Specifications

December 2013
REQUEST FOR PROPOSALS FOR
PURCHASE AND DELIVERY OF HEAVY-DUTY BUSES
RFP SRTA-2014-01
TECHNICAL SPECIFICATIONS
PAGE-68
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(a) High pressure cutout switch.
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(b) Low pressure cutout switch.
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(c) Ambient sensing switch 45 + 5 F cutout 55 + 5 F cut-in.
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(d) These switches will interrupt the compressor energizing circuit. Both the high and
low pressure switches will energize a trouble light at the driver's console.
(e) High pressure relief valve.
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(f) Evaporator coil freeze protection - The system will be equipped with an evaporator
pressure regulator or Anti-Freeze thermostat to prevent condensate freezing on
the evaporator coil.
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22.15 Compressor
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a. The air conditioning system shall be provided with a 4 cylinder, in-line V, 25.9 CID,
reciprocating compressor. The compressor shall be capable of cycling on/off at any
operating speed - no unloaders are to be used. It shall have aluminum body, heads and
sump; free floating ring type suction valves, free floating ring type discharge valves with
spring loaded cage to accept liquid slugging; two ball bearing mains, one on the front and
one on the rear of the crankshaft for support; steel connecting rods with replaceable
insert bearings on both ends; vanvsil alloy ringless pistons, replaceable cast iron cylinder
sleeves; gerotor oil pump; 8.9 point oil sump. Synthetic 150 SUS oil shall be used. High
and low refrigerant pressure cutout switches shall be mounted on the compressor.
Suction and discharge service valves shall be made of brass, with steel stems.
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b. The compressor clutch shall be an electromagnetic design which utilizes a double row,
open type ball bearing. The inner race of the ball bearing shall mount on the hub of the
front compressor seal plate and shall be held in place by a locking nut. The outer race of
the bearing shall be pressed into the pulley cavity and held in place by a snap ring.
External Teflon grease seals mounted in the clutch pulley shall hold a large reserve of
Exxon Unirex N2 high temperature grease, or approved equal, on both sides of the
clutch bearing for maximum lubrication. The front seal shall have a grease zerk to
conveniently enable bearing relubrication without disassembly of the clutch disc.
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c. The air gap between the clutch disc and mating pulley plate surface shall be adjustable.
The clutch pulley plate shall be thick enough to allow for removal of .030 inch of material
during resurfacing on a lathe during overhaul.
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23. BIKE RACKS
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a The Proposer shall install front mounted bicycle racks to each coach prior to delivery.
The rack shall be a Sportworks Model 100156, or approved equal, including all
necessary brackets, mounting hardware and bike retention accessories. A sensor
manufactured by Sportworks which the warns Operator the rack is deployed shall be
provided. The warning indicator shall be located on the dash in a location approved by
the SRTA.
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b. The Proposer shall advise, during the approved equal period, if the bike rack installation
will impact the front headlights of the coach design to be offered and what, if any,
modifications are necessary to accommodate the specified racks. The mounted bike rack
shall not interfere with attaching towing equipment, accessing towing connectors or obstruct
the driver’s field of vision.