20
External pre-heating element
It is possible to purchase an external electric pre-heating element for frost protection of the ventilation unit.
The electric preheating element is mounted in the outdoor air duct before the unit with the necessary temperature sensor.
If it is desired to see the actual outdoor air temperature on the control panel, the temperature sensor T1 / T8 must be led out into the
duct before the preheating surface.
.
It is important that the sensor is placed at least 32 cm from the preheating element to achieve correct regulation.
The pre-heating element has a three-step safety system that prevents overheating.
1. An operating thermostat regulates the heating and ensures that the supply air temperature does
not fall below -1 °C
2. Should the temperature exceed 50 °C, a max. thermostat switches off the pre-heating element.
(If installed vertically with downward airflow, the pre-heating element switches off at 70 °C)
3. A safety thermostat switches off the pre-heating element if the temperature exceeds 100 °C.
Then, you must reset it manually.
Minimum airflow at Ø160: 110m
3
/h.
ATTENTION
The heating element must be insulated with a fire retardant insulation material. The cover of the connection box,
however, must not be insulated.
Dimensional drawing:
Positioning options:
7
N L
8
T
T1/T8
1x230V ~ 50 Hz max. 16A
Min. 32 cm
276
370
~50
~50
71
Ø160