airmaster CV 80 - Airmaster Internal Control Functions; Low Temperature Protection Function; Preheat Function for Cold Conditions

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5.7. Boost
The boost function can adjust the airow temporarily and
is programmed to use some xed control voltages for the
supply fan and the exhaust fan respectively. It is possible
to adjust the control voltages for the fans independently
of each other if unbalanced ventilation is required.
The function is activated by an external switch that is
connected to an input terminal at the main box.
The air handling unit stops the normal operation and
activates the boost function when the contact closes. If
the signal is disrupted, the unit will return to the previous
operating mode (after-run time is factory set to 0 min). In
case the air handling unit is stopped the boost function
will start it.
5.8. Control Using an Analogue BMS
An air handling unit can be controlled using an A-BMS (ana-
logue Building Management System), which can start and
stop the unit, and regulate air ow and inlet temperature.
The A-BMS can be tted with an alarm signal (alarm contact)
from the air handling unit, when the unit registers an
internal alarm.
The A-BMS will start the unit using a start/stop signal and
then control air ow and inlet temperature.
It is also possible to start and stop the unit using an A-BMS
and then operate and set it using the control panel. See also
“Installation manual - External connections”.
5.9. Cooling Module Operation.
The cooling module reduces the outside air temperature
before the air passes through the air handling unit.
The cooling module operates on demand, and is monitored
by the Airlinq control system. In general, the cooling mod-
ule will start if the room temperature is too high, or the
inlet temperature exceeds its setpoint for high outside
temperature.
When running, the cooling module adjusts air ow fully
automatically according to demand. If the air ow is manually
reduced to below the minimum necessary, there is a risk of
damage to the cooling module. Consequently, the control
system will stop the cooling module.
6. Internal Control Functions
Internal control functions run automatically, and inuence
air ow and inlet temperature. An internal control function
is shown under control panel menu point “Status”, or using
the Airlinq User Tool or Airlinq Service Tool.
6.1. Low Temperature (“Low Temp”)
The “Low Temperature” internal control function protects
the heat exchanger against ice forming at low outside
temperatures, and maintains the inlet temperature (IT)
when the temperature conditions are too low for the
standard parameters. The control function increases the
inlet temperature (IT) independently and/or protects the
heat exchanger by reducing the supply air and increasing
the extract air. It thus creates unbalanced ventilation. It runs
regardless of whether the unit has heating surfaces or not.
If the unit is tted with preheater and comfort heater, the
control system can maintain balanced operation even at
very low temperatures.
The control system function starts automatically when:
1. The inlet temperature (IT) falls 2 °C below the inlet
temperature setpoint
or
2. If there is a risk of ice forming on the heat exchanger.
6.2. Preheat
The Preheat internal control function ensures unit operation
at low outside temperatures, when the unit has an electric
preheater surface. The control system switches on the
heater automatically as required. The heating surface will
heat up the cold outside air before it reaches the heat
exchanger, preventing ice forming on the heat exchanger.