motor for the hoist. Motor insulation shall be Class F. Provide totally
enclosed non-ventilated (TENV) motor enclosures, bridge drive motor may be
totally enclosed fan-cooled (TEFC). Hoist motor speed shall not exceed
1800 RPM..
2.4.3
Pendant Pushbutton Station
Crane bridge, hoist and trolley motions shall be controlled by crane
operator from a pendant pushbutton station.
Locate station [1.2 m] [4
feet] [_____] above the finished floor.
Suspend pendent pushbutton station from festooning type electrification
utilizing flat cables suspended from carriers riding in an enclosed steel
track along the bridge. Suspend station by a small cord strain lead 3 mm
1/8 inch (minimum), 7 by 19 construction, made from corrosion resistant
steel, and conforming to FS RR-W-410. Provide Type SO cable for pendent
cable with a minimum of 20 percent of its conductors reserved as spares at
the time of crane acceptance by the Contracting Officer.
Arrange pushbuttons in accordance with ASME
B30.11 recommendations, except
as supplemented or modified herein. On the
pushbutton station, provide a
pilot light to indicate that the pendant is
energized . Provide a pilot
light on the crane mounted electrical panel
to indicate that power is
available to the crane .
2.4.4
2.4.4
AC Controls
**************************************************************************
NOTE: Select one of the following options. The
first option provides magnetic controls for the
bridge, trolley, and hoist. The second option
provides electronic controls for the bridge and
trolley and magnetic controls for the hoist.
**************************************************************************
[2.4.4.1
Magnetic Two-speed Controls
Provide two-speed magnetic controls for the bridge drive, trolley drive,
and hoist motors. Ensure that an energized drive motor initially rotates
only in the direction selected by the operator by depressing the
corresponding pushbutton; i.e., is not overhauled. Feed control circuits
from a single phase, air cooled, double wound transformer with a grounded
metal screen between the primary and secondary windings of the transformer.
a.
Bridge and Trolley Control: Provide bridge drive and trolley
drive motor control systems with a solid state soft start,
adjustable for both time and torque.
Ensure smooth acceleration
and deceleration.
b.
Hoist Control: Feed control circuit from a single phase, air
cooled, double wound transformer with a grounded metal screen
between the primary and secondary windings of the transformer.
Hoist shall be equiped with a mechanical load brake.
][2.4.4.2
Electronic and Magnetic Controls
Provide provide two-step adjustable frequency controls for the bridge and
trolley drive motors and two-speed magnetic controls for the hoist motor.
SECTION 14637N
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