Compressor Staging Control function. The Compressor Relays, LPC Bypass Relay, Liquid Line Solenoid Relay, and Hot Gas Bypass Relay for Circuit 1 are all de-energized.
(PMR) A manual reset is required anytime after the Diagnostic is set. The Diagnostic can be reset by the Human Interface or Tracer, or by cycling power to the CGM.