Purpose of this instruction is to establish a standard procedure for the preventive maintenance of Cold Store Unit.
This will also serve as guideline for newly hired employees in the maintenance company which will be dealing with this type of air conditioning / refrigeration unit.
It is the responsibility of the air conditioning technician to conduct the correct preventive maintenance of Cold Store units to prevent system from breakdown, thus providing and ensuring the specified or target room temperature.
Maintenance technician should be competent enough to conduct the activity to avoid any damage and to provide the proper result.
The Supervisor and the Site Engineer should assure that this maintenance procedure will be followed.
Annual Compressor Checking
Check the operation of the crankcase heater; replace if found defective.
Check suction and discharge pressure reading.
Pressure should conform with specified pressure as stated in the equipment name plate and operation manual. Charge additional refrigerant if needed.
Check oil pressure using gauge manifold.
Check seals for any refrigerant leaks; replace if found any.
Check for undue noise and vibration. Rectify if found any.
Condenser Coil and Condenser Fan Motor Checking
Clean condenser coil by using approved chemical and by jet pump.
Check for undue noise and vibration. Rectify if found any.
Check insulation resistance of motor winding by using a multi-meter. Get line to line and line to ground resistance reading.
Control and Safety Devices Checking
Check solenoid valves proper operation. Replace if found defective.
Check H.P. cut-out switch for proper function. Replace if found defective.
Check L.P. cut-out switch for proper function. Replace if found defective.
Check pressure relief valve where applicable.
Check all thermostats for proper function.
Control Panel Maintenance
Clean and check all contactors for possible defects. Replace if found any.
Check timer relay and delay timer if available.
Check and tighten all terminals.
Use contact cleaner (CRC) if available.
General Point Checking
Check and record cold store temperature.
Check refrigerant pipe for possible damage. Replace if found any damage.
