Franklin Electric CERUS X-DRIVE CXD-003A-4V, Installation And Operation Manual

Page: 70 / 252

OPERATION
Control Options
70
Damper Control (HVAC Applications)
The VFD can provide a relay output to open a damper before starting a fan motor. When Damper Control is
enabled, the damper relay output is activated when the system receives a
RUN
command and the motor will
start based on the following configurations:
•
With Damper Limit Switch: If any Digital Input [IO–21] ~ [IO-28] is set to 34_Damper Limit Sw and the VFD
receives a
RUN
command, the damper relay is activated and when the damper limit switch is closed
(damper is fully open and DI is activated), the VFD will start the motor.
If the limit switch is not closed within the
Damper Time Delay [IO–37]
, the VFD will trip on Damper Fault. If
at any point during run mode damper limit switch is open for more than 2 seconds, the VFD will trip on
Damper Fault. VFD will try to restart based on the retry number setting
[PROT–10]
.
• Without Damper Limit Switch: If no Digital Input is configured for a damper limit switch and the VFD
receives a
RUN
command, the damper relay is activated, and when
Damper Time Delay [IO–37]
is complete
the VFD will start the motor. There is no damper fault detection because there is no damper limit switch
feedback.
NOTE: If any other run delay timer is set and the VFD receives a RUN command, the damper relay will start
after the first run delay timer expires.
During run mode, the damper relay stays activated. When a
STOP command is received, the damper relay will
be deactivated only in VFD stop state. If stop mode is set to deceleration, the relay will be deactivated after
VFD reaches zero speed (0.00Hz).
Set the following parameters to use the Damper Control function:
Damper Mode [IO–36]: Enables or disables damper mode. When enabled, the damper relay is activated
before every start, including auto restarts.
Damper T-Delay [IO–37]: Provides a run time delay without a damper limit switch; or, provides a Damper
Fault delay for systems that include a damper limit switch. The delay should be greater than damper open -
ing time.
Damper Output Terminal [IO–47] through [IO-49]: Connect the damper actuator to one of the Relay Out -
puts (RA1–RA3), and set the corresponding parameter to 38_Damper Output .
Damper Limit SW Terminal [IO–21] through [IO-28]: If the system includes a damper limit switch, connect
the switch to one of the Digital Inputs (MI1–8) and set the corresponding parameter to 34_Damper Limit SW .
Auto Restarts [PROT-10]: The number of times the VFD will try to restart after a fault.
Auto Retry Delay [PROT-11]: The time delay before the VFD attempts to restart after a fault.
Fireman’s Override
Fireman’s Override (FO) provides the ability to force the drive to run exhaust fan to purge smoke from fire in
the building by activating FO digital input. This mode is available for Basic and Exhaust fan applications.
In FO mode, if
Damper Mode [IO–36] is enabled, the damper relay output will be activated, but Damper T-Delay
[IO–37]
will reduce by half before VFD starts. The VFD will not monitor a Damper Switch, if present, and no
damper faults will be available. Set the following parameters to use the FO function:
FO Input Terminal [IO–21] through [IO-28]: Connect the FO switch to one of the Digital Inputs (MI1–8) and
set the corresponding parameter to either 32_FO with RUN Cmd or 33_FO w/o RUN Cmd .
FO Enable [IO–29]: Enables FO in either Forward or Reverse.
FO Frequency [IO–30]: Setpoint for non-PID operation during FO.
FO Fault Retry [IO–31]: Number of fault resets allowed during FO.
FO Retry Delay [IO–32]: Delay until restart during FO.