TEST OR INSPECTION
Disconnect power from the air conditioner before doing any maintenance work on the electrical
system. The voltage used can be lethal.
Check for loose electrical connections or faulty wiring.
Tighten loose connections. Replace bad wiring.
With lower panel and junction box cover removed, disconnect transformer leads from fuse block, XF1, terminals
2 and 3. Also disconnect transformer secondary leads from rectifier CR1, terminals 1 and 4. Apply 208 volts, ac,
to input leads which were disconnected from fuse block. Check voltage at secondary leads to be sure it is 28-30
Replace faulty transformer.
With lower panel and junction box cover off, disconnect rectifier leads from fuse block XF2, terminal 1, and from
terminal block TB2, terminal 6. Apply power to transformer to obtain 27-30 volts ac to rectifier, and check
disconnected leads to be sure that 24-28 volts dc is indicated. Positive (+) terminal is at XF2, terminal 1;
negative () terminal is at TB2, terminal 6.
Replace faulty rectifier.
With lower panel and junction box cover off, tag wires at K1 for identification, and disconnect. Apply 24-28 volts
dc to terminals X1 and X2 of relay K1, and check continuity of pairs A1-A2, B1-B2 and C1-C2. Each pair should
Replace faulty relay.
Disconnect transformer leads, and check continuity of H1-H2, X1-X2, H1-X1, H2-X2 and each lead to
transformer casing or common ground. H1-H2 and X1-X2 should show continuity; others should not Show
Replace transformer if continuity requirements are not met.
Disconnect leads of rectifier. Apply 28-30 volts ac to leads 1-4, and check leads 2-3 for 24-28 volt dc output.
Replace bad rectifier.
Disconnect compressor relay, K1. Apply 24-28 volts dc to terminals X1-X2, and check continuity of terminals
A1-A2, B1-B2, C1-C2. All should indicate continuity.
Replace faulty compressor start relay, K1.
With lower panel and junction box cover off, tag wires to time delay relay, K3, for identification and
disconnect. Apply 28 volts, dc, to primary terminals: positive (+) to terminal 1, and negative [-) to terminal 5.
Check continuity across secondary terminals 3 and 1 to see that contact is made within 25 6 seconds of
Replace bad time delay relay.
Disconnect plug, P4, from compressor receptacle. Using an ohmmeter or continuity tester, teat receptacle points
A-B, A-C, B-C, and D-E. Continuity should be indicated. Test points A, B and C to compress or casing or common
ground. No continuity should be indicated.
Replace compressor that does not meet continuity requirements.
7. COMPRESSOR STARTS BUT STOPS AT ONCE --"SHORTCYCLES"
Check sight-glass liquid indicator for bubbles while compressor is operating. If bubbles appear, check
refrigeration system for leaks.
Repair leaks, and add refrigerant until sight-glass is clear when compressor is running.
Connect pressure gauges to suction and discharge service valves. Check system pressures as indicated in the