Viking VCBB360R Service Manual page 24

Component Testing
Component
Compressor When compressor electrical circuit is
energized, the start winding current
causes relay to heat. After an amount 2. Discharge capacitor by shorting across terminals with a
of starting time, start winding circuit
turns off. Relay will switch off start
winding circuit even though
or has not started (for example, when 5. Check for resistance between
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.
Description
Resistance test
1. Disconnect power to unit.
3. Remove leads from compressor terminals.
s- 4. Set ohmmeter to lowest scale.
compres
1. Disconnect power to refrigerator.
2. Discharge capacitor be shorting terminals through a
3. Remove compressor leads and use an ohmmeter set on
4. Touch one lead to compressor body (clean point of
If voltage, capacitor, overload, and motor winding test
good, perform the following test.
1.
2.
3.
4.
5.
6.
7.
8.
24
resistor for 1 minute.
Terminals "S" and "C"
Terminals "R" and "C"
If either compressor winding reads open (infinite or very
high resistance) or dead short (0 ohms), replace
compressor.
Ground Test
resistor for 1 minute.
highest scale.
contact
and the other probe to each compressor terminal. If a
reading is obtained, compressor is grounded and must be
Operation Test
Disconnect power to refrigerator using power switch.
Discharge capacitor by shorting capacitor terminals
through a resistor for 1 minute.
Remove leads from compressor terminals.
Wire a test cord to power switch.
Place time delayed fuse with UL rating equal to amp
rating of motor in test cord socket.
Remove overload and relay.
Connect start, common and run leads of test cord on
appropriate terminals of compressor.
Attach capacitor leads of test cord together. If
capacitor is used, attach capacitor to a known good
capacitor of
Test Procedures