Compressor Removal And Replacement; System Clean-Up After Burnout; Evacuation - 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

Compressor Removal and Replacement

Once it is determined that compressor has failed and the reason
established, compressor must be replaced.
CAUTION
!
PERSONAL INJURY HAZARD
Failure to follow this caution may result in personal injury.
Turn off all power to unit before proceeding. Wear safety glasses,
protective clothing, and gloves when handling refrigerant.
formed as a result of motor burnout can cause burns.
CAUTION
!
PERSONAL INJURY HAZARD
Failure to follow this caution may result in personal injury.
Wear safety glasses, protective clothing, and gloves when handling
refrigerant and when using brazing torch..
1. Shut off all power to unit.
2. Remove and recover all refrigerant from system until pressure
gauges read 0 psi. Use all service ports. Never open a system under
a vacuum to atmosphere. Break vacuum with dry nitrogen holding
charge first. Do not exceed 5 psig.
3. Disconnect electrical leads from compressor. Disconnect or remove
crankcase heater and remove compressor hold-down bolts.
4. Cut compressor from system with tubing cutter. Do not use brazing
torch for compressor removal. Oil vapor may ignite when
compressor is disconnected.
5. Scratch matching marks on stubs in old compressor. Make
corresponding marks on replacement compressor.
6. Use torch to remove stubs from old compressor and to reinstall
them in replacement compressor.
7. Use copper couplings to tie compressor back into system.
8. Replace filter drier, evacuate system, recharge, and check for
normal system operation.
CAUTION
!
UNIT DAMAGE HAZARD
Failure to follow this caution may result in equipment damage or
improper operation.
Do not leave system open to atmosphere. Compressor oil is highly
susceptible to moisture absorption.

System Clean-Up After Burnout

Some compressor electrical failures can cause motor to burn. When this
occurs, by-products of burn, which include sludge, carbon, and acids,
contaminate system. Test the oil for acidity using POE oil acid test to
determine burnout severity. If burnout is severe enough, system must be
cleaned before replacement compressor is installed. The 2 types of
motor burnout are classified as mild or severe.
In mild burnout, there is little or no detectable odor. Compressor oil is
clear or slightly discolored. An acid test of compressor oil will be
negative. This type of failure is treated the same as mechanical failure.
Liquid-line strainer should be removed and liquid-line filter drier
replaced.
In a severe burnout, there is a strong, pungent, rotten egg odor.
Compressor oil is very dark. Evidence of burning may be present in
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
tubing connected to compressor. An acid test of compressor oil will be
positive. Follow these additional steps:
1. TXV must be cleaned or replaced.
2. Drain any trapped oil from accumulator if used.
3. Remove and discard liquid-line strainer and filter drier.
4. After system is reassembled, install liquid and suction-line Puron
filter driers.
NOTE: On heat pumps, install suction line drier between compressor
and accumulator.
Acids
5. Operate system for 10 hr. Monitor pressure drop across drier. If
pressure drop exceeds 3 psig replace suction-line and liquid-line
filter driers. Be sure to purge system with dry nitrogen when
replacing filter driers. If suction line driers must be replaced, retest
pressure drop after additional 10 hours (run time). Continue to
monitor pressure drop across suction line filter drier. After 10 hr of
run time, remove suction-line filter drier and replace liquid-line
filter drier. Never leave suction-line filter drier in system longer
than 72 hr (run time).
6. Charge system. (See unit information plate.)
UNIT DAMAGE HAZARD
Failure to follow this caution may result in equipment damage or
improper operation.
Only suction line filter driers should be used for refrigerant and oil
clean up. Use of non-approved products could limit system life and
void unit warranty.

Evacuation

Proper evacuation of the system will remove non-condensibles and
assure a tight, dry system before charging. The two methods used to
evacuate a system are the deep vacuum method and the triple evacuation
method.
Deep Vacuum Method
The deep vacuum method requires a vacuum pump capable of pulling a
vacuum of 500 microns and a vacuum gauge capable of accurately
measuring this vacuum depth. The deep vacuum method is the most
positive way of assuring a system is free of air and moisture. (See
Fig. 35.)
5000
4500
4000
3500
3000
2500
2000
1500
1000
500
0
35
CAUTION
!
1 2 3 4 5 6
MINUTES
Fig. 35 – Deep Vacuum Graph
LEAK IN
SYSTEM
VACUUM TIGHT
TOO WET
TIGHT
DRY SYSTEM
7
A95424