available control systems. Bracketed text or
section denotes designer's options. The base level
of required controls is an integrated system of
local control and monitoring panels. An upgrade to
this system would include a remote supervisory
workstation to monitor and alarm functions of the
boiler plant via a network controller LAN.
**************************************************************************
a.
Boiler controller and plant master controller systems, and other
sub-control systems specified herein shall be provided by a single
control manufacturer.
b.
For multiple boiler installation, boiler No. 1 control panel shall
act as the plant master control and contain controls common to all
boilers. Interfaces between flame safeguard, combustion control
and burners shall be provided.
c.
System components shall be electronic, solid state, microprocessor
type. Control components shall operate on 120 VAC power.
d.
Analog signals to and from field-mounted devices shall be 4-20 mA
DC. Analog signals between rack or panel-mounted devices shall be
[4-20 mA] [1-5V] DC.
2.5.1
Instrument System
Instrument systems shall be powered by 120 volts alternating current, 60
Hertz or 24 volts direct current 2-wire system. The 24 volts direct
current powered systems shall receive power from the central control
system. Instrument enclosures shall conform to Section 16402 INTERIOR
DISTRIBUTION SYSTEM. Transmitter output signals shall be 4 to 20 mADC.
2.5.2
Indicating instruments shall have the normal operating point marked in
green on instrument. Transmitters shall include output meters in
integrally mounted housings. Calibration shall be set by manufacturer, and
adjustment access shall be internal only.
2.5.3
Factory Tests
Instruments, units, and other accessories shall be inspected, calibrated,
and tested. Calibration shall be to manufacturer's standard for accuracy
of input versus output. Certificates of inspection, test, and calibration
tags ensuring compliance with standards shall be submitted with
instrumentation. Control system manufacturer shall configure, program,
stage, and burn-in the control system prior to shipment to construction
site. Programming of configuration and constants data shall be performed
at this time, and stored on disks. Burn-in shall be for a minimum of 10
days of continuous operation. The Government reserves right to witness
factory tests. A thirty-day advance notice shall be given to the
Government prior to commencing any factory tests.
2.5.4
Sequence of Operation
a.
Plant master controller shall vary firing rate of [all] boiler[s]
[in parallel]. Plant master controller shall receive a pressure
signal from main steam header and generate a signal to drive
SECTION 15561A
Page 41
Previous Page
