15
/
19
Example installation of accesories
7.3. Electrical connections_____________________________________________________
Having properly located, placed and fastened the smoke exhaust fan, connect the equipment to the
relevant electrical system wiring. Lead the wiring through the gland and into the electric box on the fan
housing; then connect the wiring to the terminals according to the diagram shown in the box. The electrical
wire with the proper fire resistance rating is installed in standard by the manufacturer between the fan
motor and the electric box. Each fan motor must be connected to the electrical power system over a safety
switch. The safety level must be present according to the nominal current draw of the fan motor. The
protective earth shall be made according to relevant electrical engineering standards.
Once the smoke exhaust fan has been commissioned as a part of the system, measure the current draw
and verify that it meets the motor rating plate data. The smoke exhaust fan current draw in steady operation
must not exceed 1.1 times the current ratings.
The electrical power supply from the control cabinet to the fan power junction box must guarantee
uninterrupted operation in the case of a fire. This can be achieved with high temperature resistant wiring
or with protective tubing and proper safe routing of the electrical power system. No external
service/maintenance switches are to used, which is to prevent inadvertent shutdown of the smoke exhaust
fan (with the sole exception of the fan-dedicated service switch with remote indication of current circuit
switching). The smoke exhaust fan control cabinets must be powered directly from mail switchboards with
guaranteed uninterrupted power supply, even if the entire building is cut off from the power grid. If a main
fireman's switch is installed to isolate power from the entire building, the smoke exhaust fan power supply
must be independent from that solution and assure normal operation in the case of a fire.
If the system uses the service switch, install it outside of the fan casing, i.e. at a min. distance of 9 cm,. on
a bracket bolted to e.g. the fan casing flange [see the figure below].
Type PK counterflanges
Seal with HT silicone
Type KD flexible joint
Type KD flexible joint
Direction of flow
Type SW bottom foot
Type AM vibration
damper
Type KS automatic non-return
damper
