Swegon GLOBAL LP FW Operation And Maintenance Instructions Download

Page: 18 / 60

Operation and maintenance instructions – v2.8.8 & 2.7.3

5.1 OPERATING MODE

There are five main operating modes. The operating
mode determines how the airflow or the fan torque
is modulated. The default operating mode is Airflow
control. Exceptions are units equipped with backwards
fans without the Constant Air Kit or if Constant Torque
mode has been selected in the product setup menu, in
both cases it is the fan torque that will be controlled and
modulated.

5.0 Functions

In all the operating modes, the supply fan(s) will operate
as per the assigned mode and parameters. The exhaust
fan(s) will operate according to the chosen percentage
of the supply fan (%EXH/SUP ratio). The five main
operating modes are:

•

1 - Airflow control:

  Flow control involves operating the air handling unit to keep the pre-set airflow constant. The speed of the
  fans is automatically regulated to provide correct airflow even if the filters begin to become clogged, air
  terminals are blocked, etc.  Airflow control mode is advantageous, since the airflow always is exactly as it was
  from the beginning. It should however be noted that everything that increases the pressure drop in the
  ventilation system, such as blocking of air terminals and dust accumulating in filters, causes the fans to run at
  a higher speed. This results in higher power consumption and may also cause discomfort in the form of noise.
  There are three airflow setpoints to be configured by the user (m³h K1, m³h K2, m³h K3).

•

2 - Torque control:

3 torque setpoints to be configured by the user (%TQ K1, %TQ K2, %TQ K3). The setpoint is configured

  in % of the maximal torque. The torque control allows to vary the fan speed automatically, to
  provide a variable airflow for demand controlled systems (DCV). This allows for demand controlled fan operation
  or fan optimisation by a BMS system, mostly used in multi zone systems.  This operation mode can partially
  replace the constant pressure control when a duct pressure sensor hasn’t been installed.

•

3 - Demand control 0-10V:

  The airflow is controlled by a 0-10 V signal. The control signal is connected to terminals K2&GND. The assigned
  supply airflow is set as a percentage of a linear 0-10 V signal. The user defines the link with 4 parameters: Vmin,
  Vmax, m³h   Vmin and m³h   Vmax, applied to the following diagram. The demand control mode is also

  available for modulating fan torque instead of airflow (relevant for backwards fans units without Kit CA).
  The principle is identical to the demand control mode operation with the difference that Vmin and Vmax are
  connected to a %TQ instead of m³/h.

•

4 - Pressure control:

The airflow automatically varies to provide constant pressure in the ducting system. This type of control is

also called VAV control (Variable Air Volume).

Pressure on supply: the airflow of the supply fan(s) is modulated to maintain a certain pressure Setting

  constant. The pressure is measured by a pressure sensor located in the supply air duct.
  Pressure on exhaust: the airflow of the exhaust fan(s) is modulated to maintain a certain pressure Setting
  constant. The pressure is measured by a pressure sensor located in the extract air duct.

•

5 - MODE OFF :

This stops the AHU