2.9.18.6
Equipment Speed Response Switch
Actuates a control signal when preset abnormal equipment operating
conditions are encountered. Switch shall be adjustable so that it may be
used as an underspeed switch, overspeed switch, or zero speed switch.
Switch shall consist of input shaft from which the equipment speed is
measured and compared to a preset point. Enclosure shall be cast iron or
suitably protected cast aluminum. Mount speed response switches as
indicated. Type of switch adjustment, type and number of contacts, and
voltages shall be as indicated on control diagrams.
2.9.18.7
Presence Indicators and Response Switches
Provide at hoppers and conveyor discharges located and protected according
to manufacturer's recommendations to ensure safe and reliable operation.
Mount presence indicators in such a manner that they will not be damaged by
occasional large lumps or falsely operated by stray lumps or collected
amounts of coal.
2.9.19
Control Panel and Controls
Provide a semi-automatic control system for coal handling system as
indicated.
2.9.19.1
Control Panel
NEMA 12 construction, centrally located in main plant control room. Panel
front shall include a system graphic display as indicated. Display shall
be approximately to scale and painted with an industrial acrylic enamel.
Outline each item with 3 mm 1/8 inch wide black lines. Lettering shall be
on engraved plastic screwed to front of panel, with white letters on a
black background. Provide controls for operation on [_____] volt, [_____]
phase, 60 Hz ac. Panel shall be complete with an annunciator and
interlocks, relays, switches, running and safety lights, and auxiliary
parts necessary to safely control and operate the system. Items located in
door shall be dust-tight and oil tight with push-to-test transformer type
indicating lights. Control relays shall be 10 amp, 600 volt class with
convertible contacts. Provide and mark terminals for connections with the
exception of the neutral. Panel shall contain [_____] percent spare
terminals. Wiring shall be No. 14 AWG type THHN stranded. Neutral wire
shall be white. Color code and label wiring of 120 volts or less. Provide
plastic wire duct of sufficient size to provide [_____] percent cross
sectional spare. Wiring shall be in accordance with requirements of NFPA 70.
a.
Panel Devices: Control panel shall include the following
indicating lights (color in parenthesis):
(1)
Power - ON
(red)
(2) System Run (3 required)
Rail unloading hopper to boiler plant
(green)
Rail unloading hopper to storage yard
(green)
Reclaim hopper to boiler plant
(green)
(3)
Rail unloading hopper surfactant sprays - ON
(green)
(4)
Reclaim hopper surfactant sprays - ON
(green)
(5)
Belt feeders - ON
(green)
SECTION 15501N
Page 90
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