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ELECTRIC HEATER
The safety switches must be switched off and locked after the unit has been switched
off before starting any service work.
Function:
The function of the electric heater is to heat supply air to the desired outgoing tem-
perature. The heater consists of a number of electric coils (stainless steel) for 3 x 230
V and 3 x 400 V. The electric heater is equipped with two overheating guards. One is
automatic return (approx. +60 °C), and the other is permanently installed fire protec-
tion (setting approx. +120 °C), with manual reset GT9, designed to prevent overhea-
ting when airflow is insufficient or there is a fault in the unit.
It is very important for operating reliability and fire safety that the electric heater is
carefully inspected and kept in good condition. Dirty parts can lead to odours and, in
the worst case, even cause a fire. The electric heater is blocked, via a pressure monitor
in the GP5 supply air duct, so that it cannot be operated unless the fan is running.
Therefore, do not switch off the voltage to the fan using the switch disconnector.
Instead, use the control panel. Note that the fan is equipped with delayed stop for coo-
ling down the components.
Check:
• That there is no dust or other flammable substance in the heating part
or on the components.
• That the elements are not damaged.
• That the airflows are normal and at least 1 m/s.
• That the electric heater’s automation is working.
Action:
• Vacuum and dry clean when needed (at least twice a year).
• If a component is defect, it must be changed.
• Reprogram the control equipment so the air speed is at least 1 m/s.
• Check all electrical cables. Consult a service technician when needed.
Resetting triggered overheating protection:
The reset button is visible on the service side of the electric heating coil. However,
before the unit is reset the reason for the fault must be corrected. The wiring diagram
for the electric heating coil is located inside the electric heater.
Unscrew the screws to dismantle the electric heater.
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