Friedrich Kuhl KCQ06A10A, Service & Parts Manual

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47 PB
R-410A SEALED SYSTEM REPAIRS
Sealed System Method of Charging/ Repairs
BURN HAZARD
Proper safety procedures must be followed,
and proper protective clothing must be worn
when working with a torch.
Failure to follow these procedures could
result in moderate or serious injury.
WARNING
FREEZE HAZARD
Proper safety procedures must be followed,
and proper protective clothing must be worn
when working with liquid refrigerant.
Failure to follow these procedures could
result in minor to moderate injury.
CAUTION
The acceptable method for charging the sealed system is the Weighed in Charge Method. The weighed in charge
method is applicable to all units. It is the preferred method to use, as it is the most accurate.
The weighed in method should always be used whenever a charge is removed from a unit such as for a leak
repair, compressor replacement, or when there is no refrigerant charge left in the unit. To charge by this method,
requires the following steps:
1. Install a piercing valve to remove refrigerant from the sealed system. (Piercing valve must be removed from
the system before recharging.)
2. Recover Refrigerant in accordance with EPA regulations.
3. Install a process tube to sealed system.
4. Make necessary repairs to system.
5. Evacuate system to 200 microns or less.
6. Weigh in refrigerant with the property quantity of R-410A refrigerant.
7. Start unit, and verify performance.
8. Crimp the process tube and solder the end shut.
COMPONENT TESTING
Hermetic Components Check
Metering Device - Capillary Tube Systems
All units are equipped with capillary tube metering devices. Checking for restricted capillary tubes.
1. Connect pressure gauges to unit.
2. Start the unit in the cooling mode. If after a few minutes of operation the pressures are normal, the check valve and the
cooling capillary are not restricted.
3. Switch the unit to the heating mode and observe the gauge readings after a few minutes running time. If the system
pressure is lower than normal, the heating capillary is restricted.
4. If the operating pressures are lower than normal in both the heating and cooling mode, the cooling capillary is restricted.
COOLING MODE
In the cooling mode of operation, liquid refrigerant from condenser (liquid line) enters the cooling check valve forcing the
heating check valve shut. The liquid refrigerant is directed into the liquid dryer after which the refrigerant is metered through
cooling capillary tubes to evaporator. (Note: liquid refrigerant will also be directed through the heating capillary tubes in a
continuous loop during the cooling mode).