Service
Procedure
©2007 Viking Preferred Service
41
Replacement Service Compressor
HFC134a service compressors will be charged with
ester oil and pressurized with dry nitrogen. Before
replacement compressor is installed, pull out 1 rubber
plug. A pop from pressure release should be heard. If a
pop sound is not heard, do not use compressor. Positive
pressure in compressor is vital to keep moisture out of
ester oil. Do not leave compressor open to atmosphere
for more than 10 minutes.
Compressor Testing Procedures
WARNING
To avoid death or severe personal injury, never use
oxygen, air or acetylene for pressure testing or
clean out of refrigeration system. Use of oxygen, air,
or acetylene may result in violent explosion. Oxygen
may explode on contact with oil and acetylene will
spontaneously explode when under pressure.
Refer to Technical Data Sheet “Temperature
Relationship Chart” for operating watts, test points, and
temperature relationship test for unit being tested.
Temperature testing is accomplished by using 3 lead
thermocouple temperature tester in specific locations.
Test point T-1 is outlet on evaporator coil and T-2 is
inlet. Test point T-3 is suction tube temperature midway
between where armaflex ends and suction port of
compressor (approximately 12 inches from compressor).
Thermocouple tips should be attached securely to
specified locations.
Do not test during initial
pull down
. Allow one off cycle or
balanced temperature condition to occur before
proceeding with testing.
Refrigerator must operate minimum of 20 minutes after
thermocouples are installed.
Turn control to colder to obtain required on time.
Wattage reading must be recorded in conjunction with
temperature test to confirm proper operation.
Suction and head pressures are listed on “Temperature
and Relationship Chart”. Normally these are not required
for diagnosis but used for confirmation on systems which
have been opened.
Drier Replacement
Before opening refrigeration system, recover HFC134a
refrigerant for safe disposal.
Every time sealed HFC134a system is repaired, drier
filter must be replaced.
Cut drier out of system by completing the following
steps. Do not unbraze drier filter. Applying heat to
remove drier will drive moisture into system.
WARNING
To avoid risk of severe personal injury or death, cut
drier at correct location. Cutting drier at incorrect
location will allow desiccant beads to scatter.
Completely clean area of beads, if spilled.
1. Score capillary tube close to drier and break.
2. Reform inlet tube to drier allowing enough space for
large tube cutter.
3. Cut circumference of drier at 1-1/4”, below condenser
inlet tube joint to drier.
4. Remove drier.
5. Apply heat trap paste on post condenser tubes to
protect grommets from high heat.
6. Unbraze remaining part of drier. Remove drier from
system.
7. Discard drier in safe place. Do not leave drier with
customer. If refrigerator is under warranty, old drier
must accompany warranty claim.
