View Full Version : How to Have the Lights Shut Off When the fire alarm goes off

07-27-2010, 07:03 PM
The fire marshal is saying that we all of our lights to shut off when the fire alarm goes off. Does anyone else have to do this and how do I do this?

Thanks so much!


Karl Fields
07-27-2010, 07:43 PM
Typically the FM would want a system that, when activated, turns ON house lights, and turns off all sounds and moving props. Maybe even monitored or auto call the FD.

Because it is a life/safety issue, the FM is not going to allow allow you to use a home built system. A Google search on "fire alarm control system" should net you 3 or 4 million sites :)

The fire marshal is saying that we all of our lights to shut off when the fire alarm goes off. Does anyone else have to do this and how do I do this?

Thanks so much!


Dark Attraction
07-27-2010, 11:06 PM
This is known as a "shunt" switch/circuit. The fire alarm control panel has a control relay that is activated when an alarm is triggered. This in turn powers a separate high-voltage relay which powers the circuit/circuits that have your special effects... fog, strobes, sound, or anything disorienting.

The alarm relay typically has both normally open/normally closed circuits so it can also be wired to turn on emergency lighting while shutting everything else off.

If you use battery powered emergency lights, you can plug them into the shunt circuit and they will turn on when the power is cut to everything else. This is the most reliable method as far as I know.

07-28-2010, 07:47 AM
We had to put shunts in last year at the hotel I did my haunt. They pulled them from above from the ceiling mounted detectors.

Mike Goff
07-28-2010, 02:42 PM
This is not a substitute for a shunt trip breaker, but you could have your white lights come on by using x10, interface.

I have mine set up so when the fire alarm goes off it gives an all lights on command, and when the security system goes off the lights strobe on and off.

Like I said, you should still use a shunt trip to kill the effects, and trigger the back up lighting.

If you go this route, it's best to stick with incandescant lighting, or use a plug in type appliance module for halogen, flourescent or CF.

07-29-2010, 12:57 AM
I know last year in Sacramento we got away with just having a full time person sit in the electrical room and would pull the main switch if the fire alarm went off. I'm going to try this same tactic this year, but I have a feeling the FM wants this shunt device you're all talking about. Thanks for the help, I'll look into it.

07-29-2010, 11:47 AM
Hmmm, our fire marshal accepted our plan to have an employee in the electrical room full time to shut off the power if the alarm goes off. This will also turn on the egress lights. That may be useful information to anyone who wants to get around re-wiring and plugging into the fire alarm.

Mike Goff
07-29-2010, 03:35 PM
we used to do this too, if you do the math, it's cheaper to go with the shunt trip breaker, unless you can find a volunteer to baby sit the load center.

good luck

07-29-2010, 08:26 PM
Well. we are only open for 18 days which is 72 hours to be manned = $720. Otherwise our FM was requiring that we submit plans for the new change and have it done by a professional. This was the easier solution I suppose for our purposes and no stress if the plans wouldn't approve.