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Tough Test In Heating/Cooling Cycle
mid-positions is if all three tubes on the suction
side of the valve are hot after a few minutes of
running time.
Procedure For Changing Reversing Valve
Notice
FIRE HAZARD
The use of a torch requires extreme care and
proper judgment. Follow all safety recommended
precautions and protect surrounding areas with
readily available. Failure to follow this notice
could result in moderate to serious property
damage.
1. Install process tubes. Recover refrigerant
from the sealed system. PROPER
HANDLING OF RECOVERED
REFRIGERANT ACCORDING TO EPA
REGULATIONS IS REQUIRED.
2. Remove the solenoid coil from the reversing
valve. If the coil is to be reused, protect from
heat while changing valve.
3. Unbraze all lines from the reversing valve.
4. Clean all excess braze from all tubing so that
5. Remove the solenoid coil from the new valve.
6. Protect the new valve body from heat while
brazing with plastic heat sink (Thermo Trap)
or wrap valve body with wet rag.
7. Fit all lines into the new valve, and braze the
lines into new valve.
8. Once the sealed system is leak free, install
a solenoid coil on the new valve and charge
the sealed system by weighing in the proper
amount and type of refrigerant as shown on
the rating plate. Crimp the process tubes and
solder the ends shut. Do not leave Schrader
or piercing valves in the sealed system.
NOTE: When brazing a reversing valve into
the system, it is of extreme importance that the
temperature of the valve does not exceed 250°F
at any time.
Wrap the reversing valve with a large rag
saturated with water. "Re-wet" the rag and
thoroughly cool the valve after each brazing
operation of the four joints involved.
The wet rag around the reversing valve will
eliminate conduction of heat to the valve body
when brazing the line connection.
Overloads
The compressor is equipped with an external
or internal overload which senses both motor
amperage and winding temperature. High motor
temperature or amperage heats the overload
causing it to open, breaking the common circuit
within the compressor.
Heat generated within the compressor shell,
usually due to recycling of the motor, is slow
to dissipate. It may take anywhere from a few
minutes to several hours for the overload to reset.
Checking the Overload
External Overload 9, 12, 18 K Btus
With the power off, remove the leads from
compressor terminals. If the compressor is hot,
allow the overload to cool before starting check.
Using an ohmmeter, test continuity across the
terminals of the external overload. If there is not
continuity; this indicates that the overload is open
and must be replaced.
– 42 –
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Troubleshooting
