SERVICE
Perform the procedures outlined below periodically, as indicated.
WARNING
To prevent injury or death due to electrical shock or contact with moving parts, open unit disconnect switch before ser- vicing unit.
IMPORTANT: When a compressor is removed from this unit, system refrigerant circuit oil will remain in the com- pressor. To avoid leakage of compressor oil, the refrigerant lines of the compressor must be sealed after it is removed.
IMPORTANT: All refrigerant discharged from this unit must be recovered without exception. Technicians must fol- low industry accepted guidelines and all local, state and fed- eral statutes for the recovery and disposal of refrigerants.
IMPORTANT: To avoid the release of refrigerant into the atmosphere, the refrigerant circuit of this unit must only be serviced by technicians who meet local, state and federal proficiency requirements.
Filters — Filters must be clean for maximum performance. Inspect filters every month under normal operating conditions. Replace when necessary.
IMPORTANT: Units should never be operated without a filter.
Water Coil — Keep all air out of the water coil. Check open loop systems to be sure the well head is not allowing air to infiltrate the water line. Always keep lines airtight.
Inspect heat exchangers regularly, and clean more frequent- ly if the unit is located in a “dirty” environment. Keep the heat exchanger full of water at all times. Open loop systems should have an inverted P trap placed in the discharge line to keep water in the heat exchanger during off cycles. Closed loop systems must have a minimum of 15 psig during the summer and 40 psig during the winter.
Check P trap frequently for proper operation.
CAUTION
To avoid fouled machinery and extensive unit
Condensate Drain Pans — Check condensate drain pans for algae growth twice a year. If algae growth is apparent, consult a water treatment specialist for proper chemical treat- ment. Applying an algaecide every three months will typically eliminate algae problems in most locations.
Refrigerant System — Verify air and water flow rates are at proper levels before servicing. To maintain sealed circuit- ry integrity, do not install service gages unless unit operation appears abnormal.
Check to see that unit is within the superheat and subcool- ing temperature ranges shown in Tables
Compressor — Conduct annual amperage checks to en- sure that amp draw is no more than 10% greater than indicated on the serial plate data.
Fan Motors — All units have lubricated fan motors. Fan motors should never be lubricated unless obvious, dry opera- tion is suspected. Periodic maintenance oiling is NOT recom- mended as it will result in dirt accumulating in the excess oil and cause eventual motor failure. Conduct annual dry opera- tion check and amperage check to ensure amp draw is no more than 10% greater than indicated on serial plate data.
Condensate Drain Cleaning — Clean the drain line and unit drain pan at the start of each cooling season. Check flow by pouring water into drain. Be sure trap is filled to main- tain an air seal.
Air Coil Cleaning — Remove dirt and debris from evap- orator coil as required by condition of the coil. Clean coil with a stiff brush, vacuum cleaner, or compressed air. Use a fin comb of the correct tooth spacing when straightening mashed or bent coil fins.
Condenser Cleaning —
Local water conditions may cause excessive fouling or pitting of tubes. Condenser tubes should therefore be cleaned at least once a year, or more often if the water is contaminated.
Proper water treatment can minimize tube fouling and pitting. If such conditions are anticipated, water treatment analysis is recommended. Refer to the Carrier System Design Manual, Part 5, for general water conditioning information.
CAUTION
Follow all safety codes. Wear safety glasses and rubber gloves when using inhibited hydrochloric acid solution. Observe and follow acid manufacturer’s instructions.
Clean condensers with an inhibited hydrochloric acid solu- tion. The acid can stain hands and clothing, damage concrete, and, without inhibitor, damage steel. Cover surroundings to guard against splashing. Vapors from vent pipe are not harmful, but take care to prevent liquid from being carried over by the gases.
Warm solution acts faster, but cold solution is just as effec- tive if applied for a longer period.
GRAVITY FLOW METHOD — Do not add solution faster than vent can exhaust the generated gases.
When condenser is full, allow solution to remain overnight, then drain condenser and flush with clean water. Follow acid manufacturer’s instructions. See Fig. 36.
FORCED CIRCULATION METHOD — Fully open vent pipe when filling condenser. The vent may be closed when condenser is full and pump is operating. See Fig. 37.
Regulate flow to condenser with a supply line valve. If pump is a non overloading type, the valve may be fully closed while pump is running.
For average scale deposit, allow solution to remain in con- denser overnight. For heavy scale deposit, allow 24 hours. Drain condenser and flush with clean water. Follow acid manu- facturer’s instructions.
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