Dehydrating Sealed Refrigeration System; Leak Testing; Testing Systems Containing A Refrigerant Charge; Testing Systems Containing No Refrigerant Charge - Maytag MFI2266AES Service Manual

Service 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 10,000 ohm resistor before attempting
to service. Ensure all ground wires are connected before certifying unit as repaired and/or operational.

Dehydrating Sealed Refrigeration System

Moisture in a refrigerator sealed system exposed to
heat generated by the compressor and motor reacts
chemically with refrigerant and oil in the system and
forms corrosive hydrochloric and hydrofluoric acids.
These acids contribute to breakdown of motor winding
insulation and corrosion of compressor working parts,
causing compressor failure.
In addition, sludge, a residue of the chemical reaction,
coats all surfaces of sealed system, and will eventually
restrict refrigerant flow through capillary tube.
To dehydrate sealed system, evacuate system (see
paragraph Evacuation).

Leak Testing

!
To avoid risk of serious injury or death from violent
explosions, NEVER use oxygen or acetylene for
pressure testing or cleaning 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.
12
!
DANGER
16026312
WARNING

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.
©2006 Maytag Services