and torque output to move the door in either direction from any position.
Motor shall produce a door travel speed of not less than 200 mm two-thirds
foot or more than 300 mm one foot per second without exceeding the rated
capacity. Motors shall operate on current of the characteristics indicated
at not more than 377 rad/s 3600 rpm. [Single-phase motors shall not have
commutation or more than one starting contact.] [Motor enclosures shall be
drip-proof type or NEMA totally enclosed non-ventilated (TENV) type.]
Install motors in approved locations.
2.4.2
Controls
Each door motor shall have an enclosed, across-the-line type, magnetic
reversing contactor, thermal overload and undervoltage protection,
solenoid-operated brake, limit switches, and control switches. Locate
control switches at least 1500 mm 5 feet above the floor so the operator
will have complete visibility of the door at all times. Control equipment
shall conform to NEMA ICS 1 and NEMA ICS 2. Control enclosures shall be
NEMA ICS 6, Type 12 or Type 4, except that contactor enclosures may be Type
1. Each control switch station shall be of the three-button type; buttons
shall be marked "OPEN," "CLOSE," and "STOP." The "OPEN" and "STOP" buttons
shall require only momentary pressure to operate. The "CLOSE" button shall
require constant pressure to maintain the closing motion of the door. If
the door is in motion and the "STOP" button is pressed or the "CLOSE"
button released, the door shall stop instantly and remain in the stop
position; from the stop position, the door may be operated in either
direction by the "OPEN" or "CLOSE" buttons. Pushbuttons shall be
full-guarded to prevent accidental operation. Provide limit switches to
automatically stop doors at the fully open and closed positions. Limit
switch positions shall be readily adjustable.
2.4.3
Safety Device
Provide a safety device on the bottom edge of electrically operated doors.
The device shall immediately stop and reverse the door in its closing
travel upon contact with an obstruction in the door opening or upon failure
of the device or any component of the control system and cause the door to
return to the full open position. The door-closing circuit shall be
automatically locked out and the door shall be operable manually until the
failure or damage has been corrected. Do not use the safety device as a
limit switch.
2.4.4
NEMA ST 20. Provide transformers in power circuits as necessary to reduce
the voltage on the control circuits to 120 volts or less.
2.4.5
Electrical Components
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NOTE: Ensure that labor and materials for
connecting motors and controls are specified in the
electrical section, e.g., "Vertical Lift Metal
Doors." Mount controls, including Type SO cable and
takeup reels furnished by the door manufacturer, and
provide necessary conduit, conductors, and devices
in accordance with door manufacturer's wiring
diagrams."
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SECTION 08370
Page 8
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