11
Installation, Operation & Maintenance Manual
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OPERATION
Dampers
Most dampers are opened and closed automatically via actuator with signal provided
by the controller, however some may be manually operated via a lifting handle at the
side of the damper.
Fans
Fan switches on the front of the control panel have 3 settings: Auto, Off and Test.
‘
Auto
’ will enable the fans when there is a demand from the controller, which may be
set via BACnet or local timeclock, dependent upon the controls configuration. This is
the normal mode of operation.
‘
Off
’ will disable the fans so long as other criteria is satisfied (such as a electric
heater fan run-on operation has been completed, and inverters, if applicable, are set
to automatic mode). To ensure the fans will not run during a maintenance routine,
they must be isolated using the main fan isolators mounted on the exterior of the
unit in the section where the fans are physically located. If the fans are operated via
inverters, it is recommended to switch off the main isolator to the unit before using
the fan isolators to prevent the inverters recording a fault and requiring a reset.
‘
Test
’ is for air balancing purposes only. Each unit may have a different
configuration. However, generally, ‘Test’ mode will fully open any fresh air and
extract dampers, fully close any recirc dampers and run the fans at a speed which
can be set by a speed potentiometer connected the control panel, an inverter control
pad, or through a software setting which can be set via touchscreen if applicable. It
is not recommended to run the unit in ‘Test’ mode, other than for air balancing
purposes, otherwise the unit will not operate correctly.
Inverters
Fan inverters can be controlled via a control pad installed inside the control panel
interior, if applicable. Generally, there is a control pad for each fan. However, in some
cases, several fans may be run from one control pad.
‘
Auto
’ will enable the fan when a signal is received from the controller and run at
speeds determined by a combination of the settings in the inverter and a control
signal. This is the normal mode of operation.
‘
Hand
’ will run the fan at the speed set on the control pad, which is a frequency in
Hz, limited by the settings. This can be manually changed using the up and down
arrows on the keypad to speed up and slow down the fan accordingly. This can be
useful for air balancing purposes.
‘
Off
’ disables the fan.
There may be occasions when a fault is shown on the inverter control pad. If you
notice a fault on the inverter, make a note of the fault code and message.
The most common fault occurs when power to the fans is isolated before the
inverters are isolated. The fan will not run until the fault is reset on the control pad.
This can be rectified by restoring power to the fans by switching the isolator back on,
then pushing the ‘Reset’ button on the control pad when the fault is active. If the
fault does not reset, it may be necessary to turn off power to the main isolator, then
turn it back on again.
For all other inverter faults, please refer to the ABB manual.
