- Start auxiliary oil pump and allow to run for 3 minutes.
- Open unloading valve and close inlet butterfly valve.
- Start main drive motor.
b.
When the motor reaches full speed, the inlet butterfly valve shall
open and the unloading valve shall close. The inlet butterfly
valve shall open to a minimum set point slightly above the surge
point. The inlet butterfly valve shall then be controlled by a 4
to 20 mA dc signal from the control system to maintain the desired
flow. When the shaft-driven main oil pump reaches specified
pressure setting, the auxiliary oil pump shall stop.
c.
Upon turning the selector switch to the off position, the control
panel shall sequence shutdown of the blowers as follows:
- Open the unloading valve and close the inlet butterfly valve.
- De-energize the drive motor.
d.
When the shaft-driven oil pump pressure drops, start the auxiliary
oil pump and allow to run for [30] [_____] minutes to provide for
post lubrication and cooling.
2.3.11.3
Indicators
The following indicators shall be provided, mounted on the control panel:
a.
Inlet and outlet pressure gauges.
b.
Valve position indicators for the unloading valve (open or closed)
and the inlet butterfly valve (in percentage open).
c.
Inlet air volume in cfm indicator. The indicator shall be an
ammeter measuring the current draw of the blower motor and
calibrated so that a given amount of current draw shall correspond
to the volume of air being handled by the blower.
d.
Lights to indicate the auxiliary oil pump is running and is as
required for the protective devices.
2.3.11.4
Blower Protective Devices
a.
All blower protective devices, upon alarm condition, shall cause
immediate de-energization of the motor, shall initiate the
automatic shutdown sequence, and shall provide audible and visual
alarm indication. Positive displacement blowers shall be equipped
with automatic pressure relief valve.
b.
Bearing temperature protection consisting of encapsulated
temperature switches in milled slots directly over each blower
bearing, a control relay, a selector switch and test pushbuttons,
and a running light shall be provided. Upon excessively high
temperature of any bearing, the system shall initiate protective
shutdown and shall indicate which bearing is affected.
c.
A protective device shall be provided to prevent the blower from
SECTION 11375A
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