5285473-UIM-E-1217
Johnson Controls Unitary Products
9
COMPRESSORS
The compressor used in this product is specifically designed to operate
with R-410A refrigerant and cannot be interchanged. Compressors
used in PCG6 models contain two internal bypass ports which enable
the compressor to operate at 67% part load capacity.
Check compressor rotation. If the scroll is misphased, change the
incoming line connection phasing to obtain the proper rotation.
The compressor uses polyolester (POE oil), Mobile 3MA POE. This oil
is extremely hydroscopic, meaning it absorbs water readily. POE oil can
absorb 15 times as much water as other oils designed for HCFC and
CFC refrigerants. If refrigerant circuit is opened, take all necessary pre-
cautions to avoid exposure of the oil to the atmosphere.
POE (polyolester) compressor lubricants are known to cause long term
damage to some synthetic roofing materials.
Procedures which risk oil leakage include, but are not limited to, com-
pressor replacement, repairing refrigerant leaks, replacing refrigerant
components such as filter drier, pressure switch, metering device or
coil.
Units are shipped with compressor mountings which are factory-
adjusted and ready for operation.
GAS HEAT
These two stage gas-fired heat sections have direct spark ignition.
GAS PIPING
Proper sizing of gas piping depends on the cubic feet per hour of gas
flow required, specific gravity of the gas and the length of run. National
Fuel Gas Code Z223.1 or CSA B149.1 should be followed in all cases
unless superseded by local codes or gas company requirements. Refer
to Tables 7 and 8.
The BTU content of the gas may differ with locality. The value should be
checked with the local gas utility.
Direct Drive Indoor Fan Data
Fan Size (Inch)
11 x 10
11 x 10
11 x 10
11 x 10
Type
Centrifugal
Centrifugal
Centrifugal
Centrifugal
Motor HP each
1/2
3/4
3/4
3/4
1
RPM
1200 Max
1200 Max
1200 Max
1200 Max
Frame size
48
48
48
48
Filters
Filter Size
B
B
B
B
Quantity - Size
Field-supplied external filters must be sized so as not to exceed 300 fpm air velocity through dis-
posable filters. For internal filter use, a filter rack kit is available. Consult the instructions supplied
with that kit for replacement filter sizes. Filter sizes: A=20x20, B=20x30.
Table 6:
Physical Data (Continued)
MODELS:
PCG6B36
PCG6B42
PCG6B48
PCG6B60
NOMINAL TONNAGE:
3.0
3.5
4.0
5.0
CAUTION
This system uses R-410A refrigerant which operates at higher pres-
sures than R-22. No other refrigerant may be used in this system.
CAUTION
Scroll compressors require proper rotation to operate properly. Fail-
ure to check and correct rotation may result in property damage.
NOTICE
Three-phase, scroll compressors operate in only one direction. If the
scroll is drawing low amperage, has similar suction and discharge
pressures, or is producing a high noise level, the scroll is misphased.
CAUTION
Do not leave the system open to the atmosphere. Unit damage could
occur due to moisture being absorbed by the POE oil in the system.
This type of oil is highly susceptible to moisture absorption
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CAUTION
Exposure, even if immediately cleaned up, may cause embrittlement
(leading to cracking) to occur in one year or more. When performing
any service that may risk exposure of compressor oil to the roof, take
precautions to protect roofing.
CAUTION
Do not loosen compressor mounting bolts.
NOTICE
There may be a local gas utility requirement specifying a minimum
diameter for gas piping. All units require a 1/2 inch pipe connection at
the gas valve.
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