SFPE Discussions

Automatic Sliding Doors

I take the attitude that occupant endeavours to exit a building are absolute (except for some care and detention occupancies). Occupants should be able to override any manual or automatic barrier to their exit.
Fire alarm systems have a few modes of failure that could result in failure of automatic release of doors and opening of sliding doors thus thwarting the absolute right of an occupant to escape from a building.
It would be nice to think that automatic doors could only fail 10 hours after a fire. There a known cases in NZ where the power supply to the automatic doors have been interrupted, for whatever reason, and the doors have continued operating until the battery goes flat. The length of time for the battery to go flat can be from a few seconds to a few hours depending on the maintenance and condition of the auto-door battery.
Most of the time, a single failure does not create a major problem. Very occasionally, disasters occur when there are multiple simultaneous failures.
I see the requirements of C/AS2 3.15.7 addressing situations with a fire event, or even an earthquake event, AND, a power supply failure or malfunction an automatic door.
If MBIE would be happy to rely on the built in battery backup (with no current testing regime) to reliably operate the automatic doors in a fire event then C/AS2 3.15.7 should explicitly say so. (Why do we test fire alarm system power supplies monthly?)
I am currently unaware of any test switch that interrupts the power supply to automatic doors to determine if the requirements of C/AS2 3.15.7 are complied with.
I suppose the IQP’s are pulling the circuit breaker to the doors and waiting 10 hours to see if the doors can be opened (yeah right).
If C/AS2 3.15.7 is wrong - it needs to be changed. If C/AS2 3.15.7 is right it needs to be enforced.
I believe C/AS2 3.15.7 is substantially correct. It provides for a viable operational testing and maintenance regime which is more like to provide reliable escape routes than the currently commonly used “pray and hope” approach.

For those who don’t have it, NZS4239 states
5.3.2 Operation
In the event of an emergency condition, power failure, or the activation of required fire or smoke alarm anywhere in the building, the automatic doors shall -
a) fully open automatically and remain open for the duration of the emergency; or
b) be able to be opened by hand under a force of not more than 110N.

I assume the door people rely on b for getting away with it. I note the 110N is higher than C/AS with sliding doors (67N?) and wedging your fingers in the crack doesn’t comply with D1 for door hardware.