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AIR CONDITIONER - SYSTEMOPERATION
PAGE 621
REFERENCE
INFORMATION
PREVENTIVE MAINT NANCE
Owner/Operator Technician
Maintenance Maintenance
Maintenance Interval (months)
3 6 12
1. SystemMaintenance
o
Perform visual system inspection
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o
Perform manifold gauge check.
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o
Recover and Recycle System refrigerant
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Perform system evacuation and leak test
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Recharge system with correct refrigerant charge amount
2. Compressor and Belt Drive System
For systems that do not have A/C interlock, ( A/C compressor engages when the defrost mod is activated ) use the following procedure on a monthly basis.
Activate the A/C system for a minimum of 5 minutes every 30 days to circulate the refrigerant system lubrication and verify that the condenser fan ( s) (either
engine fan for radiator-mounted condensers or electric fans for remote-mounted condensers) engage and/or cycle on and off.
o
Check discharge line (warm/hot to touch)
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Check suction line (cool to touch)
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o
Inspect face of clutch hub for signs of slippage (heat discoloration)
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Check clutch working voltage and current draw (4 amps @ 12 volts / 2 amps @ 24 volts)
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o
Inspect shaft seal for presence of oil and dirt indicating leakage
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o
Confirm alignment of clutch pulley with crankshaft drive pulley (belt will show side wear)
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Inspect idler pulley for bearing wear (looseness)
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Inspect compressor belt for glazing or cracking
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Check belt tension (verify manufacturer’s specs in owners manual)
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3. Condenser
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Inspect tubes for obvious dents and oil stains/dirt indicating leakage
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Clean dirt and bugs from condenser fin area (more frequently under severe operating conditions)
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Inspect condition of fins (straighten as required)
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4. Receiver Drier (Filter)
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Note: Replace annually or any time refrigerant system is opened
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o
Check moisture indicator, either remote mounted or built into the drier
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(blue is OK while pink or white indicates moisture presence and replacement required)
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Check temperature of drier canister while running (warm to touch)
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5. Expansion Valve
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Check inlet (liquid) line from drier (warm to touch)
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Check refrigerant charge head for damage and leakage
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6. Evaporator
o
Clean dirt, bugs and airborne particulate from fin area
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Clean dirt, bugs and airborne particulate from the drain pan and drain hole
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Inspect drain pump (if present) and float for obstructions and operation
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7. Other Components
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Thermostat:
Check for proper operation
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o
Filters:
Inspect and clean or replace as needed
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(dirty filters can cause airflow restriction and premature blower failure)
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Pressure Switches:
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With manifold gauges installed, check refrigerant pressure switches for proper operation
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Water Valve :
Check water valve for proper operation
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(with control panel temp setting in full cold position, valve should be closed)