1183746-UIM-B-0215
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.
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 single stage gas-fired heaters 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unless superseded by local codes or gas company requirements.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.
GAS CONNECTION
The gas supply line should be routed through the 1-5/8" hole located on
the right side of the unit. See Figure 3 for the location. The unit is sup-
plied with a rubber grommet that fits in this hole and is used to seal
around the gas pipe. THIS GROMMET MUST BE INSTALLED IN
ORDER TO PREVENT LEAKAGE OF AIR AND WATER INTO THE
HEATING/CONTROLS COMPARTMENT.
Gas piping requirements:
1. A drip leg and a ground joint union must be installed in the gas pip-
ing.
2. When required by local codes, a manual shut-off valve may have to
be installed outside of the unit.
3. Use wrought iron or steel pipe for all gas lines. Pipe thread sealant
should be applied sparingly to male threads only.
4. All piping should be cleaned of dirt and scale by hammering on the
outside of the pipe and blowing out the loose dirt and scale. Before
initial start-up, be sure that all of the gas lines external to the unit
have been purged of air.
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
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
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.
Table 7: Natural Gas Pipe Sizing Chart
1
1. Maximum capacity of pipe in cubic feet of gas per hour (based upon a pres-
sure drop of 0.3 inch water column and 0.6 specific gravity gas).
Length
In Feet
Nominal Inches Iron Pipe Size
1/2” 3/4” 1” 1-1/4”
10 132 278 520 1,050
20 92 190 350 730
30 73 152 285 590
40 63 130 245 500
50 56 115 215 440
60 50 105 195 400
70 46 96 180 370
80 43 90 170 350
90 40 84 160 320
100 38 79 150 305
Table 8: Propane (LP) Gas Pipe Sizing Chart
1
1. Maximum capacity of pipe in thousands of BTU per hour (based upon a
pressure drop of 0.5 inch water column).
Length
In Feet
Nominal Inches Iron Pipe Size
1/2” 3/4” 1” 1-1/4”
10 275 567 1071 2,205
20 189 393 732 1496
30 152 315 590 1212
40 129 267 504 1039
50 114 237 448 913
60 103 217 409 834
70 96 196 378 771
80 89 185 346 724
90 83 173 322 677
100 78 162 307 630
CAUTION
If flexible stainless steel tubing is allowed by the authority having
jurisdiction, wrought iron or steel pipe must be installed at the gas
valve and extend a minimum of two (2) inches outside of the unit cas-
ing.
WARNING
Natural gas may contain some propane. Propane being an excellent
solvent, will quickly dissolve white lead or most standard commercial
compounds. Therefore, a special pipe thread sealant must be
applied when wrought iron or steel pipe is used. Shellac base com-
pounds such as gaskoloc or stalastic, and compounds such as Rec-
torseal # 5, Clyde’s or John Crane may be used.
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