Viking VCSF036SS Service Book page 30

Component Testing
Component Description
Drier Drier is placed at post condenser loop
outlet and passes liquefied refrigerant to
capillary.
Desiccant (20) 8 x 12 4AXH - 7 M>S> -
Grams
Evaporator Activated when defrost thermostat,
defrost heater defrost timer, and freezer control
complete circuit through heater.
Thermostat Thermostat is in a series circuit with
terminal 2 of defrost timer, and defrost
heater. Circuit complete if evaporator fan
motor operates when cold.
Controls the circuit from freezer
thermostat through defrost terminator to
defrost heater. Opens and breaks circuit
when thermostat senses preset high
temperature.
30
Test Procedures
Drier must be changed every time the system is
opened for testing or compressor replacement.
NOTE: Drier used in R12 sealed system is not
interchangeable with drier used in R134a sealed
system. Always replace drier in R134a system with
correct part number.
Before opening refrigeration system, recover
HFC134a refrigerant for safe disposal.
1. Cut drier out of system using the following
procedure. Do not unbraze drier.
2. Applying heat to remove drier will drive moisture
into the system.
3. Score capillary tube close to drier and break.
4. Reform inlet tube to drier allowing enough space
for large tube cutter.
5. Cut circumference of drier 1 ¼" below condenser
inlet tube joint to drier.
6. Remove drier.
7. Apply heat trap paste on post condenser tubes
to protect grommets from high heat.
8. Unbraze remaining part of drier. Remove drier
from system.
9. Discard drier in safe place. Do not leave drier
with customer. If refrigerator is under warranty,
old drier must accompany warranty claim.
WARNING
To avoid death or severe personal injury,
cut drier at correct location. Cutting drier
at incorrect location will allow desiccant
beads to scatter. If spilled, completely
clean area of beads.
To check defrost system :
1. Thermocouple defrost thermostat and plug
refrigerator into wattmeter.
2. Turn into defrost mode. Wattmeter should read
specified watts (according to Technical Data
Sheet).
3. When defrost thermostat reaches specified
temperature ±5°F (see Technical Data Sheet),
thermostat should interrupt power to heater.
Test continuity across terminals.
With power off and evaporator coil below
freezing, thermostat should show continuity when
checked with ohmmeter. See Heater, evaporator
(defrost) section for additional tests.
After defrost thermostat opens, thermostat
remains open until end of defrost cycle and
refrigerator starts cooling again. Defrost
thermostat senses a preset low temperature and
resets (closes).
©2007 Viking Preferred Service