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
