York Sun Select YV28, Manual

Page: 29 / 110

Ductwork
You must design and size ductwork according to
the methods in Manual D of the Air Conditioning
Contractors of America (ACCA) or as recommended
by any other recognized authority such as ASHRAE
or SMACNA. When you design the duct system,
apply the following recommendations.
• Use a closed return duct system. This does not
preclude the use of economizers or outdoor
fresh air intake.
• Make the supply and return air duct
connections at the unit with flexible joints to
minimize noise.
• Design the supply and return air duct systems
for the CFM and static pressure requirements
of the job. Do not size them to match the
dimensions of the duct connections on the
unit.
See the Duct openings section for information on
side and bottom air duct openings.
Note: In Canada, it is recommended that the
outlet duct be provided with a removable
access panel. It is recommended that this
opening is accessible when the unit is installed
in service, and of a size such that smoke or
reflected light may be observed inside the
casing to indicate the presence of leaks in the
heat exchanger. You must attach the cover in a
manner adequate to prevent leakage.
Placing the equipment over a
Trane curb
When using this product to directly replace select
Trane branded equipment, the placement of the
unit on the existing Trane roof curb is required to
follow the manufacturer’s placement guidelines.
Each of the kits below will include installation
instructions particular to that kit.
When replacing Trane units that are 27.5 tons,
30 tons, or 35 tons with high heat gas heat the roof
curb block off kit, 1BP0405 , is required to cover an
opening in the remaining Trane roof curb. This kit
is only applicable in replacing high heat gas heat
models in the 27.5 ton to 35 ton cabinet.
When replacing all other Trane units, it is
recommended that the installer use the roof curb
alignment kit, 1RB0401 . This kit will aid in properly
aligning the new unit with the existing roof curb.
Compressors
The scroll compressor used in this product is
specifically designed to operate with R-410A
refrigerant and cannot be interchanged.
CAUTION
This system uses R-410A refrigerant that operates at
higher pressures than R-22. No other refrigerant may
be used in this system.
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 the
necessary precautions to avoid exposure of the oil
to the atmosphere.
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
POE compressor lubricants are known to cause long
term damage to some synthetic roofing materials.
CAUTION
Exposure, even if immediately cleaned up, may cause
embrittlement (leading to cracking) to occur in one
year or more. When you perform any service that
may risk exposure of compressor oil to the roof, take
precautions to protect the roofing.
Procedures that risk oil leakage include, but are not
limited to the following:
• Compressor replacement
• Repairing refrigerant leaks
• Replacing refrigerant components such as the
filter drier, pressure switch, metering device
or coil
Units are shipped with compressor mountings that
are factory-adjusted and ready for operation.
Installation Manual: YORK
®
Sun™ Select YV28 to YV50
29
Johnson Controls Ducted Systems