1.
Boiler master signal (Analog).
2.
Total plant steam flow.
3.
Totalized steam flow pulse.
d.
Controller shall be provided with protocol converter/gateway with
EIA ANSI/TIA/EIA-485-A multi-drop communications port for
controller LAN network interconnection to field panel controllers
[and to supervisory computer workstation.]
2.5.8
Boiler Master Controller
a.
Each boiler shall have a boiler master controller. This
controller shall control jackshaft in response to plant master
demand signal or in response to boiler pressure and local
setpoint. Primary analog output shall modulate jackshaft actuator
of boiler. Logic required to ensure that prepurge, postpurge,
lightoff and burner modulate cycles are handled correctly and
according to local regulation shall be the burner manufacturer's
responsibility. Controller digital display shall include the
following in their respective engineering units:
1.
Controller output.
2.
Natural Gas flow.
3.
Fuel Oil flow.
4.
Local setpoint.
b.
Controller inputs shall be:
1.
Plant master signal.
2.
Steam flow.
3.
Steam pressure (Analog).
4.
Natural gas flow (Analog).
5.
Fuel oil flow (Analog).
6.
Firing rate hold (Contact).
7.
Purge from flame safeguard system (Contact).
8.
Auto from flame safeguard system (Contact).
9.
Remote alarm silence (Contact).
c.
Controller outputs shall be:
1.
Jackshaft drive (Analog).
2.
Remote audible alarm (Contact).
3.
Flow pulse for natural gas flow totalizer (Contact).
SECTION 15561A
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