a. If 800 Series dc mill type motors are specified,
select AISE Std No. 1.
b. Select dc motor type (squirrel cage, wound
rotor) for the appropriate control system.
c. Select dc series wound motors for dc constant
potential control.
d. Select dc shunt wound for dc variable voltage
control.
e. Select ac motor (squirrel cage, wound rotor) for
the appropriate control system.
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2.4.4.1
General Requirements
Motors shall be designed specifically for crane and hoist duty. Drain
holes shall be provided at low points near each end. Inspection and
service covers shall be provided with gaskets. Hardware shall be
corrosion-resistant. Motors shall conform to the requirements of NFPA 70, [
NEMA MG 1] and UL 1004. Motor heaters shall be energized when mainline
contactor is de-energized, and water heaters shall be de-energized when
mainline contactor is de-energized. Motors 15 kW 20 HP and larger shall be
provided with a suitable heater to prevent condensation during long periods
of inactivity. One thermal sensitive device embedded in hoist motor
windings shall be provided. Device and associated circuitry shall serve as
an alarm activating an amber signal or pilot light visible to control
stations when motor temperatures become excessive. Set point shall be set
below the Class B insulation temperature limit. Thermal-sensitive device
and associated circuits shall be self-restoring (automatic reset).
Two-speed, two-winding motors with a solid-state control will not be
allowed for creep-speed use.
2.4.4.2
Main [and Auxiliary Hoist] Motor
Hoist motor shall be [dc crane type] [dc industrial type] [800 Series dc
mill type] [[single-speed; single-winding] [two-speed; two-winding]] [NEMA
design D squirrel cage ac type] [wound-rotor type ac type] [ac squirrel
cage type for use in ac adjustable frequency control systems] [dc series
wound type] [dc shunt-wound type].
2.4.4.3
[Bridge] [Gantry] and Trolley Drive Motors
[Bridge] [Gantry] and trolley drive motors shall be [ac crane type] [dc
industrial type] [800 Series dc mill type] [[single-speed; single-winding]
[two-speed; two-winding]] [NEMA design B squirrel cage ac type rated]
[wound rotor ac induction type] [ac type designed for ac adjustable
frequency operation] [dc series wound type] [dc shunt-wound type].
2.4.4.4
Motor Enclosures
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NOTE: Applicable to 1 or 2 speed ac magnetic
control of ac squirrel cage motor. If it is not
desirable to have the motor immediately reverse
direction, include sentence on plugging to allow the
SECTION 14630A
Page 31
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