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CONTROL MENU
MENU ITEM
SOFTWARE
NAME ITEM
DESCRIPTION
ITEM RANGE
DEFAULT
VALUE
SPEED SPEED
The
SPEED
item is used to select the control output speed
(supply and general exhaust). When this item is selected, a bar
graph is shown on the display. There are 10 bars, each one
representing 10% of speed. Starting from the right side (+ sign),
10 bars displayed indicates maximum speed. This is the fastest the
controller will operate. 1 bar is the slowest the controller will
operate. The more bars displayed, the faster the control output.
1 to 10 bars
5 bars
SENSITIVITY SENSITIVITY
The
SENSITIVITY
item is used to select the integral dead band.
The integral dead band determines when the controller uses
integral control (slow control), and when the controller enters
PID control (fast control). When this item is selected, a bar
graph will be shown on the display.
There are 10 bars total, with each one representing 50 CFM.
Starting from the right side (+ sign), 10 bars displayed indicates
no dead band so the controller is always in PID control mode.
Each bar missing represents ±50 CFM of integral dead band.
The less bars displayed, the larger the integral dead band. For
example, with 8 bars displayed (2 bars missing) and an offset of
500 CFM, the integral dead band is between 400 and 600 CFM.
When the measured offset is within this range, integral or slow
control is used. However, when the flow offset falls below 400
CFM or rises above 600 CFM, PID control is enabled until the
unit returns within the dead band.
The
SENSITIVITY
item has a unique feature that when zero
bars are displayed, the unit never goes into PID control. The
control output is always a slow control signal.
WARNING:
When
SENSITIVITY
is set for 10 bars, the
system is always in PID control, which will
probably cause an unstable system. It is
recommended that
SENSITIVITY
be set at 9
bars or less.
0 to 10 bars
5 bars