Daikin AGZ 025D Operating & Maintenance Manual

Daikin AGZ 025D Operating & Maintenance Manual Manual pdf 79 page image

OMM 1166-1 AGZ 025D through 190D 79AGZ-D Troubleshooting ChartPROBLEM POSSIBLE CAUSES POSSIBLE CORRECTIVE STEPSCompressor WillNot Run1. Main switch. 1. Close switch.2. Fuse blown. circuit breakers open2. Check electrical circuits and motor windings forshorts 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 whenunit comes back on line. Allow time for auto-reset.4. Defective contactor or coil. 4. Repair or replace5. System shutdown by equipment protection devices 5. Determine type and cause of shutdown and correctit before resetting equipment protection switch.6. No cooling required 6. None. Wait until unit calls 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.CompressorNoisy Or Vibrating1. Low or no refrigerant charge2. Compressor running in reverse3. Improper piping support on suction or discharge4. Worn compressor isolator bushing5. Worn Compressor1. Repair and recharge2. Check unit and compressor for correct phasing3. Relocate, add, or remove hangers4. Replace5. ReplaceHigh DischargePressure1. Noncondensables in system 1. Extract the noncondensables with approvedprocedures.2. System overcharged with refrigerant 2. Remove excess, check liquid subcooling.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 coil7. Air recirculation6. Clean coil.7. Correct.Low DischargePressure1. Refrigerant flood back 1. Correct.2. Wind blowing into coil at low ambient 2. Shield coil from direct wind, Wind guards areavailable.3. Faulty condenser temperature regulation 3. Check condenser control operation.4. Insufficient refrigerant in system5. Low suction pressure4. Check for leaks. Repair and add charge.5. See corrective steps for Low Suction Pressure.6. Only one compressor operating 6. See corrective steps for Compressor Will Not StageUp.High SuctionPressure1. Excessive water temperature 1. Check control settings.2. Excessive load 2. Reduce load or add additional equipment.3. Expansion valve overfeeding 3. Check remote bulb. Regulate superheat.4. Compressors running in reverse 4. Check for proper phasing.Low SuctionPressure1. Rapid load swings 1. Stabilize load.2. Lack of refrigerant 2. Check for leaks, repair, add charge. Check liquidsight 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 too low 5. Check means for regulating condensertemperature.6. Compressor will not unload 6. See corrective steps for Compressor StagingIntervals Too Low.7. Insufficient water flow 7. Adjust flow.8. Evaporator head ring gasket slippage 8. Take pressure drop across vessel and contactfactory to obtain design pressure drop for that vessel.9. Evaporator dirty10. Rapid load swings9. Clean chemically.10. Stabilize load.Compressor WillNot Stage Up1. Defective capacity control 1. Replace.2. Faulty thermostat stage or broken wire 2. Replace.3. Stages not set for application 3. Reset thermostat setting for application.CompressorStaging IntervalsToo Short1. Thermostat control band not set properly 1. Set control band wider.2. Faulty water temperature sensor 2. Replace.3. Insufficient water flow4. Rapid load swings3. Adjust flow.4. Stabilize load.