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General, Description, Construction – York Y33 User Manual

Page 89: Base, Casing, Supply air system, Supply air fan, Optional, Bearings and drives, General description construction

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246653-YTG-E-0108

Johnson Controls Unitary Products

89

GUIDE SPECIFICATIONS - YORK
MILLENNIUM 25, 30, & 40 TON UNITS

GENERAL

Units shall be manufactured by Johnson Controls Unitary
Products in an ISO 9001 certified facility. Introducing the
YORK Millennium 25, 30, & 40 ton rooftop line - units
designed to provide peak performance and value both today
and for years to come. Millennium units are manufactured at
an ISO 9001 registered facility, and each rooftop is com-
pletely computer-run tested prior to shipment. The Millennium
is designed to be flexible enough to meet your needs today
and in the future. The true value of York's Millennium is that it
can be designed to fit any need, from cooling only, constant
volume applications to variable air volume systems with vari-
able frequency drive.

DESCRIPTION

Supply York Millennium packaged rooftop system in accor-
dance with the capacities in the plans. Units shall be rated by
the manufacturer at a minimum (30/40 Ton units: 9.5 EER /
25 Ton units: 10 EER) according to ARI 360. Units shall be
shipped in a single package, fully charged with R-22 refriger-
ant. The manufacturing facility shall be registered under ISO
9001 Quality Standards for Manufacturing. Units shall carry
both ETL and CSA safety approval ratings. Tags and decals
to aid in the service or indicate caution areas shall be pro-
vided. Installation and maintenance manuals shall be sup-
plied with each unit. Units shall be capable of providing
mechanical cooling down to 40°F (0°F with low ambient kit).
Unit shall be capable of starting and running at 125°F. Unit
electric and gas connections shall be either through the curb
or the side of the unit.

CONSTRUCTION

Base

The base rail shall be constructed of 12 gauge galvanized
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, pro-
viding a positive, weather tight seal between the unit and the
curb.

Casing

The unit cabinet shall be double wall construction 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. Sheet metal shall be cleaned in an alkaline
and zinc phosphate bath, and the exterior surfaces shall be
coated with a 1.5 mil powder paint, capable of withstanding
1000 salt spray hours in accordance with ASTM B-117. The
unit shall be insulated with 1-1/2", 1 pound density fiberglass
insulation between the two sheet metal skins. Insulation shall

meet NFPA-90A regulations for smoke and flame spread rat-
ings. The cabinet corner post and the intermediate side sup-
ports shall be 16 gauge steel. All access doors shall be 18
gauge on the exterior surfaces, and 20 gauge on the interior.
Floor shall be 18 gauge, and 24 gauge. All serviceable sec-
tions shall have hinged access doors with latches on both
sides of the unit. All access doors shall be constructed of 20
gauge steel on the outside, with 24 gauge on the inside. Each
door shall seal against a rubber gasket to prevent 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
sidewalls 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 rubber gasketing. Each fastened seam shall be
further protected by a sheet metal channel covering the full
length of the gasket surface, making a completely water tight
seal.

SUPPLY AIR SYSTEM

SUPPLY AIR FAN

Fans shall be centrifugal type - Class I or Class II, 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. 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
(optional 1”, 2" deflection springs or rubber isolators). The fan
discharge shall be connected to the cabinet through a rein-
forced neoprene flexible connection to eliminate vibration
transmission from the fan to the unit casing. Fans shall be
double-width, double-inlet with forward curved blades.

OPTIONAL

On variable air volume units without variable frequency
drives, fans shall be provided with heavy gauge, corrosion
resistant blades, with zinc-plated steel inter-locking operating
mechanism. Both inlet vanes must operate from a single
shaft and be synchronized for precise control.

Units equipped with variable frequency drive on supply fan
must be controlled by a duct static transducer providing a 2-
10 VDC signal to the drive. Supply fan variable frequency
drives shall have factory option of being equipped with a
manual drive bypass.

BEARINGS AND DRIVES

Bearings shall be self-aligning pillow-block re-greasable ball
bearings with an average life expectancy of 200,000 hours.
Grease fittings shall be accessible through access doors. Fan
motors shall be NEMA designed, Standard efficiency (option,
Hi-efficiency) 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

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