PREVENTIVE MAINTENANCE OF REFRIGERATION UNIT

1.0  PURPOSE:
         
    To describe a standard operating procedure for preventive maintenance of refrigeration unit.    
    
2.0    SCOPE:
    
    The standard operating procedure describes in detail the method of preventive maintenance of refrigeration unit.
    
3.0    RESPONSIBILITY:
    
    The responsibility of preventive  maintenance of  refrigeration  unit  lies  with the staff of rank not lower  than  the  junior  utility operator. 
        
The responsibility of preparing, reviewing  and approving  the  standard  operating procedure lies with the Manager - Maintenance, Head of Production and Head of QAD respectively.
    
4.0    METHOD:
    
4.1        Preventive maintenance shall be carried out for refrigeration unit as per the prescribed schedules and procedures.

    
4.2        Job instruction shall be followed for Monthly and Yearly preventive maintenance as per format Noxxxxx as shown in Annexure- I of SOP PREVENTIVE MAINTENANCE OF VARIOUS EQUIPMENT IN THE PLANT.during preventive maintenance of the equipment by the doer and checker.

    
4.3    Daily Preventive Maintenance checks :

4.3.1      Ensure the oil is in between ½ and 3/4th of the oil level indicating view glass. 

4.3.2      Inspect the previous day log book of the compressor and ensure that compressor is in good running condition.

4.3.3      If any abnormality is observed in parameters, rectify the problem.

4.3.4      Start the compressor and ensure that suction pressure, discharge pressure, oil pressure and control oil pressures parameters are within the working range.

4.3.5      Apply detergent solution and ensure that there is no leakage of gas from the compressor components and capillary tubes. If any leakages are found arrest them.

4.3.6      Clean refrigeration unit with dry cotton waste.

4.3.7     Ensure the Brine level in the tank is not less than 4.0 feet, and specific gravity is not less than 1.14, if found low add fresh brine.

4.3.8     Ensure that all coupling bolts of the compressor are tight, tighten the loose bolts if found.

4.3.9     Inspect the compressor coupling tyre.  If found damaged or worn out replace the tyre.

4.3.10    Record the readings in the Format no : xxxxx as shown in the Annexure-I.

4.4        Monthly Preventive Maintenance checks :

4.4.1      Clean the condenser tubes by brushing.

4.4.2      Start the compressor and pump down the compressor.

4.4.3      Open the gas strainer head and clean the strainer filter & the filter body with carbon tetrachloride. Refix the strainer head.

4.4.4    Open all liquid line valves, suction gun valve, discharge gun valve of the compressor.

4.4.5      Close the brine/chilled water tank outlet valves and open the primary pump strainer head.

4.4.6      Clean the strainer filter and the body with fresh water and remove the obstructions in the strainer filter, if any.  

4.4.7      Replace the strainer filter, if it is found damaged. Re-fix the strainer head. 

4.4.8      Open the brine/chilled water tank outlet valves.

4.5        Yearly checks.

4.5.1      Empty the brine/chilled water tanks and clean them.

4.5.2      Get the chiller shell and tubes descaled by an external agency. 

4.5.3    Get the compressor chiller and condenser shell thickness test done by an external agency.

4.5.4      Get the compressor overhauled by an external agency, if the compressor is not running with the full efficiency.

5.0        RECORDING

    The responsibility of recording Daily preventive maintenance schedule in the Format No: xxxxx lies with the staff of not less than the junior utility operator.

The responsibility of recording Monthly and yearly preventive maintenance in the preventive maintenance compliance report lies with the staff of rank not lower than the maintenance supervisor. 

Refrigeration unit, preventive maintenance, engineering