Operating instructions
ACZ/AGZ Troubleshooting Chart
PROBLEM POSSIBLE CAUSES POSSIBLE CORRECTIVE STEPS
1. Main Switch. 1. Close Switch.
2. Fuse Blown. Circuit breakers open 2. Check electrical circuits and motor windings
for shorts or grounds. Investigate for
possible overloading. Replace fuse or reset
breakers after fault is corrected. Check for
loose or corroded connections.
3. Thermal overloads tripped 3. Overloads are auto-reset Check unit closely
when unit comes back on line. Allow time for
auto-reset.
4. Defective contactor or coil. 4. Repair or replace
5. System Shutdown by equipment protection
devices
5. Determine type and cause of shutdown and
correct it before resetting equipment
protection switch
Compressor
Will Not Run
6. No cooling required 6. None. Wait until unit class for cooling
7. Liquid line solenoid will not open 7. Repair or replace solenoid coil. Check wiring
8. Motor electrical trouble 8. Check motor for opens, shorts, or burnout
9. Loose wiring 9. Check all wire junctions. Tighten all terminal
screws
1. Low or no refrigerant charge
1. Repair and recharge
2. Compressor running in reverse
2. Check unit and compressor for correct
phasing
Compressor
Noisy Or
Vibrating
3. Improper piping support on suction or
discharge
3. Relocate, add, or remove hangers
4. Worn compressor isolator bushing
4. Replace
5. Worn Compressor
5. Replace
1. Noncondensables in system 1. Extract the noncondensables with approved
procedures
2. System overcharged with refrigerant 2. Remove excess, check liquid subcooling
High Discharge
Pressure
3. Optional discharge shutoff valve partially
closed
3. Open valve
4. FanTrol wiring not correct 4. Check FanTrol wiring
5. Fan not running 5. Check electrical circuit, Check fan motor
6. Dirty condenser coil 6. Clean coil
7. Air recirculation 7. Correct
1. Refrigerant flood back 1. Correct
2. Wind blowing into coil at low ambient 2. Shield coil from direct wind
3. Faulty condenser temperature regulation 3. Check condenser control operation
4. Insufficient refrigerant in system
5. Low suction pressure
4. Check for leaks. Repair and add charge
5. See corrective steps for Low Suction
Pressure
Low Discharge
Pressure
6. Only one compressor operating 6. See corrective steps for Compressor Will Not
Stage Up
1. Excessive water temperature 1. Check control settings
2. Excessive load 2. Reduce load or add additional equipment
High Suction
Pressure
3. Expansion valve overfeeding 3. Check remote bulb. Regulate superheat
4. Compressors running in reverse 4. Check for proper phasing
1. Rapid load swings 1. Stabilize load
2. Lack of refrigerant 2. Check for leaks, repair, add charge. Check
liquid sight glass
3. Clogged liquid line filter-drier 3. Check pressure drop across filter-drier.
Replace
4. Expansion valve malfunctioning 4. Check and reset for proper superheat
5. Condensing temperature to low 5. Check means for regulating condenser
temperature
6. Compressor will not unload 6. See corrective steps for Compressor Staging
Intervals Too Low
Low Suction
Pressure
7. Insufficient water flow 7. Adjust flow
8. Evaporator head ring gasket slippage 8. Take pressure drop across vessel and
contact factory to obtain design pressure
drop for that vessel
9. Evaporator dirty 9. Clean chemically
10. Rapid load swings 10. Stabilize load
Continued next page.
IMM ACZ/AGZ-4 ACZ / AGZ-BM 69