Viking DDBF036LSS, Service Manual

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Service Procedure
30 ©2007 Viking Preferred Service
Service Equipment
Listed below is equipment needed for proper servicing of
HFC134a systems. Verify equipment is confirmed by
manufacturer as being compatible with HFC134a and
ester oil system.
•
Evacuation pump
Check with vacuum pump supplier to verify
equipment is compatible for HFC134a.
•
Leak detector
•
Flux
•
Sil-Fos
•
Silver solder
•
Dry nitrogen
99.5% minimum purity, with -40°F or lower dew
point
•
Crimp tool
•
Tube bender
•
Micron vacuum gauge
•
Heat trap paste
The following equipment must be exclusively used for
HFC134a.
•
Four-way manifold gauge set, with low loss hoses
•
Charging cylinder
•
Line piercing saddle valve
(Schroeder valves). Seals must be HFC134a and
ester oil compatible. Line piercing valves may be
used for diagnosis but are not suitable for
evacuation or charging, due to minute holes pierced
in tubing. Do not leave mechanical access valves on
system. Valves eventually will leak. Molecules of
HFC134a are smaller than other refrigerants and will
leak where other refrigerants would not.
•
Swagging tools
•
Flaring tools
•
Tubing cutter
•
Oil for swagging and flaring
•
Copper tubing
•
Process tube adaptor kit
•
ICI appliance grade HFC134a
Leak Testing
DANGER
TO AVOID RISK OF SERIOUS INJURY OR DEATH
FROM VIOLENT EXPLOSIONS, NEVER USE
OXYGEN OR ACETYLENE FOR PRESSURE
TESTING OR CLEAN OUT OF REFRIGERATION
SYSTEMS. FREE OXYGEN WILL EXPLODE ON
CONTACT WITH OIL. ACETYLENE WILL EXPLODE
SPONTANEOUSLY WHEN PUT UNDER PRESSURE.
It is important to check sealed system for refrigerant
leaks. Undetected leaks can lead to repeated service
calls and eventually result in system contamination,
restrictions, and premature compressor failure.
Refrigerant leaks are best detected with halide or
electronic leak detectors.
Testing Systems Containing a Refrigerant Charge
1. Stop unit operation (turn refrigerator off).
2. Holding leak detector exploring tube as close to
system tubing as possible, check all piping, joints,
and fittings.
NOTE:
Use soap suds on areas leak detector cannot
reach or reliably test.
Testing Systems Containing No Refrigerant Charge
1. Connect cylinder of nitrogen, through gauge
manifold, to process tube of compressor and liquid
line strainer.
2. Open valves on nitrogen cylinder and gauge
manifold. Allow pressure to build within sealed
system.
3. Check for leaks using soap suds.
If a leak is detected in a joint, do not to attempt to repair
by applying additional brazing material. Joint must be
disassembled, cleaned and rebrazed. Capture
refrigerant charge (if system is charged), unbraze joint,
clean all parts, then rebraze.
If leak is detected in tubing, replace tubing. If leak is
detected in either coil, replace faulty coil.