I have encountered a 2 hour steel roller shutter door that operates by sliding horizontally across an opening. In this case a false alarm caused the door to close but it hit an obstruction. The system operates from the fire alarm, after a delay and with hooter sounding
The door has only a single limit stop at the end of its track. On hitting the obstruction the door continued to try and drive itself forward, resulting in its destruction, the drive forcing open the joints in the steel strips just like opening a corned beef tin.
There is a motor overheat cut out but this did not operate.
I have looked in various manufacturers leaflets and LPCB documents but cant find any reference to a need for any overload cut outs.
I would have thought it more sensible for an overload to be detected, the motor to stop and an audible alarm to sound to enable intervention by staff, and the shutter closed manually. As it is its totally wrecked and incapable of being closed or opened so cannot do its job, automatically or manually.
Please can anybody enlighten me as to whether there is any design standard that I have overlooked that should prevent this happening?
