YORK INTERNATIONAL
72
Guide Specifications
(continued)
Fan motors shall be NEMA designed, Standard effi-
ciency ball bearing type with electrical characteristics
and horsepower as specified. Motors shall be 1750
RPM, open drip proof type. The motor shall be located
within the unit on an adjustable, heavy steel base.
All fan motor drives shall be selected for a minimum
service factor of 1.2 and have fixed pitched sheaves.
AIR FILTERING SYSTEM
All filter holding frames shall be of heavy-duty construc-
tion designed for industrial applications. All filters shall
be accessible from either side via access doors on both
sides of the filter section.
All filter media shall be Class II listed under U.L. Stan-
dard 900. Filter efficiencies shall be rated in accordance
with ASHRAE Standard 52.
Two-inch throwaway filters in an angled filter rack shall
be standard. On units with rigid filters, two-inch prefilters
shall be installed upstream of the rigid filters.
AIR INLET SYSTEM
A factory installed outside air rain hood permanently
attached to the cabinet to prevent windblown precipita-
tion from entering the unit shall cover inlet openings.
The rain hoods on the sides of the unit shall be rotated
into the cabinet and secured for shipment so that upon
installation they need only be rotated upwards and
screwed into place. The outside air hood shall contain
a removable and cleanable filter.
All damper assemblies shall be of low leak design.
Damper blades shall be fabricated from a minimum of
16-gauge galvanized steel.
REFRIGERATION SYSTEM
Units shall have four compressors (six for YPAL070 -
095) for maximum load-matching capability. Each refrig-
erant circuit shall be controlled by two thermal expan-
sion valves for maximum control at low load conditions.
Evaporator Coils
Evaporator coils shall be direct expansion. Coil tubes
shall be 1/2" OD copper, with internally enhanced tubes.
Fins shall be enhanced aluminum mechanically ex-
panded to bond with the copper tubes. Coil casing shall
be fabricated from heavy gauge galvanized steel.
A stainless steel double-sloped drain pan shall be pro-
vided under the entire width of the evaporator coil, in-
cluding all return bends. The main drain pan shall be
sloped a total of 1/4" per foot towards the drainage point
according to ASHRAE 62 guidelines. Main drain pan
shall be accessible and cleanable in the field. The con-
densate drain opening shall be flush with the bottom of
the drain pan to allow complete drainage.
Compressors
Compressors shall be hermetic, scroll-type, including
tip seals to provide efficient axial sealing while prevent-
ing scroll tip to base contact, controlled orbit design for
radial sealing to incorporate minimum flank-to-flank
contact for long service life, refrigerant cooled motors,
large suction side free volume and oil sump to provide
liquid handling capability, annular discharge check valve
and reverse vent assembly to provide low pressure
drop, silent shutdown and reverse rotation protection,
initial oil charge, oil level sight glass, vibration isolator
mounts for compressors, and brazed-type connections
for fully hermetic refrigerant circuits.
Condenser Coils
Condenser coils shall have 3/8" seamless copper tubes,
arranged in staggered rows, mechanically expanded into
aluminum fins. Coils shall be protected from hail dam-
age with a “V” configuration, with individual flat coils ro-
tated from the vertical plane for each condensing circuit.
Condenser Fans and Motors
Condenser fans shall be direct drive, propeller type,
discharging vertically. Condenser fan motors shall be
3-phase, totally enclosed air over (TEAO). Thermal
overload protection shall be provided for each con-
denser fan motor.
Refrigerant Piping
All interconnecting piping between refrigeration com-
ponents shall be copper tubing with brazed joints.
Each refrigerant circuit shall be equipped with liquid line
filter drier, and moisture indicating sight glass. Each
circuit shall also have both high and low pressure
switches and include access fittings for replacement of
the pressure switches without removing charge.
Polyurethane sleeves shall protect all small diameter
distributor tubing to the evaporator coil to prevent the
tubes from copper-to-copper contact during shipment
or operation.
