Refrigeration System; Refrigerant; Servicing Systems On Roofs With Synthetic Materials - 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
Ground Circuit
To determine if a wire has broken or come in direct contact with shell,
causing a direct short to ground, follow these steps:
1. Allow crankcase heaters to remain on for several hours before
checking motor to ensure windings are not saturated with

refrigerant.

2. Using an ohmmeter on R X 10,000 ohm scale or megohmmeter
(follow manufacturer's instructions).
3. Be sure all power is off.
4. Discharge all capacitors.
5. Remove wires from terminals C, S, and R.
6. Place one meter probe on ground or on compressor shell. Make a
good metal-to-metal contact. Place other probe on terminals C, S,
and R in sequence.
7. Note meter scale.
8. If reading of 0 or low resistance is obtained, motor is grounded.
Replace compressor.
Compressor resistance to ground should not be less than 1000 ohms per
volt of operating voltage.
Example:
230 volts X 1000 ohms/volt = 230,000 ohms minimum.
Short Circuit
To determine if any wires within windings have broken through their
insulation and made contact with other wires, thereby shorting all or part
of the winding(s), be sure the following conditions are met.
1. Correct motor winding resistances must be known before testing,
either from previous
specifications.
2. Temperature of windings must be as specified, usually about 70°F.
3. Resistance measuring instrument must have an accuracy within ±
5-10 percent. This requires an accurate ohmmeter such as a
Wheatstone bridge or null balance-type instrument.
4. Motor must be dry or free from direct contact with liquid
refrigerant.
Make This Critical Test
(Not advisable unless above conditions are met)
1. Be sure all power is off.
2. Discharge all capacitors.
3. Remove wires from terminals C, S, and R.
4. Place instrument probes together and determine probe and lead wire
resistance.
5. Check resistance readings from C-R, C-S, and R-S.
6. Subtract instrument probe and lead resistance from each reading.
If any reading is within ±20 percent of known resistance, motor is
probably normal. Usually a considerable difference in reading is noted if
a turn-to-turn short is present.
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
readings or from manufacturer's

REFRIGERATION SYSTEM

Refrigerant
!
UNIT OPERATION AND SAFETY HAZARD
Failure to follow this warning could result in personal injury or
equipment damage.
Puron refrigerant which has higher pressures than R-22 and other
refrigerants. No other refrigerant may be used in this system. Gauge set,
hoses, and recovery system must be designed to handle Puron. If you
are unsure consult the equipment manufacturer.
!
UNIT DAMAGE HAZARD
Failure to follow this caution may result in equipment damage or
improper operation.
The compressor in a Puron system uses a polyol ester (POE) oil. This
oil is extremely hygroscopic, meaning it absorbs water readily. POE
oils can absorb 15 times as much water as other oils designed for HCFC
and CFC refrigerants. Take all necessary precautions to avoid exposure
of the oil to the atmosphere.
In an air conditioning and heat pump system, refrigerant transfers heat
from one place to another. The condenser is the outdoor coil in the
cooling mode and the evaporator is the indoor coil.
In a heat pump, the condenser is the indoor coil in the heating mode and
the evaporator is the outdoor coil.
In the typical air conditioning mode, compressed hot gas leaves the
compressor and enters the condensing coil. As gas passes through the
condenser coil, it rejects heat and condenses into liquid. The liquid
leaves condensing unit through liquid line and enters metering device at
evaporator coil. As it passes through metering device, it becomes a
gas-liquid mixture. As it passes through indoor coil, it absorbs heat and
the refrigerant moves to the compressor and is again compressed to hot
gas, and cycle repeats.
Servicing Systems on Roofs With Synthetic
Materials
POE (polyol ester) compressor lubricants are known to cause long term
damage to some synthetic roofing materials. Exposure, even if
immediately cleaned up, may cause embrittlement (leading to cracking)
to occur in one year or more. When performing any service which may
risk exposure of compressor oil to the roof, take appropriate precautions
to protect roofing. Procedures which risk oil leakage include but are not
limited to compressor replacement, repairing refrigerants leaks,
replacing refrigerant components such as filter drier, pressure switch,
metering device, coil, accumulator, or reversing valve.
Synthetic Roof Precautionary Procedure
1. Cover extended roof working area with an impermeable
polyethylene (plastic) drop cloth or tarp. Cover an approximate 10
x 10 ft area.
2. Cover area in front of the unit service panel with a terry cloth shop
towel to absorb lubricant spills and prevent run-offs, and protect
drop cloth from tears caused by tools or components.
3. Place terry cloth shop towel inside unit immediately under
component(s) to be serviced and prevent lubricant run-offs through
the louvered openings in the base pan.
4. Perform required service.
5. Remove and dispose of any oil contaminated material per local
codes.
25
WARNING
CAUTION