5168274-BIM-I-1121
14
Johnson Controls Ducted Systems
Compressors
The scroll compressor used in this product is specifically
designed to operate with R-410A Refrigerant and cannot be
interchanged.
The compressor also uses a polyolester (POE oil), Mobil 3MA
POE. This oil is extremely hygroscopic, meaning it absorbs water
readily. POE oil 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.
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,
compressor 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.
Filters
Two-inch filters are supplied with each unit. For XA-20 models,
the filter rack can be easily modified to accommodate four inch
filters. Filters must always be installed ahead of the evaporator
coil and must be kept clean or replaced with same size and
type. Dirty filters will reduce the capacity of the unit and will
result in frosted coils or safety shutdown. Minimum filter area
and required sizes are shown in Physical Data Table 7.
Power And Control Wiring
Field wiring to the unit, fuses, and disconnects must conform to
provisions of National Electrical Code (NEC), ANSI/NFPA No.
70 – Latest Edition (in U.S.A.), current Canadian Electrical
Code C221, and/or local ordinances. The unit must be
electrically grounded in accordance with NEC and CEC as
specified above and/or local codes.
Voltage tolerances which must be maintained at the
compressor terminals during starting and running conditions are
indicated on the unit Rating Plate and Table 1.
The internal wiring harnesses furnished with this unit are an
integral part of the design certified unit. Field alteration to
comply with electrical codes should not be required. If any of
the wire supplied with the unit must be replaced, replacement
wire must be of the type shown on the wiring diagram and the
same minimum gauge as the replaced wire.
A disconnect must be utilized for these units. Factory installed
disconnects are available. If installing a disconnect (field
supplied or Ducted Systems supplied accessory), refer to
Figure 1 for the recommended mounting location.
NOTE:
Since not all local codes allow the mounting of a
disconnect on the unit, please confirm compliance with
local code before mounting a disconnect on the unit.
Electrical line must be sized properly to carry the load. USE
COPPER CONDUCTORS ONLY. Each unit must be wired with
a separate branch circuit fed directly from the meter panel and
properly fused.
This system uses R-410A Refrigerant which operates at
higher pressures than R-22. No other refrigerant may be
used in this system.
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
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.
Do not loosen compressor mounting bolts.
Make sure that panel latches are properly positioned on
the unit to maintain an airtight seal.
208/230-3-60 unit control transformers are factory wired
for 230v power supply. Change tap on transformer for
208-3-60 operation. See unit wiring diagram.
Avoid damage to internal components if drilling holes for
disconnect mounting.
