TROUBLE SHOOTING CHART

SYMPTOM

 

CAUSES

CHECK & CORRECTIVE MEASURE

Unit works continuously, no sufficient

1.

Low suction pressure

1. Verify the reason & correct it (refer to symptom

cooling

 

 

 

for "low suction pressure").

 

2.

High discharge pressure

2.

Verify the reason and adjust the freon, if required.(refer

 

 

 

 

to symptom for "high discharge pressure").

 

3.

Less air quantity

3.

Refer to symptom for "blower works, less air".

 

4.

Cooling coil ices up

4. Determine the reason (refer to symptom for

 

 

 

 

"cooling coil ice up") & correct it.

 

5.

Second stage (If exists) not working

5. Set the thermostat to lower temperature (210C)/

 

 

 

 

or verify the reason.

 

6.

Serving large area

6. Check the design.

 

 

 

 

Unit not cooling properly during night

1.

Low ambient condition

1. Check and verify the ambient temperature.

time

2. Safety low pressure switch open due to low

2. Check the reason and correct it (refer to

 

 

suction pressure

 

symptom for "low suction pressure").

 

3.

Fan cycling (whenever applicable) setting low

3. Adjust the fan cycling.

 

4.

Thermostat setting too low

4. Adjust the thermostat setting.

 

5.

Cooling coil ices-up

5. Verify the reason and correct it (refer to

 

 

 

 

symptom for "cooling coil ice up").

 

6.

Less air quantity

6. Verify the reason and correct it (refer to

 

 

 

 

symptom for "blower works, less air").

 

 

 

Not sufficiently cooling during

1. High discharge pressure

1. Check and verify the reason (refer to symptom

daytime

2.

High thermostat setting

 

for "high discharge pressure").

 

2. Adjust thermostat.

 

3.

Serving large area

3. Check the design/unit selection.

 

4.

Less air quantity

4. Check and verify the reason (refer to symptom

 

5.

High ambient condition

 

for "blower works, less air").

 

5. Check the ambient condition.

 

6.

Dirty condenser

6. Clean it.

 

 

 

 

Cooling coil ices up

1.

Less freon

1. Check for gas leak & charge freon as required.

 

2.

Less air quantity

2. Determine the reason and correct it (refer to

 

3.

Dirty filter

 

symptom for "blower works, less air").

 

3.

Clean it.

 

4.

Dirty cooling coil

4.

Clean it.

 

 

 

 

 

Unit is not restarting (after a cut-off)

1.

Safety circuit open due to low pressure switch

1.

Rectify the reason of low suction pressure (refer

 

 

 

 

to symptom for "low suction pressure").

 

 

 

 

 

Unit is taking long time to restart

1.

Thermostat in cold location

1.

Shift the location as required.

Compressor goes lockout (pump

1. Imbalance freon

1. Check freon charge and confirm FLA.

down system)

2. Malfunctioning pumpdown solenoid valve

2. Check pumpdown solenoid valve operation.

 

 

 

 

Taking more time for the pumpdown

1. Leaky pumpdown solenoid valve

1.

Check pumpdown solenoid valve and replace it.

cycle, cooling coil ices up

 

 

 

 

Noisy unit

1.

Improper installation

1.Check and correct it properly.

 

2.

Improper vibration isolators

2.

Check and correct it properly.

 

3. Loose parts or mountings

3. Check and tighten.

 

4.

Tubing rattle

4. Tighten the pipe support.

 

5.

Bent fan blade causes vibration

5. Check the balance, alignment, bracket, etc.

 

 

 

 

Correct it/replace it.

 

6.

Defective bearings

6. Replace the motor.

 

7.

Belt tension is high

7.

Adjust belt tension.

 

8.

Blower motor pulley is not aligned

8.

Align pulley.

Unit operational noise listening inside

1.

Improper installation

1.

Check and correct it.

the building

2.

Improper vibration isolators

2.

Check and correct it.

 

3.

Abnormal noise in the unit

3.

Verify the reason of noisy unit & correct it.

 

4.

Unit too close to the slab/wall openings

4. Verify the design/Relocate the unit if necessary.

 

5.

Duct design (high static)

5. Check & verify the design.

 

6.

Wooden packing beneath the compressor is not removed

6. Remove wooden packing (if any).

Compressor not working

1.

Low voltage

1. Rectify the reason & correct it.

 

2. Single phase failure

2.

Check the compressor amperage each phase.

 

3.

Burned wirings

3. Check and correct it.

 

4. Overload protector open

4. Check and verify the reason.

 

5.

Defective contactor

5. Check and replace it.

 

6. Burned compressor motor winding

6. Check and replace it.

 

7. Damaged (stuck) compressor

7. Check and replace it.

Circuit breaker of the unit trips

1.

Burned wirings

1. Check and correct the wiring.

 

2. Grounded wirings

2. Check meggar test.

 

3.

Faulty field wiring

3. Check wiring against diagram.

 

4.

Grounded compressor/blower motor

4. Replace it, if required.

 

5.

Undersize circuit breaker

5.

Check the circuit breaker ratings.

 

 

 

 

 

21

Page 22
Image 22
Cooline PT360, PT036 manual Unit works continuously, no sufficient Low suction pressure