REFRIGERATION-TROUBLE SHOOTING

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REFRIGERATION TROUBLE SHOOTING

 

Trouble shooting in refrigeration and air conditioning tells

the faults of a system. Few precautions will make the system

trouble free.

  1. UNIT DOES NOT RUN AT ALL
  2. REFRIGERATION UNIT RUNS BUT NO COOLING
  3. LESS COOLING BUT THE UNIT RUNS
  4.  CONTINUOUSLY RUNNING OF THE UNIT
  5.  TRIPPING OF THE UNIT TAKES PLACE  TIME AND AGAIN
  6. NOISY UNIT

COOLING UNIT NOT RUNNING

Sr. No.

Cause

Check and remedy

1.
No electric power supply
Test with test lamp for the availability of power. If not, write the complaint.
2.
Discontinuity in circuit
Check for continuity and do the necessary repair
3.
Fuse blown
Observe for fuse blown, if fuse is blown, then replace the broken fuse.
4.
Overload protector burnt out
 overload protector, if blown, replace the overload protector.
5.
Too low voltage
Measure for low voltage. If it is there, close the unit and write the complaint with the supply complaint office.
6.
Thermostatic is in off position
See for the thermostat for proper setting. If not, set it the right setting.
7.
Relay defective
Heck for relay. Start the unit without relay. If starts, replace the relay.
8.
Stuck compressor
Compressor may be  stuck. Start the unit without relay. If it does not start, then open the hermetically sealed unit and do the necessary repair.
9.
Burnt motor
There may be  no continuity in motor winding, if it is not there, get it rewound.

 NO COOLING BUT UNIT IS WORKING

Sr. No.

Cause

Testing and remedy

1.
No refrigerant in the cooling unit
Run the unit. Touch condenser for hotness and evaporator for coldness. If results are found, check the unit for leakage first, repair for leakage if found. And only then charge the refrigerant into the unit.
2.
Filter in Drier cum filter has choked
Pinch off the tube at entrance and exit of the filter. Take out filter and replace it by a new filter.

REFRIGERATION UNIT RUNNING BUT NOT GIVING THE DESIRED COOLING

Sr. No.

Cause

Check and remedy

1.
Improper Thermostat setting
Check for setting and do the necessary correct adjustment.
2.
Shortage of refrigerant in the unit
Run the unit. Check for frost on evaporator because of low pressure. Also check for condenser hotness. If it is less hot, then charge more refrigerant into the unit after insuring no leakage.
3.
Excess of refrigerant in the unit
See for sweating on suction pipe and condenser for excessively hotness. If it is there, then purge some refrigerant till the required conditions are achieved
4.
Insufficient  condensation
There is dust on condenser tubes. Check for fan speed. Proper cooling is not there. Clean the condenser tubes and do the necessary repair of the blower if necessary.
5.
Compressor working inefficiently
Observe for frosting on the evaporator tubes, cold condenser and warm suction line will tell about the inefficient working of the compressor. Open the unit and do the necessary repair of the compressor.
6.
Tripping via overload protector
Test the overload protector for its loose connections. Reduce cooling load on the machine or check by replacing the overload protector.
7.
Wrong setting of thermostat
Observe if the machine is stopping before reaching the required temperature or machine is not stopping at all. Check the thermostat and do the right setting of the thermostat.
8.
The walls, roofs and bottom are poorly insulated
Heat is constantly entering through the entire structure and it is appearing that the machine is not giving the desired cooling. Fill the required insulation where it is less.
9.
Door not properly closed
Check the lining in the door for its tightness. Check if the door is not tightly closed. Check for something which is not allowing the door to be tightly closed. Do the necessary repair or replacement to ensure tight closing of the door.
10.
Inside light is always on
Test the door switch. Check its operation by opening and closing the door time and again. If defective, do the necessary replacement.

UNIT RUNS CONTINUOUSLY

Sr. No.

Possible cause

Check and remedy

1.
Improper refrigeration
Check for shortage/excess of refrigerant, poor condensation, choking in the refrigeration cycle, inefficient compressor, door leakage etc. and do the necessary repair or replacement
2.
Adjustment of thermostat at very low temperature
Note the thermostat setting and do the necessary adjustment or repair it or replace it.

 ICE FREEZES INSIDE BUT DOES NOT COOL THE PRODUCTS INSIDE PROPERLY

Sr. No.

Possible cause

Check and remedy

1.
Poor circulation of air inside
 Insure refrigerator shelves are over crowded. If so, remove or adjust products to be cooled to permit better circulation of air.
2.
Inside light is always on
Observe door switch and its operation with the door. Repair it or replace it.
3.
Excessive frosting on the cooling coil
There is no freezing on evaporator coil. If it is there, switch off the machine to melt ice from the evaporator coil.
4.
Leakage of air in the door
 Door lining should be checked. Repair it or replace it to make sure that there is no leakage of cooling from the door.
5.
Poor insulation of the cooling unit
Fill the unit with proper insulation.
 

TRIPPING UNIT VERY FREQUENTLY

Sr. No.

Possible cause

Check and remedy

1.
Dust on condenser
There should be no dust on condenser, If it is there, wash it with water and clean with a soft cloth.
2.
Frequent voltage fluctuations
Are there  voltage fluctuations? Adjust it if possible otherwise close the unit for sometime till voltage is fluctuating.
3.
Defective relay
 If the relay is defective, then repair it if possible or replace it.
4.
Choking in the system
Improper cooling and cold condenser is the indication for choking. If the observation is yes, then replace the filter cum drier.
5.
Overcharging of refrigerant
Water on suction line is an indication of overcharging. If it is found, purge some refrigerant from the system.
6.
Motor winding are week
Check motor winding. If not proper, then get it rewound.

INTERIOR LIGHT DEFECTIVE

Sr. No.

Possible cause

Check and remedy

1.
Always Light is  on
Check door switch operation. If found defective, repair it or replace it.
2.
Light is always on
 Door switch electric circuit be checked. If found defective, repair it or replace it.

NOISY UNIT

Sr. No.

Possible cause

Check and remedy

1.
Improper leveling of the cooling unit
Check the leveling of the unit. If found, adjust the base screws to level it.
2.
Food stuff loosely placed inside
Check for food stuff. If found loosely placed, place it properly
3.
Noise inside the condensing unit
Compressor motor assembly not properly mounted on springs. Check if found noise inside, cut welding of the sealed unit and do the necessary repair or replacement.
4.
Loose condenser coil
Check for loose condenser coil. If found, do the necessary repair or replacement.