OO-A-373D
3.8 Construction. Conditions which can be hazardous to personnel or deleterious to equipment shall not be permitted.
3.8.1 Component parts.
3.8.1.1 Enclosure. The enclosure shall be constructed of reinforced sheet metal suitable for installation in interior or exterior locations as required by UL 1995. Unless otherwise specified (see 6.2), interior located units shall be suitable for exposed installation in an office space. The enclosure design shall include mechanical features which shall be suitable for floor, ceiling, roof mounting, or other installation methods as specified (see 6.2).
3.8.1.2 Plenums, grilles, and duct connections. Plenums, grilles (style A), and duct connections (style B) shall be furnished to harmonize with the cabinet. Outlet grilles, when required, shall be constructed to permit adjustable directional air flow in both horizontal and vertical planes.
3.8.1.3 Provisions for ventilation air. When specified (see 6.2), knock-out plates or similar provisions for introducing outside air to the return air side of the unit shall be provided.
3.8.1.4 Roof mounting. When specified (see 6.2), roof mounted units shall be provided with matching roof mounting frames for the style unit specified herein. Units less than 65,000 Btu/hr (19 050 W) may be mounted on matching roof frames or on steel sleepers on the roof with ducts extended through the roof.
3.8.1.5 Insulation. Units to be located within conditioned spaces (see 3.4.1.1 and 3.4.1.2) shall have the interior of the enclosure insulated. All other units shall have all conditioned air sections insulated. Insulation shall be glass fiber, or other suitable material acceptable to UL 1995, properly secured to the inside of the metal housing. Insulation shall be of suitable thickness to meet the requirements of 3.11.9.
3.8.1.6 Duct adapters. Duct openings to the outside shall be provided with screens not more than 0.5-inch (12.7 millimetre (mm)) mesh or equipment openings on the weather side. Provisions shall be made for draining or excluding rain water to prevent its entrance into the unit or room.
3.8.2 Compressor. Unless otherwise specified (see 6.2), compressor shall be hermetically or semi-hermetically sealed (see 6.9). The compressor shall be mounted with means for vibration isolation. All moving compressor parts shall be oiled automatically and provisions shall be made to return oil from suction lines to housing or crankcase. As many as four compressors may be used but not more than two may be parallel. For units over 240,000 Btu/hr (70 337 W) with multiple compressors, there shall be a time delay or other means to sequence the starting of the compressors operating. Lead-lag sequencing shall not be used on stacked evaporator circuits with units less than 240,000 Btu/hr (70 337 W). Provisions shall be made to protect the compressor against damage caused by liquid entering the suction side of the compressor.
7
For Parts Inquires submit RFQ to Parts Hangar, Inc.
© Copyright 2015 Integrated Publishing, Inc.
A Service Disabled Veteran Owned Small Business