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AGZ-D Troubleshooting Chart
PROBLEM
1.
Main switch.
2.
Fuse blown. circuit breakers open
3.
Thermal overloads tripped
Compressor Will
4.
Defective contactor or coil.
Not Run
5.
System shutdown by equipment protection devices
6.
No cooling required
7.
Liquid line solenoid will not open
8.
Motor electrical trouble
9.
Loose wiring
1.
Low or no refrigerant charge
2.
Compressor running in reverse
Compressor Noisy
3.
Improper piping support on suction or discharge
Or Vibrating
4.
Worn compressor isolator bushing
5.
Worn Compressor
1.
Noncondensables in system
2.
System overcharged with refrigerant
3.
Optional discharge shutoff valve partially closed
High Discharge
Pressure
4.
FanTrol wiring not correct
5.
Fan not running
6.
Dirty condenser coil
7.
Air recirculation
1.
Refrigerant flood back
2.
Wind blowing into coil at low ambient
3.
Faulty condenser temperature regulation
Low Discharge
4.
Insufficient refrigerant in system
Pressure
5.
Low suction pressure
6.
Only one compressor operating
1.
Excessive water temperature
2.
Excessive load
High Suction
Pressure
3.
Expansion valve overfeeding
4.
Compressors running in reverse
1.
Rapid load swings
2.
Lack of refrigerant
3.
Clogged liquid line filter drier
4.
Expansion valve malfunctioning
5.
Condensing temperature too low
Low Suction
Pressure
6.
Compressor will not unload
7.
Insufficient water flow
8.
Evaporator head ring gasket slippage
9.
Evaporator dirty
10. Rapid load swings
1.
Defective capacity control
Compressor Will
2.
Faulty thermostat stage or broken wire
Not Stage Up
3.
Stages not set for application
1.
Thermostat control band not set properly
Compressor
2.
Faulty water temperature sensor
Staging Intervals
3.
Insufficient water flow
Too Short
4.
Rapid load swings
IMM 1078
POSSIBLE CAUSES
AGZ 030C through 190C
POSSIBLE CORRECTIVE STEPS
1.
Close switch.
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.
Overloads are auto-reset. Check unit closely when
unit comes back on line. Allow time for auto-reset.
4.
Repair or replace
5.
Determine type and cause of shutdown and correct
it before resetting equipment protection switch.
6.
None. Wait until unit calls for cooling.
7.
Repair or replace solenoid coil. Check wiring.
8.
Check motor for opens, shorts, or burnout.
9.
Check all wire junctions. Tighten all terminal screws.
1.
Repair and recharge
2.
Check unit and compressor for correct phasing
3.
Relocate, add, or remove hangers
4.
Replace
5.
Replace
1.
Extract the noncondensables with approved
procedures.
2.
Remove excess, check liquid subcooling.
3.
Open valve.
4.
Check FanTrol wiring.
5.
Check electrical circuit, Check fan motor.
6.
Clean coil.
7.
Correct.
1.
Correct.
2.
Shield coil from direct wind, Wind guards are
available.
3.
Check condenser control operation.
4.
Check for leaks. Repair and add charge.
5.
See corrective steps for Low Suction Pressure.
6.
See corrective steps for Compressor Will Not Stage
Up.
1.
Check control settings.
2.
Reduce load or add additional equipment.
3.
Check remote bulb. Regulate superheat.
4.
Check for proper phasing.
1.
Stabilize load.
2.
Check for leaks, repair, add charge. Check liquid
sight glass.
3.
Check pressure drop across filter drier. Replace.
4.
Check and reset for proper superheat.
5.
Check means for regulating condenser temperature.
6.
See corrective steps for Compressor Staging
Intervals Too Low.
7.
Adjust flow.
8.
Take pressure drop across vessel and contact
factory to obtain design pressure drop for that vessel.
9.
Clean chemically.
10. Stabilize load.
1.
Replace.
2.
Replace.
3.
Reset thermostat setting for application.
1.
Set control band wider.
2.
Replace.
3.
Adjust flow.
4.
Stabilize load.
78
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