9.2 Sealed Refrigeration System Repairs - Midea PD Series Manual

1. High amperage.
2. Low refrigerant charge.
3. Frequent recycling.
4. Dirty condenser.
9.1.5 Terminal overload – Test (compressor external type)
1. Remove overload.
2. Allow time for overload to reset before attempting to test.
3. Apply ohmmeter probes to terminals on overload wires. There should be continuity through
the overload.
9.1.6 Terminal overload (internal)
Some model compressors are equipped with an internal overload. The overload is embedded in
the motor windings to sense the winding temperature and/or current draw. The overload is
connected in series with the common motor terminal.
Should the internal temperature and/or current draw become excessive; the contacts in the overload will
open, turning off the compressor? The overload will automatically reset, but may require several hours
before the heat is dissipated.
9.1.7 Checking the internal overload
1. No power to unit, remove the leads from the compressor terminals.
2. Using an ohmmeter, test continuity between terminals C-S and C-R. If not continuous, the
compressor overload is open and the compressor must be replaced.

9.2 Sealed refrigeration system repairs

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9.2.1 Equipment require
1. Voltmeter
2. Ammeter
3. Ohmmeter
4. E.P.A. Approved Refrigerant Recovery System.
5. Vacuum Pump (capable of 200 microns or less vacuum.)
6. Acetylene Welder
7. Electronic Halogen Leak Detector (G.E. Type H-6 or equivalent.)
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