Component Testing Procedures - Viking DFRD144 Service Manual

Component Testing Procedures

To avoid risk of electrical shock, personal injury, or death, disconnect electrical power source to unit, unless test
procedures require power to be connected. Discharge capacitor through a resistor before attempting to service.
Ensure all ground wires are connected before certifying unit as repaired and/or operational.
Component
Perform visual check of frost pattern on
evaporator plate......................................
Evaporator Plate
1.
2.
3.
4.
5.
•
Compressor
•
1.
2.
3.
4.
Run Capacitor
(some models)
Perform visual check to ensure that
sufficient airflow passes over the
condenser ...............................................
Condenser
16
Test Procedure
Disconnect power to unit.
Discharge run capacitor by shorting
across terminals with a resistor 1
minute (some models)
Remove leads from compressor
terminals.
Set ohmmeter to lowest scale.
Check for resistance/continuity
across the following:
Start winding/Run winding (See
Compressor section) ........................
Run/Common/Start terminals to
compressor housing .........................
Disconnect power to unit.
Remove capacitor from circuit.
Discharge capacitor by shorting
terminals with a resistor for 1
minute.
Check resistance across capacitor
terminals with ohmmeter set to kΩ
scale .................................................
• A uniform frost pattern indicates a satisfactory
flow of refrigerant through evaporator.
• An incomplete or uneven frost pattern indicates
a possible blockage in evaporator or a low
refrigerant charge in the system.
• If run winding or start winding reads high to
infinite resistance (open), replace compressor.
• If run winding or start winding reads no
resistance (dead short), replace compressor.
• If continuity to ground is found in any of the
three terminals, replace compressor.
• Good - needle swings to zero and slowly
moves back to infinity.
• Open - needle does not move. Replace run
capacitor.
• Shorted - needle moves to zero and stays.
Replace run capacitor.
• High resistance leak - needle jumps to
zero and then moves back to constant high
resistance (not infinity). Replace run capacitor.
• Ensure that there is no blockage of the intake
or exhaust side of condenser.
• Ensure that condenser is free of dust, lint, or
hair that may hinder heat transfer.
SMR-0003
Service Action
© Viking Range Corporation