Silencing the DOTL

Door Open To Long (DOTL) sounders are used at a door to warn when the door has been left open longer than a pre-set time. They are also sometimes used in large retail stores with secure fire exits to alert staff if a customer opens the door.

The problem is that in the event of a fire alarm the DOTL alarms will automatically sound when the fire trip drops the lock power or the doors are left open. This can be confusing for evacuees and they may hesitate to use that exit. In a false alarm the DOTL sounders are downright annoying and inconvenient.

The solution is to fire trip the DOTL sounders. When designing your power distribution you should wire the DOTL sounder power from a fire tripped output of the PP8FR. They will continue to work as normal until the FIP is activated. Using this method will not affect alarms being generated in the in security software.

PP8FR DOTL Connection


This requirement is now being built into many designs and specifications.


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