TM 5-810-15
process fluids is to be run in control panels. All
balancing for transfer; and have antireset windup
field wiring entering or leaving control panels is to
characteristics. Operator stations with set point will
be connected to terminal blocks with spare termi-
indicate set point in engineering units. Operator
nals provided. The items to be mounted in the
stations with ratio or bias are to indicate the
auxiliary panel will include hardwired main fuel trip
magnitude of the ratio or bias at all times. Operator
(MFT) pushbutton, fan trips, drum level indication,
stations are to indicate the measured variable on a
soot blower controls and annunciation of critical
continuously in engineering units and will indicate
items. The annunciator should include items listed
station output continuously in percent. The
below.
indications on a station should be consistent with
1. Main fuel trip (MFP)
all other stations such that all final control elements
2. Drum level high-low.
move closed to open from zero to 100 percent. For
3. Furnace pressure high.
hardwired operator stations, the position of final
4. Boiler FW pressure low.
control elements will not change when an operator
5. Control system power failure.
station is disconnected from or reconnected to its
(2) Panel mounted control system. The
plug-in cable. Changes in ratio or bias settings will
control and auxiliaries panel where used will
not cause a process upset.
include operator stations, recorders, indicators,
(2) Records. Records will be kept for the pa-
equipment start-stop controls and annunciation.
rameters indicated in table 9-4. Records will be
The arrangement of the panel will not be addressed
stored on floppy disks when a control console is
here since panel arrangements are normally based
used. The operator will have access through the
on the preferences of operating personnel and
CRT to display trends for parameter for which
management.
records are kept. When the operator interface
(a) Control panel construction. Control
utilizes boiler and auxiliaries panels recorders will
panel construction must conform to the
be used. Recorders may be strip chart recorders or
requirements of the National Electrical Code, the
circular chart recorders. The recorders will have
National Fire Protection Association, and NEMA
scale markings consistent with the measured vari-
standards. Panels will be constructed of steel plate
ables and associated field transmitters. The use of
with adequate internal reinforcement to maintain
circular chart recorders will be restricted to steam
flat surfaces and to provide rigid support for the
pressure, steam flow, air flow, and exit gas tem-
instrumentation to be installed. The panel interior
perature. Circular chart recorders will not be used
will have adequate bracing and brackets for
when conservation of panel space is critical or
mounting of equipment to be installed within the
desirable. Allowances should be made to provide
panel. A walk-in door for access to the panel
spare pens for future use.
interior will be provided on both ends of the panel
(3) Indicators. Indicators will be provided for
where possible and on at least one end of the panel.
the parameters shown in table 9-4. When a control
Electrical outlets will be provided in the panel. No
console is utilized the parameter will be displayed
pressure piping of process fluids is to be run in
on the CRT. The display may be digital or graphic
control panels. All field wiring entering or leaving
and the displays should have scale markings
control panels is to be connected to terminal blocks
consistent with the measured variable and
with spare terminals provided.
associated field transmitter. When indicators are
located on a panel the indicators may be digital
auxiliaries panel or control console will provide
indicators or analog indicators. Digital indicators
operator interface required to properly control and
will have Light Emitting Diode (LED) uniplaner
monitor the operation of the boilers and auxiliary
numerals, zero instrument zero drift with time, and
equipment in the steam plant. This will include
0.1 percent Full Scale (FS) or less span drift per
operator interface to stations, recorders or trend-
year. Analog indicators will have vertical edgewise
ing, indication, equipment start/stop controls, and
scales, plus or minus 2 percent full scale accuracy,
annunciation. Table 9-4 summarizes the instru-
and scale markings consistent with the measured
mentation requirements for the operator interface.
variable and the associated field transmitter.
(1) Operator stations. Operator stations are to
Integrators are shown in table 9-4 and should
be provided as shown in table 9-4. Operator
include the signal converters necessary to provide
stations on control consoles will be accessed
scaled integrated readings. Integrators will have at
through the CRT or through individual operator
least six digit readout.
station on control panels. Hand automatic operator
(4) Equipment start/stop controls. Equipment
stations will provide bumpless transfer from hand
start/stop controls will be provided for all major
to automatic and automatic to hand without manual
9-20
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