2.3
MECHANICAL
2.3.1
Threaded Fasteners
Fasten base-mounted and flange-mounted components and all mechanical
connections subjected to calculable loads with ASTM A 325M ASTM A 325 plain
uncoated bolts with appropriate ASTM A 194/A 194M or ASTM A 563M ASTM A 563
plain nuts; and ASTM F 436M ASTM F 436 plain, through hardened, flat,
circular washers. Alternatively, provide SAE J429, Grade 5, screws with
properly torqued matched SAE J995, Grade 5 nuts. Match bolt and nut
threads. Oversize tapping is not permitted. Bolt and nut threads shall
conform to ASME B18.2.2 and ASME B1.1. Bolts and screws may be installed
into tapped holes only in heat treated steel with a minimum hardness of 195
BHN.
2.3.2
Antifriction Bearings
Provide antifriction type bearings, except where bushings are specifically
permitted or required. Provide grease lubricated bearings with means for
relubrication through easily accessible lubrication fittings or provide
permanently lubricated and sealed bearings.
2.3.3
Bushings
Provide manufacturer's standard bronze alloy bushings and thrust washers.
Provide means for relubrication of grease lubricated bushings through
easily accessible lubrication fittings or provide oil impregnated type
bushings.
2.4
ELECTRICAL
The design, selection, rating, and installation of the electrical portions
of the crane and its accessories shall conform to the requirements of NEMA
ICS 3, ASME HST-4, and NFPA 70, and other requirements specified herein.
The crane manufacturer shall furnish and install all electrical equipment
on the crane, including motors, electrically released brakes, switches,
controllers, panels, operating station, wiring system, cables, and
bridge-to-trolley electrification[, and the runway electrification].
2.4.1
Wiring System
Provide the wiring system, with all of its associated hardware, fittings,
and devices, in accordance with NFPA 70. Provide type THHN or TFFN
conductors in raceways and type [MTW or TFFN ][double rated MTW/THHN ]
conductors on control panels. Provide type MTW or TFFN insulation for
conductors connected to, or routed above, resistors.
Provide ferrous rigid metal conduit raceways suitable for wet locations;
where flexible connections are necessary, provide liquidtight flexible
metal conduit. Provide an equipment grounding conductor, sized in
accordance with Section 250-95 of NFPA 70, with all ungrounded conductors.
Provide No. 4 AWG (25 mm2) minimum for leads from the runway contact
conductors. Number or tag wiring at connection points.
2.4.2
Motors
NEMA MG 1. Provide AC squirrel cage induction type motors for the bridge
and trolley drives. Provide two speed, AC squirrel cage induction type
SECTION 14637N
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