system shall also supervise the operation of the fuel-air equipment
associated with fuel oil burners. It shall accept operator commands and,
if the required permissives are met, perform the required operation.
Equipment shall be continuously monitored, and any deviation shall be
alarmed while the system either corrects the deviation of shuts down
equipment as necessary to avoid hazardous furnace conditions or equipment
damage. The system shall monitor the operation of the fuel equipment and
if the equipment fails to respond to command from the burner control
system, the equipment trip sequence shall be initiated. Indications shall
be provided to allow the operator to determine the equipment which
initiated a trip of fuel equipment. Tripped equipment shall be
successfully shut down before reset of the trip is permitted. The burner
control system shall include a fuel safety subsystem which shall include a
master fuel trip (MFT) system, ignition oil trip system, and main fuel oil
trip system. Each system shall include a hardwired relay which may be
directly operated from the operator insert panel. Inputs to the MFT shall
include, in addition to those associated with the burner control system,
those that are required to provide overall HTW Generator protection. Also,
the system shall interface with the combustion control system to position
and monitor devices for startup and shutdown which are normally modulated
during on-line operation. The burner control system shall be designed to
operate reliably and to minimize the number of false trips.
2.4.8.3
System Functional Requirements
a.
Operating Modes: The operator shall have the responsibility for
initiating the start and stop sequences listed below. Once
initiated the burner control system shall automatically place the
oil burner in service or remove it from service. The steps each
of which require operator initiation are:
(1)
Purge.
(2)
Igniter control.
(3)
Feeder control.
(4)
Main oil burner.
b.
Furnace Purge and Boiler Monitor: The furnace purge control shall
incorporate prelight off and post purges of the furnace to insure
that the HTW Generator is free of any accumulation of
combustibles. Completion of the furnace purge shall be indicated
to the operator after which the operator shall reset the master
fuel trip relay. A furnace purge shall be required on any master
fuel trip. The HTW Generator monitor shall prevent starting any
fuel equipment if the furnace firing permissives are not met. The
furnace purge control shall provide indications to the operator of
the status and the progress of the furnace purge. Permissive
indications shall be extinguished when the MFT relay is reset.
c.
Igniter Control: An igniter group consists of all the igniters
associated with a main oil burner. Igniters associated with a
burner group shall be controlled from a separate electropneumatic
igniter control package. Sequential starting of igniters between
burner groups shall be provided. Igniters associated with a
burner group shall be started and stopped from the insert panel
and local pushbuttons. An igniter fuel trip (IFT) first out
indication shall be provided to indicate the initiating cause of
SECTION 15555A
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