Greenheck Vari-Green Control - Constant Pressure Indoor (474766) - Manual (Page 6)

6
Cutout Percent, Parameter P06
(Fan inlet control only)
Factory Default = 20%
20% = Cutout disabled, fan on continuously.
20% to 100% in 0.1% increments
The cutout feature can only be used if the system
utilizes powered fans such as bathroom fans or
dryers. It will not function properly if passive devices
are installed in the system such as motorized
dampers.
The cutout percent needs to be set if you would like
the exhaust fan to turn off when there is no demand
on the system. The default value is set at 20%. If the
exhaust fan is required to operate at all times, leave
the cutout percent value at 20%.
When the output percent is less than the cutout
percent, the cutout timer is activated (The timer
value is in parameter P07). After the time has
elapsed, the fan will shut off.
Note: A cutout percent value is only valid for a
discreet pressure set point. When the pressure
set point is changed, the cutout percent value must
be adjusted as well. It is recommended that you
make sure your pressure set point is correct before
continuing.
To set the cutout percent value, the following steps
need to be followed:
• Set normal operation and verify the system is
maintaining the desired pressure set point with
no other equipment (dryers, bathroom fans, etc.)
operating.
• After the pressure has stabilized at the set point,
press the Down/Decrease button to show the
percent output voltage. Take note of this value.
(The value will fluctuate slightly within +/- 2%. A
mental average will be adequate.)
• The recommended Cutout Value is 1-2
percentage points above the value you noted
in the previous step. See above for a graphical
representation.
When the system is running and the output percent
is less than the cutout value, the LED will flash.
After the cutout time has elapsed, the fan will turn
off. When the fan turns off, the display will show
“OFF” and the LED will flash.
Parameter Descriptions
Pressure Set Point, Parameter P01
Factory Default = -0.10 inches of water.
-1.00 to 1.00 inches of water in increments of 0.01
inches.
Auto Zero, Parameter P02
Factory Default = 0
0 = entry condition
1 = Perform Auto Zero
Auto zero sets the zero pressure reading of the
controller. Greenheck recommends performing auto
zero after installation and before first operation.
Place a piece of tubing from tubing connector “H” to
tubing connector “L”. Set value to 1 and press the
Enter button. The LED will turn white. Auto zero
is complete when the LED turns red. Remove the
tubing from the tubing connectors and reconnect the
pressure tap.
Factory Defaults, Parameter P03
Factory Default = 0
0 = entry condition
1 = Set all parameters to the factory default setting
Display Units, Parameter P04
Factory Default = 1
0 = Normal display is output percent
1 = Normal display is inches of water
Algorithm Gain, Parameter P05
Factory Default = 0
0 = Factory gains
1 = Gain set A
2 = Gain set B
If gain set 0 does not achieve stable operation use
one of the other sets to achieve stable operation.
Parameter Description Default Setting
P01 Pressure Set Point -0.10 inches of water
P02 Auto Zero 0 (see below)
P03 Factory Defaults 0 (see below)
P04 Display Units 1 (inches of water)
P05 Algorithm Gains 0 (factory gains)
P06 Cutout Percent 20%
P07 Cutout Delay Timer 30 seconds
P08 Override Output Percent 100%
P09 Pressure Input Filter 0 seconds
P10 Start Up Timer 10 seconds
P11 Fan-Inlet/Fan-Outlet Control 1 (fan inlet control)