York YCIV Series, Installation Operation & Maintenance

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JOHNSON CONTROLS
309
SECTION 9 - MAINTENANCE
FORM 201.23-NM2
ISSUE DATE: 09/25/2020
9
PROBLEM POSSIBLE CAUSE ACTION
System Fault:
High
Discharge
Temperature
Discharge Temperature Sensor is defective. Check Sensor.
Condenser Fans NOT operating or are running back-
wards.
Check Fans.
Coils dirty. Check and clean Coils.
High Superheat.
Measure Superheat with gauges and thermo-
couple. Determine cause.
System Fault:
High Motor
Temperature
High Motor temperature input from one of the sensors
Refrigerant charge low. Check subcooling.
Excess charge in system, High discharge
pressure.
Check subcooling.
High Superheat. Drain/Feed Valves
NOT controlling. Isolate cause.
Motor Sensor reading incorrectly.
Program panel to ignore a single sensor.
Economizer Solenoid energized at low
speeds. Valve is leaking through.
System Fault:
Low
Suction
Pressure
Low charge. Check subcooling.
Transducer reads incorrectly. Check transducer against a gauge.
Suction Temp. Sensor reads incorrectly. Check sensor against a thermocouple.
Low flow. Check flow.
Feed or Drain Valve NOT operating
Check Feed and Drain Valve operation.
Check superheat.
Feed or Drain Valve defective.
Check Feed and Drain Valve operation.
Check superheat.
System Fault:
Discharge
Pressure
Limiting
Discharge Transducer is defective. Check transducer against a gauge.
Ambient Temp. very high. Normal operation.
Fans NOT operating. Check fan operation.
Remote or local discharge pressure load limiting is
programmed.
Normal operation.
System Fault:
Motor
Current
Limiting
High motor current
has activated
current limiting
Ambient temperature is high,
normal response from controller
Remote or panel limiting is in
effect, Normal response.
Excess charge in system, adjust charge.
Condenser coils dirty, Clean condenser.
Fans NOT operating, Check fans.
Vsd Fault:
High
Baseplate
Temperature
Coolant level low. Add coolant.
Glycol Pump is defective. Replace Glycol Pump.
VSD Board is defective Replace VSD Logic Board.
IBGT Module is defective. Check defective IGBT Module.
Vsd Fault:
Low Dc
Bus Voltage
SCR / Diode Module is defective. Check SCR / Diode Module.
SCR Trigger Board is defective. Check SCR Trigger Board.