Cabling to AOV systems (Life safety)

We have a natural smoke vent system on a project where the main supply cable to the SVCP has been taken from a local DB and wired in SWA. These systems have a 72 hour back up for the life safety element and all power & control cabling from the inverter is wired in FP200. However, the AOV contractor has just informed us that the main supply should also be wired in FP and afford the appropriate protection. My question is should the main supply be installed in FP from the main panel board or can the protection be from just the local DB, bearing in mind that should the system 'fall over' the battery system will still give 72 hours of protection. Any insight would be appreciated.

Parents
  • I did one two years ago, 5 storey blocks of flats with sprinklers in the communal areas, and of course, lots of vents connected to the fire detection system, as well as dampers for the air ducting.

    I followed the Design, the 'Life Safety systems' were on a separate DB, fire separated in its own little room, with what should have been a totally separate supply from the street, but I found out the supply was taken off the main incoming supply cable, so the same supply for all intents, which is against the relevant Regs.

    Anyway, the wiring to the main panels and sprinklers pumps/controls was in FP rated SWA from the separate Life Systems DB. The wiring to all of the vent controls was in FP200 cable, but the 230v wiring to the individual vent contactors was in normal T+E or flex, fed from any local DB.

    I queried this a few times, but was told it was correct, in that if the supply is cut, the vents shut, so if the cable burns out, it will shut the vents even if the fire detection didnt work (that seems rather odd, and surely doesnt exist in any Regs explanation). Then there were the Firemans Vents, which when switched, open up the vents, these were all in FP200.

    So I'd say, yes, you may need to fit FP cable to supply any controls. It is a pretty standard requirement in Commercial contracts. Also, I'd be checking the supply requirements. As it has battery back up, that may not affect you, but the supply to the control panel must not be able to be switched off by non-instructed people , I've been to a place before where they say the fire alarm has been bleeping for a week, and find the supply circuit breaker has been turned off, as something tripped, - they actually turned things off, rather than turning things on when trying to reset it!

Reply
  • I did one two years ago, 5 storey blocks of flats with sprinklers in the communal areas, and of course, lots of vents connected to the fire detection system, as well as dampers for the air ducting.

    I followed the Design, the 'Life Safety systems' were on a separate DB, fire separated in its own little room, with what should have been a totally separate supply from the street, but I found out the supply was taken off the main incoming supply cable, so the same supply for all intents, which is against the relevant Regs.

    Anyway, the wiring to the main panels and sprinklers pumps/controls was in FP rated SWA from the separate Life Systems DB. The wiring to all of the vent controls was in FP200 cable, but the 230v wiring to the individual vent contactors was in normal T+E or flex, fed from any local DB.

    I queried this a few times, but was told it was correct, in that if the supply is cut, the vents shut, so if the cable burns out, it will shut the vents even if the fire detection didnt work (that seems rather odd, and surely doesnt exist in any Regs explanation). Then there were the Firemans Vents, which when switched, open up the vents, these were all in FP200.

    So I'd say, yes, you may need to fit FP cable to supply any controls. It is a pretty standard requirement in Commercial contracts. Also, I'd be checking the supply requirements. As it has battery back up, that may not affect you, but the supply to the control panel must not be able to be switched off by non-instructed people , I've been to a place before where they say the fire alarm has been bleeping for a week, and find the supply circuit breaker has been turned off, as something tripped, - they actually turned things off, rather than turning things on when trying to reset it!

Children
No Data