control to provide fan load control in the bypass position.
2.14.5.2
Controller Environmental Protection
a.
Ventilation: Design controllers enclosed and ventilated for
installation in a moderately dusty area. Provide forced filtered
ventilation including fans, filters, controls and accessories
required for operation. Enclosures shall be operated under
positive pressure at all times. Provide filtered ventilating
openings and gasketed doors to prevent infiltration of dust.
b.
Heating: Provide electric heaters to prevent condensation in the
enclosure and to prevent low ingoing air temperatures that exceed
the equipment rating. Provide a low temperature alarm to sound
when enclosure temperature falls below required minimum
temperature. Provide contacts for remote annunciation of alarm
condition.
2.14.5.3
Method of Control
Supply each controller from an electrically operated air circuit breaker or
motor starter. Controller ventilation and heating shall be from another
circuit.
a.
Start Signal: Closes the electrically operated air circuit
breaker or motor starter to energize the controller. Controller
shall accelerate fan to operating speed. Fan speed shall be
controlled from the load control signal.
b.
Stop Signal: Opens electrically operated air circuit breaker or
motor starter to deenergize the controller. Upon deenergization,
controller control system shall revert to stop condition.
c.
Boiler Feedwater Pump Speed Control System: Matches pump
discharge to system demand and maintains a system header pressure
controlled to the set point values. Provide Manual/Automatic
control stations for master pressure and for each boiler feed
pump. Provide indicators for feedwater header pressure and
individual boiler feedwater pump flow.
2.14.5.4
Variable Speed Motor Controller
Conduct burn-in tests for at least 50 hours at rated conditions. If a
component fails during burn-in test, replace it, and run test again on
entire assembly for another 50 hours. Burn-in test shall not be complete
until entire assembly has operated for 50 hours without failure.
2.14.6
Valve Actuators
[Electrically] [or] [pneumatically] operated and designed so that valve may
be manually operated by removing drive pins. Actuators shall be operated
by push button control. Locate one push button at a position adjacent to
the valve. Locate a second push button within the boiler control room.
Provide a valve position indicator utilizing indicating lights. A green
light shall indicate valve is fully open and an amber light shall indicate
valve is fully closed. Both lights on shall indicate when valve is
partially open. [Provide torque limit controls to protect valve during
opening and closing for electrically operated valves.] Actuator electric
motor shall be totally enclosed, [_____] volts, [_____] phase, 60 Hz as
SECTION 15501N
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