Amana ANX, Service And Troubleshooting

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SERVICING
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6. If ground is indicated, replace the compressor. The
resistance reading should be infinity. If there is any
reading on meter, there is some continuity to ground and
compressor should be considered defective.
Compressor Ground Test
WARNING
Damage can occur to the glass embedded
terminals if the leads are not properly
removed. This can result in terminal and hot oil
discharging.
Unloader Test Procedure
(2 Stage Compressors Only)
A nominal 24-volt direct current coil activates the
compressor internal unloader solenoid. The input control
circuit voltage must be 18 to 28 volt ac. (remove) The
coil power requirement is 5 VA. The external electrical
connection is made with a molded plug assembly. This plug
contains a full wave rectifier to supply direct current to the
unloader coil. The measured DC voltage at the connectors
in the plug should be 15 to 27 volt dc.
Unloader Test Procedure
If it is suspected that the unloader is not working, the
following methods may be used to verify operation.
1. Operate the system and measure compressor amperage.
Cycle the unloader ON and OFF at 10 second intervals.
The compressor amperage should increase when
switching from part-load to full-load and decrease when
switching from full-load to part-load. The percent change
depends on the operating conditions and voltage, but
should be at least 25 percent.
2. If step one does not give the expected results, shut unit
off. Apply 18 to 28 volt ac to the unloader molded plug
leads and listen for a click as the solenoid pulls in. Remove
power and listen for another click as the unloader returns
to its original position.
3. If clicks can’t be heard, shut off power to the unit and
remove the control circuit molded plug from the compressor
and measure the unloader coil resistance (connections on
the compressor). The solenoid coil should have continuity
and not be grounded or have infinite resistance. If the coil
resistance is infinite, zero, or grounded, the compressor
must be replaced.
4. Next check the molded plug.
a. Voltage check: Apply control voltage to the plug wires (18
to 28 volt ac). The measured dc voltage at the female
connectors in the plug should be around 15 to 27 vdc.
b. Resistance check: Measure the resistance from the
end of one molded plug lead to either of the two female
connectors in the plug. One of the connectors should
read close to zero ohms while the other should read
infinity. Repeat with other wire. The same female
connector as before should read zero while the other
connector again reads infinity. Reverse polarity on the
ohmmeter leads and repeat. The female connector that
read infinity previously should now read close to zero
ohms.
Replace plug if either of these test methods doesn’t show
the desired results.
Operation Test
If the voltage, capacitor, overload and motor winding test
fail to show the cause for failure:
WARNING
High Voltage!
Disconnect all power before servicing
or installing. Multiple power sources
may be present. Failure to do so may
cause property damage, personal injury
or death.
1. Remove unit wiring from disconnect switch and wire a test
cord to the disconnect switch.
NOTE: The wire size of the test cord must equal the
line wire size and the fuse must be of the proper size
and type.
2. With the protective terminal cover in place, use the three
leads to the compressor terminals that were disconnected
at the nearest point to the compressor and connect the
common, start and run clips to the respective leads.
3. Connect good capacitors of the right MFD and voltage
rating into the circuit as shown.
4. With power ON, close the switch.