FORM 100.50-EG3 (802)
71
YORK INTERNATIONAL
Guide Specifications
GENERAL
Units shall be designed for outdoor rooftop installation
on a roof curb (optional). Units shall be capable of pro-
viding mechanical cooling down to 7.2°C (-17.7°C with
a low ambient kit). Unit shall be capable of starting and
running at 48.8°C. Unit electric and gas connections
shall be either through the curb or the side of the unit.
QUALITY ASSURANCE
Units shall be rated according to ARI 360 and conform
to ASHRAE 90.1 energy efficiency requirements. Units
shall be shipped in a single package, fully charged with
HFC-407C (HCFC-22 optional) refrigerant. The manu-
facturing facility shall be registered under ISO 9001
Quality Standards for Manufacturing. All units shall be
completely factory wired and assembled, and undergo
a complete and automated factory run test. The factory
run test shall confirm proper operation of all functional
components on the unit, configure the unit controller
per the project and test the unit controller. Units shall
be E.T.L. listed and be tested according to U.L. 1995.
Warranty
Manufacturer shall Warrant all equipment and material
of its manufacture against defects in workmanship and
material for a period of one year from date of initial
start-up or eighteen (18) months from date of shipment,
whichever occurs first.
SHIPPING PREPARATION AND UNIT CLEANLINESS
All units shall be shipped from the factory shrink-wrap
in plastic to maintain a clean unit interior for maximum
indoor air quality and to protect the exterior finish of the
unit during transit. Tags and decals to aid in the service
or indicate caution areas shall be provided. Installation,
operation and maintenance manuals shall be supplied
with each unit.
CONSTRUCTION
Base
The base rail shall be constructed of 12-gauge galva-
nized steel, extending the full perimeter of the unit. All
components shall be supported from the base, and the
base shall include integral lifting lugs. The unit base
rail shall overhang the roof curb for water runoff and
shall have a fabricated recess with a continuous flat
surface to seat on the roof curb gasket, providing a
positive, weather tight seal between the unit and the
curb.
Casing
The unit cabinet shall be one-inch double-wall construc-
tion of all panels, doors, floor, roof and walls to provide
both maximum resistance to bacterial growth in the air
stream and superior structural integrity. All sheet metal
shall be G90 mill galvanized sheet metal, formed and
reinforced to provide a rigid assembly. Cabinet shall be
coated with baked on powder paint which, when sub-
ject to ASTM B117, 500 hour, 5% salt spray test. The
unit shall be insulated with 1-1/2 pound fiberglass insu-
lation between the two sheet metal skins. Insulation shall
meet NFPA-90A regulations for smoke and flame
spread ratings. Single-wall units, or foil-faced insula-
tion in the air stream shall be not acceptable.
The cabinet corner post and the intermediate side sup-
ports shall be a minimum of 16-gauge steel. All access
doors shall be a minimum of 18-gauge on the exterior
surfaces, and 20-gauge on the interior. Interior floor
panels shall be 18-gauge. All serviceable sections shall
have hinged access doors with latches on both sides
of the unit. Each door shall seal against gaskets to pre-
vent air and water leakage.
The roof shall be double wall, with 18-gauge on the
external surface and 24-gauge on the interior. The roof
shall be formed with a 45 degree “drip lip” overhanging
the side walls to prevent precipitation drainage from
streaming down the side of the unit. Roof sections shall
be connected together via integral channels fastened
with screws and sealed with gasketing. Each fastened
seam shall be further protected by a sheet metal chan-
nel covering the full length of the gasket surface, mak-
ing a completely water tight seal.
SUPPLY AIR FAN
Fan shall be centrifugal type, statically and dynamically
balanced in the factory. Fan wheels shall be designed
for continuous operation at the maximum rate of fan
speed and motor HP. Fans shall be double-width,
double-inlet with forward curved blades.
The fan and motor assembly shall be mounted on a
common base to allow consistent belt tension with no
relative motion between the fan and motor shafts. The
entire assembly shall be isolated from the unit base
with 1" deflection springs. The fan discharge shall be
connected to the cabinet through a reinforced neoprene
flexible connection to eliminate vibration transmission
from the fan to the unit casing.
Bearings shall be self-aligning pillow-block re-greasable
ball bearings with an average life expectancy L50 of
200,000 hours. Grease fittings shall be accessible
through access doors.
