field contacts which close on alarm condition. Do not use contacts which
open on alarm condition. Provide an auxiliary isolated contact for each
station. The auxiliary contact action shall follow that of the field
contact. Provide cover-mounted annunciator, test, audible silence, flasher
reset, lamp reset, and acknowledge pushbuttons on a NEMA ICS 6, Type 12
enclosure. Mount and wire the following devices inside the enclosure:
a.
Annunciator audible device.
b.
Fuse and fuse holder for annunciator power supply.
c.
Fuse and fuse holder for the audible device.
d.
Terminal blocks for connections to all external circuits.
2.3.12
Electrical Service Outlets
Provide a 20 amp, 110 VAC duplex ground fault NEMA 5 20R terminal duplex
interrupter receptacle within 2.44 meters 8 feet of access doors except
doors in the hot-roof and gas distribution plates. The receptacles on each
precipitor level shall be on a separate circuit. Ground fault interrupters
shall test and reset at the receptacle. Wire receptacles to provide
individual receptacle protection such that no other receptacles are
interrupted by an individual receptacle trip. The receptacle shall
interrupt at 5 plus or minus 1 milliamp ground fault current. Provide
specification grade or better receptacles and protect by weather tight
covers. Provide a CS 6369 (Alpha Configuration) 50 amp, 3 pole, 4 wire ,
120/250 VAC twist type receptacle in a FS box with a weatherproof cover
(Hubbell SR-50 or approved equal - item may be provided as an integral
assembly or as individual components) inside each weather enclosure on
separate circuits. Provide a weatherproof 100 amp, 3 pole, 4 wire, 120/250
VAC, pin ad sleeve receptacle conforming to IEC 309 within 15 meters 50 feet
of each stack base and each precipitator base. Provide each of the 50 amp
receptacles with an individual 50 amp, 208 VAC service. Provide each of
the 100 amp receptacles with an individual 100 amp 208 VAC service.
2.4
HOUSING
Construct the precipitator housing, including inlet and outlet nozzles, of
minimum 6 mm 1/4 inch thick steel plate and attach to appropriate
structural steel supporting members. Plumb the housing within 10 mm 3/8
inch measured at top, bottom, and tie points, side to side, and front to
rear. The top of the precipitator support shall be flat within 1.50 mm
1/16 inch for area of support foot and at elevation within 3.18 mm 1/8 inch.
Make provisions, including expansion joints if required, to allow for any
expansion, differential expansion, and contraction that may occur. Design
the expansion provisions to prevent escape of gas or inflow of ambient air.
Provide a minimum of 1.50 meters 5 feet of vertical clearance inside the
housing above the discharge electrodes and collecting surface frames to
afford access for inspection and maintenance. Locate walkways internal to
the housing between electrical fields, at the inlet to the first field, at
the outlet to the last field, and as otherwise required to provide access
to equipment located within the housing which may require inspection or
maintenance. Provide access to internal walkways by two access openings
located on opposite sides of the precipitator for each internal walkway.
Access openings shall align directly with internal walkways and shall be
unobstructed. The walkways shall provide a minimum passageway clearance of
762 mm 30 inches. Provide the housing with insulated, hinged, quick
opening, access, inspection, and cleanout doors with gastight seals as
SECTION 15862N
Page 33
Previous Page
