Refrigeration System Repair; Leak Detection; Coil Removal - Bryant Base Series Application Manual And Service Manual

Residential Air Conditioners and Heat Pumps Using R-22 and Puron® Refrigerant: Application Guideline and Service Manual

REFRIGERATION SYSTEM REPAIR

Leak Detection

New installations should be checked for leaks prior to complete
charging. If a system has lost all or most of its charge, system must be
pressurized again to approximately 150 psi minimum and 375 psi
maximum. This can be done by adding refrigerant using normal charging
procedures or by pressurizing system with nitrogen (less expensive than
refrigerant). Nitrogen also leaks faster than refrigerants.
cannot, however, be detected by an electronic leak detector. (See
Fig. 29.)
Fig. 29 – Electronic Leak Detection
WARNING
!
PERSONAL INJURY AND UNIT DAMAGE HAZARD
Failure to follow this warning could result in personal injury or death.
Due to the high pressure of nitrogen, it should never be used without a
pressure regulator on the tank.
Assuming that a system is pressurized with either all refrigerant or a
mixture of nitrogen and refrigerant, leaks in the system can be found
with an electronic leak detector that is capable of detecting specific
refrigerants.
If system has been operating for some time, first check for a leak
visually. Since refrigerant carries a small quantity of oil, traces of oil at
any joint or connection is an indication that refrigerant is leaking at that
point.
A simple and inexpensive method of testing for leaks is to use soap
bubbles. (See Fig. 30) Any solution of water and soap may be used. Soap
solution is applied to all joints and connections in system. A small
pinhole leak is located by tracing bubbles in soap solution around leak. If
the leak is very small, several minutes may pass before a bubble will
form. Popular commercial leak detection solutions give better,
longer-lasting bubbles and more accurate results than plain soapy water.
The bubble solution must be removed from the tubing and fittings after
checking for leaks as some solutions may corrode the metal.
LEAK
DETECTOR
SOLUTION
Fig. 30 – Bubble Leak Detection
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
You may use an electronic leak detector designed for specific refrigerant
to check for leaks (See
and easiest method for checking leaks. There are various types of
electronic leak detectors. Check with manufacturer of equipment for
suitability. Generally speaking, they are portable, lightweight, and
consist of a box with several switches and a probe or sniffer. Detector is
turned on and probe is passed around all fittings and connections in
system. Leak is detected by either the movement of a pointer on detector
Nitrogen
dial, a buzzing sound, or a light.
In all instances when a leak is found, system charge must be recovered
and leak repaired before final charging and operation. After leak testing
or leak is repaired, replace liquid line filter drier, evacuate system, and
recharge with correct refrigerant quantity.

Coil Removal

Coils are easy to remove if required for compressor removal, or to
replace coil.
1. Shut off all power to unit.
2. Recover refrigerant from system through service valves.
3. Break vacuum with nitrogen.
4. Remove top cover. (See Remove Top Cover in Cabinet section of
the manual.)
5. Remove screws in base pan to coil grille.
A95422
6. Remove coil grille from unit.
7. Remove screws on corner post holding coil tube sheet.
FIRE HAZARD
Failure to follow this warning could result in personal injury or
equipment damage.
Cut tubing to reduce possibility of personal injury and fire.
8. Use a small tubing cutter to cut the liquid and vapor lines at both
side of the coil. Cut in convenient location for easy reassembly with
copper slip couplings.
9. Lift coil vertically from basepan and carefully place aside.
10. Reverse procedure to reinstall coil.
11. Replace filter drier, evacuate system, recharge, and check for
normal systems operation.
A95423
33
Fig. 29). This unquestionably is the most efficient
WARNING
!