Blower Control Setpoints - Suction Pressure - Emerson Vilter PLC Operation Manual

Section 7 • Blower Configuration and Control Setpoints
• If suction pressure control is selected, the selected
suction pressure source will control the blower speed
command, and the selected discharge pressure
source will control load limiting and forced unloading.
• If discharge pressure control is selected, the selected
discharge pressure source will control the blower
speed command, and the selected suction pressure
source will control load limiting and forced unloading.
ANTI-RECYCLE
After a blower motor stops, the anti-recycle function will
become active. The motor will not be allowed to re-start
until the anti-recycle time is up. The anti-recycle func-
tion is blower specifi c: one blower in anti-recycle will not
affect the other blowers on the package. If the blower
package is started and a blower confi gured to run is in
anti-recycle, that blower will start once the anti-recycle
timer is up.

Blower Control Setpoints - Suction Pressure

The Blower Control Setpoints page 1 (Suction Pressure)
screen appears when navigating to "Blower Control
Setpoints" from the menu screen when Suction Pressure
control is selected. Setpoints for desired suction pres-
sure, PID Tuning, and Load Limits are accessible from
this screen. For more information and operational de-
scriptions, see section 2 "Operational Descriptions."
SUCTION PRESSURE CONTROL
• Target Suction Pressure: This is the desired suction
pressure the blower will try to maintain.
• Deadband: This is a range of pressures above and be-
low the Target Suction Pressure. Within this range,
no speed adjustments will be made.
PID TUNING
• Loop Update Time: This is the cycle time of the PID
controller.
• Proportional Gain (Kp): This is the proportional con-
stant of the PID calculation.
• Integral Gain (Ki): This is the integral constant of the
PID calculation.
• Derivative Gain (Kd): This is the derivative constant of
the PID calculation.
Blower Package PLC Operation Manual •Vilter/Emerson • 35391BLP
START UP
When multiple blowers are starting up, they start se-
quentially and increase in order. The offset dwell time is
what determines the amount of delay between starting
each individual blower. The purpose of this function is
to reduce the load on the electrical infrastructure when
necessary. Setting this time to "0" means that all blow-
ers confi gured to run will start at the same time.
In order to be able to start the blower package, the blow-
er confi guration must be valid. For the blower confi gura-
tion to be valid, all of the following rules must be met:
• At least one blower must be in service (selected to
run in preset speed or PID Speed Control).
• The selected suction and discharge pressure source
must be valid based on the confi guration of the pack-
age. (Example: to select a header pressure transduc-
er as a control source, the header pressure transducer
must be installed, to select a blower suction or dis-
charge pressure transducer as a control source, that
particular blower must be in service.
HIGH DISCHARGE PRESSURE LOAD LIMITS
• Inhibit Loading: Blower will not be allowed to increase
speed if Discharge Pressure rises above this setpoint.
• Unload At: Blower will begin continuously decreasing
speed if Discharge Pressure rises above this setpoint.
• Unload To: If forced unloading is active, the blower
will unload continuously until Discharge Pressure
reaches this setpoint.
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