24V Isolated Failsafe Monitoring Unit

Order code: BF391 Category: Fire Alarm Ancillaries

Allows I/O devices that may not be compatible with the PSU failure requirements of BS 7273-4 Cat A to comply.
Is supplied on a single gang plate with an onboard isolating End of Line Unit (EOL) and normally energised 24V 3A rated relay.
Provides failsafe operation per BS 7273-4 Cat A, B & C requirements for all compatible I/O units.
Provides failsafe operation per BS 7273-4 Cat A B & C requirements for multiple coincidental loop failures (sometimes required in a specification above and beyond the requirements of BS 7273-4) for all compatible I/O units.
Accommodates I/O units sited inside or outside the 24V Aux enclosure (I/O units sited remotely require a BF390 EOL unit to maintain the failsafe function).
Provides complete galvanic isolation between the fire alarm system and the door release system.
Provides (where allowed) failsafe manual door release monitoring to BS 7273-4 Cat A utilising a single T&E cable for multiple manual operating points such as free swing doors.
Click here for Wiring Diagrams & Tech Specs.
Ask for a copy of our Engineering Note on BS 7273-4 detailing what the standard does and does not require.

Indicators	Energised indicator off indicates the BF391’s relay is in its de-energised, door released state., Energised indicator when lit green confirms the door release system is in its normal, door retained, energised state., Off/Fault indicator confirms the I/O unit has entered the door release state or there is a short or open circuit fault on the monitored wiring., Will also flag the flag the complete failure of the fire alarm system.
Product dimensions (mm)	85 W x 85 H x 30 D mm (Can be mounted on a standard UK 25mm single gang flush or surface back box).
Construction & finish	Plastic.
IP Rating	IP41.
Dimensions	87 W x 87 H x 28 D mm.
Weight	84g
Operating conditions/temperature	-0ºC to +40ºC. Max. relative humidity 95% non-condensing.