Specifications

December 2013
REQUEST FOR PROPOSALS FOR
PURCHASE AND DELIVERY OF HEAVY-DUTY BUSES
RFP SRTA-2014-01
TECHNICAL SPECIFICATIONS
PAGE-67
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22.9 Electrical Wiring and Terminals
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All unit wiring shall be UL758, Style 3173/3196 having copper strands with tinned ally coating
rated for up to 600 volts. The insulation shall be cross-linked polyethylene, rated for 125
o
C and
shall be white in color with hot stamp number coding the entire length at a maximum spacing of
1-3 inches. All terminals shall be "forklok" or ring type with vinyl insulation. All terminals shall be
machine crimped. Hand crimping is not acceptable. All terminations exposed to ambient shall be
coated with glycol for corrosion protection.
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22.10 Receiver Tank, Dry Eye, Filter/Dehydrator
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The unit shall be equipped with a refrigerant receiver tank installed vertically to ensure a steady
liquid feed to the expansion valve. The receiver tank shall meet all ASTM requirements and have
two (2) sight glasses for checking refrigerant level. The top sight glass shall have a floating
plastic ball to indicate proper refrigerant level. A refrigerant dry eye shall be provided in the liquid
line, or in the lower sight glass of the receiver tank, to indicate the presence of moisture in the
refrigerant system. The unit shall have a disposable liquid line filter/dehydrator.
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22.11 Refrigerant Hoses, Copper Tubing, Fittings
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a. Suction and discharge hoses shall be provided to connect the air conditioning unit to the
compressor. The hoses shall have reusable swivel fittings, Teflon liner, stainless steel
interior support coil, stainless steel exterior braid, and asbestos exterior sleeve for
abrasion protection. Length of such hoses shall be kept to a minimum to minimize
effusion of refrigerant or permeation of moisture.
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b. All copper tubing provided shall be refrigeration grade, Series 122 seamless type
meeting ASTM specifications. All solder joints shall be silver soldered. All flux and scale
shall be cleaned from solder joints, prior to soldering, and all tubing exposed to ambient
shall be sprayed with fungus proof varnish.
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c. All JIC and SAE swivel fittings of 3/4" flare size and larger shall include "O" rings for
added sealing protection. "O" ring material must be compatible with refrigerant.
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22.12 Expansion Valve
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The expansion valve shall be externally equalized. It shall have a replaceable power head and
cage assembly and be equipped with a 100 mesh screen at the inlet to prevent contaminants
from plugging the seat. The superheat shall be factory set, requiring no field adjustment. The
expansion valve bulb shall be clamped to the suction line in the evaporator compartment and
insulated from effects of surrounding air temperature. The expansion valve body shall be properly
secured and mounted in the return air area for ease of access.
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22.13 System Performance
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The T Series system shall control the interior coach temperature to meet all White Book
temperature control performance requirements defined in Chapter 3.7, INTERIOR CLIMATE
CONTROL, of the Department of Transportation URBAN MASS TRANSPORTATION
ADMINISTRATION, BASELINE ADVANCE DESIGN TRANSIT COACH SPECIFICATIONS.
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22.14 System Protective Controls
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The air conditioning system will be equipped with the following protective control: