WEBVISION™
61
95-7769—01
FCU Fan
Purpose
Define fan operation.
Mode
Configuration can be performed with the wizard Off-line or
On-line.
Procedure
1.
Click the
Fan
button on the left pane to open the
Fan
Configuration
page.
2.
Enter information into available fields.
3.
Click
Commit
to save the settings or
Reset
to revert to
the last saved settings.
4.
Click
Next
to display the
Switching Levels
Configuration
page or
Back
to display the
Equipment
Control Configuration
page.
FCU Fan fields
Output Options (continued)
Min Stage Off Time
Define the minimum off-time for control outputs configured for operation as staged outputs. This setting is particularly
useful for heat exchanger operation or compressor units. Each stage of the controlled output stays off for the minimum
period of time before the controller turns it on again. The selectable range is 0 to 600 seconds.
Valve Runtime
This configuration parameter has three different functions depending on the control output type selected in Control
Outputs:
(CONTROL OUTPUT TYPE = FLOATING) The value is the actuator run-time in the range 20 to 600 seconds.
(CONTROL OUTPUT TYPE = PWM) The value is the cycle period of the PWM output in the range 20 to 600
seconds.
(CONTROL OUTPUT TYPE = ONE, TWO OR THREE STAGE) The value is the minimum on-time for each of the
stages, for controlling compressor units.
Reheat
Options
Defines the control output level at which the electric reheat relay (relay 4) switches.
Switch Level
Define the control output level at which the electric reheat output switches on. Range 0% to 100%.
Use a setting of 5% where electric heating has priority over a water heating valve, for example, as the first heating
sequence. Or use for electric heating control only.
Use higher settings, for example, 90%, where water heating has priority over electric heating. Or when electric heating
is required during summer/winter changeover periods.
Hysteresis
Define the control output level (Switch level - Hysteresis) at which the Reheat control output switches off.
PWM
Options
Allows the full range of the PWM outputs to be configured. Many PWM-controlled devices cannot provide an output of
0% or 100% because a PWM output shows no switching at these percentages. Therefore, most PWM devices have a
minimum duty cycle and a maximum duty cycle between which they operate from zero to full scale. The fields here allow
you to configure the full range of settings. It is possible to swap the Zero and Full range values to achieve reverse
operation for a PWM output.
Zero
PWM % duty cycle for fully closed position.
Full
PWM % duty cycle for fully open position
Table 34. FCU Equipment Control Options. (Continued)
Name
Definitions
Table 35. FCU Fan Field Options.
Name
Definitions
Fan
General
Fan Occupancy
Configure the operation of the fan during occupied
periods.
Auto Mode
The fan is automatically turned on and off
according to heat or cool demand.
Continuous Mode
During the occupied period, the fan continuously
operates at least at the minimum speed. If heat or
cool demand requires a higher speed, the fan
automatically operates to the required speed. This
setting does not affect automatic fan operation
during standby and unoccupied periods.
Min On Time
Min Off Time
Fan
Interlock
Define the pre-run (Fan Run-up Time) and post-
run (Fan Overrun Time) times for the fan, when
fan interlock has been selected (Equipment
Control page).