Fisher & Paykel RX256DT4X1, Руководство по обслуживанию

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7 COMPONENT TESTING
Component Description Test Procedures
Compressor
When compressor electrical
circuit is energized, the start
winding current causes relay
to heat. After an amount of
starting time, the start winding
circuit turns off. The relay will
switch off the start winding
circuit even though
compressor has not started
(for example, when attempting
to restart after momentary
power interruption).
With “open” relay, compressor
will not start because there is
little or no current to start
windings. Overload protection
will open due to high locked
rotor run winding current.
With “shorted” relay or
capacitor, compressor will
start and overload protector
will quickly open due to high
current of combined run and
start windings.
With open or weak capacitor,
compressor will start and run
as normal but will consume
more energy.
Resistance test
1. Disconnect power to unit.
2. Discharge capacitor by shorting across terminals with a resistor
for 1 minute.
NOTE:
(Some compressors do not have a run capacitor.)
3. Remove leads from compressor terminals.
4. Set ohmmeter to lowest scale.
5. Check for resistance between:
Terminals “S” and “C”, start winding.
Terminals “R” and “C”, run winding.
If either compressor winding reads open (infinite or very high
resistance) or dead short (0 ohms), replace compressor.
Ground test
1. Disconnect power to refrigerator.
2. Discharge capacitor, if present, by shorting terminals through a
resistor.
3. Remove compressor leads and use an ohmmeter set on highest
scale.
4. Touch one lead to compressor body (clean point of contact) and
other probe to each compressor terminal.
•
If reading is obtained, compressor is grounded and must be
replaced.
Operation test
If voltage, capacitor, overload, and motor winding tests do not show
cause for failure, perform the following test:
1. Disconnect power to refrigerator.
2. Discharge capacitor by shorting capacitor terminals through a
resistor.
3. Remove leads from compressor terminals.
4. Wire a test cord to power switch.
5. Place time delayed fuse with UL rating equal to amp rating of
motor in test cord socket. (Refer to Technical Data Sheet.)
6. Remove overload and relay.
7. Connect start, common and run leads of test cord on
appropriate terminals of compressor.
8. Attach capacitor leads of test cord together. If capacitor is
used, attach capacitor lead to a known good capacitor of same
capacity.
9. Plug test cord into multimeter to determine start and run
wattage and to check for low voltage, which can also be a
source of trouble indications.
10. With power to multimeter, press start cord switch and release.
•
If compressor motor starts and draws normal wattage,
compressor is okay and trouble is in capacitor,
relay/overload, freezer temperature control, or elsewhere in
system.
•
If compressor does not start when direct wired, recover
refrigerant at high side. After refrigerant is recovered, repeat
compressor direct wire test. If compressor runs after
recovery but would not run when direct wired before
recovery, a restriction in sealed system is indicated.
•
If compressor does not run when wired direct after recovery,
replace faulty compressor.