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Operation and mechanisms
BFN(T) Remotely controlled spring return actuator
The spring return actuator BFN(T) is especially designed to operate fire dampers remotely. The BFN(T) variant is intended for fire
dampers with large dimensions (CRE60, CR2 with ø > 400 mm, CRS60 with ø > 315 mm or CU2, CU2-15, CU4 with B+H > 1200 mm. For
Markage FD with H of 400 and 600 mm or with H = 1200 mm (2 pcs) and with H = 2400 mm (in combination with BFT motor).
1. locking button
2. plug (ST)
3. access for manual resetting
4. thermo-electric tripping device (T)
1
3
4
2
Unlocking
∎
manual unlocking
: place the locking button on “unlock”. (In case of BFNT: the damper can alternatively be unlocked by pushing
the “test” button on the thermo-electric fuse)
∎
automatic unlocking
: the thermo-electric fuse reacts as soon as the temperature reaches 72°C (type BFNT).
∎
remote unlocking
: by interrupting the power supply.
Caution:
The thermo-electric fuse will not move the damper into its safety position (when the temperature reaches 72°C) if the motor
is not powered.
Resetting
∎
manual resetting
: turn the enclosed handle anti-clockwise. To block the motor, place the locking button on “lock”
∎
motorised resetting
: switch off the power supply for at least 10 seconds. Supply the actuator (respect the prescribed voltage) for
at least 75 seconds. The resetting stops automatically when the end of range is reached (damper open) - it takes about 60 seconds
to reset the damper - or when the power supply is interrupted.
Caution:
Do not use a drill or powered screwdriver.
Stop as soon as the motor is completely rearmed (end of range).
Caution:
The mechanism may never be tested on its own, without being attached to the damper. Such a test might damage the
mechanism or the operator might be injured.
