relays, contactors, circuit breakers, control transformers, and devices for
complete control of each hopper heater system, in the control room.
Enclosed in a NEMA ICS 6 [Type 12] [Type 4] [floor] [wall] mounted
enclosure and include the following:
a.
One main circuit breaker.
b.
One circuit breaker and contactor alarm relay with two normally
open contacts for each hopper zone. The contactor shall have a
120 V operating coil.
c.
"ONLINE," "OFF," "AUTO" selector switch for each hopper.
d.
120 V "HIGH LEVEL" red light with integral transformer for each
hopper.
e.
120 V "ON" green light with integral transformers for each hopper.
f.
120 V "LO TEMP" white light with integral transformer for each
hopper.
g.
Device and enclosure nameplates screwed or riveted to panel.
h.
Auxiliary relays and equipment required for operation of the
heating and alarm systems.
i.
Fused control transformer having a 120 VAC secondary.
2.9
ACCESS PROVISIONS
2.9.1
Access Requirements
Provide access stairs, walkways, and platforms from boiler to baghouse.
Baghouse access shall include interior and exterior access, including
access to manifolds, bags, tube sheet, weather enclosure, hoppers, valves,
conveyors, expansion joints, dampers, gas sampling ports, poke holes, and
equipment requiring routine maintenance, repair, or replacement. Access
provisions shall comply with OSHA regulations. Interconnect walkways and
platforms on each side of the baghouse or each side of equipment, at the
same elevation, by walkways. Connect walkways, including roof, by stairs.
Provide caged ladders at each level for secondary egress. Provide
allowance for installing piping, conduit, electrical outlets, and lighting
fixtures. Provide 7 feet headroom clearance above walkways, platforms, and
stairs. Provide manholes, inspection doors, and access doors with internal
and external access walkways, lights, and platforms, at areas requiring
access for operation and maintenance. Operation and maintenance access
requirements are listed, by Class, below:
2.9.1.1
Class 1
Regularly attended areas including: lubricated equipment, bearings,
instruments, valve operators, damper operators, damper linkages, damper
drives, test ports, instrument connections, and equipment requiring daily
inspection, maintenance, and operation. Provide platforms accessible by
stairs. Do not use a ladder or ship ladders.
2.9.1.2
Class 2
Periodic maintenance access areas including expansion joints, ductwork
SECTION 15863N
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