Don't Be A Compressor Killer!
All mechanical equipment needs periodic service to keep it in the best operating condition. Good service can mean the difference between a few mechanical malfunctions or continuous problems.
Why Bother with Preventative Maintenance?
Refrigeration equipment will operate more efficiently and fewer hours per day. This translates into reduced electrical consumption…saving money
Extends the operating life of your equipment; therefore, delaying the substantial cost of equipment replacement
Reduces emergency service repair costs by resolving many potential problems prior to failure
Lowers equipment failure rate…Frequent equipment failure can hinder the success of your business
Savings in electrical consumption + reduced repair cost should more than offset the cost of implementing a refrigeration PM program
Don’t be a Compressor Killer: Know Causes to Prevent Repeat Failures
Every six months:
Tighten all electrical connections. Check for frayed wiring insulation and corroded terminals. Replace damaged wiring. Make certain all spade connections are tight.
Check all electrical components. Electrical contactors should be inspected closely for worn and pitted contact points. The points should be cleaned and polished. Check for any discoloration in the conductors, which may indicate a loose wire or a dangerous overcurrent condition. Any foreign material found in the contactor should be removed. Inspect the defrost timer motor. Clean the contact points and lubricate the gears of the clock. Make certain the entire clock mechanism rotates freely. Check all relays for worn points; replace relay if necessary. Check the electrical connections inside the compressor electrical box.
Check the operation of the control system. Check all pressure controls for proper operation and set points. Check the safety controls. Make certain the oil safety and high pressure controls are functioning. Check the operation of the room temperature thermostat. Make certain the liquid line solenoid valve closes completely and the compressor pumps down and cycles off.
Check the oil level in the compressor. The oil level should be at or between one-third and two-thirds of the sight glass. Check the operation of the crankcase heater.
Check the operation of the defrost controls. Under most conditions, the timer should initiate the defrost. Make certain the defrost termination temperature control stops the defrost cycle and allows the evaporator fans approximately 2 min of delay time before restart.
Check the condition of refrigerant line insulation. Open, torn, or waterlogged insulation provides little benefit to the system. If the insulation is in poor condition, replace it.
Check for the proper refrigerant level in the system. The liquid line sight glass should be clear and full of liquid refrigerant during normal operation. If not, find and repair the leak, then charge enough refrigerant into the system to maintain a clear sight glass.
Check the system superheat at the condensing unit. Suction superheat should be checked at the compressor as follows.
Measure the suction pressure at the suction service valve of the compressor and determine the saturation temperature corresponding to this pressure from a temperature-pressure chart.
Measure the suction temperature of the suction line about 1 ft. back from the compressor using an accurate thermometer.
Subtract the saturated temperature from the actual suction line temperature. The difference is superheat. Too low a suction superheat can result in liquid being returned to the compressor. This causes dilution of the oil and eventual failure of the bearings, rings or, possibly, valve failure. Too high a suction superheat will result in excessive discharge temperatures, which cause the oil to break down and result in piston ring wear and piston and cylinder wall damage. For maximum system capacity, suction superheat should be kept as low as practical. (The superheat at the compressor be no lower than 30°F.) If adjustments to the suction superheat need to be made, the expansion valve at the evaporator should be adjusted. Follow the manufacturer’s recommendations.
Check all capillary and super hose lines for signs of wear. Make certain all capillary and super hose lines are secure and do not rub against objects that can cause refrigerant leaks.
Replace all missing valve caps and unit covers.
