Occupancy sensors in an electrical/mechanical room

[David Coon]

It has been inquired about before in this forum. It was declared that it "Shall not be controlled by automatic means only" (NFPA 70E). Does that mean you can install one in an electrical/mechanical room, if it has a by-pass function? I've purchased occupancy sensors in the past that have a slide switch (off-auto-on). If you took the statement at face value it implies a singular function of automatic only. The sensor I mentioned wouldn't be only automatic means. It would have the additional means of a manual override feature.

 

[charlie b]

If in addition to the occupancy sensor, the lights can be turned on manually in such a way as to prevent them from being turned off by the OS, or by a "sweep off at the end of the day timer," or by any other automatic means, then you will comply with the rule. That said, I can't think of any reason to use an OS in an electrical or mechanical room. You have to provide a manual switch anyway, so why go through the added expense of an automatic control?

Welcome to the forum.

 

[chris kennedy]

"Shall not be controlled by automatic means only" (NFPA 70E).

Also in the NEC, 110.26(D).

Welcome to the Forum.

 

[David Coon]

Thank you for your feed back. Most of time, trips to our multiple electrical/mechanical rooms don't involve work that would risk someone's safety ​if the the lights were to go off. People currently tend to leave the lights on when they exit the room. The sensors would be in the auto mode most of time. If there is need/risk, the lights would be manually turn on before the work commenced.

 

[dclauria]

We have been wiring assisted living homes for the last few years, and the engineer always puts on the plans 3 OS in a upstairs service/mechanical/storage room approximate 15' x 50'.
No local inspector ever seems to know what rooms they are actually required in. They just say "do what the prints show."

Are they required in a mechanical room if it's not a publicly accessible area? The door is always locked.

Thanks for your input. By the way, I'm in Michigan.

 

[Electric-Light]

What does "automatic means only" anyways? If it was controlled automatically as part of the building control system, that is clearly automatic only...

However, if it's on always-on circuit and you use a vacancy sensor (does not turn on automatically. Button mush be pushed to activate, turns off after xx minutes or when the button is pushed again).


Threadstarter said its not a safety hazard if it was to shut off, so I think that would satisfy the language code.

The only reason it would shut off is a poor install such as too many blind spots.

 

[iwire]

In my area electrical rooms get toggle switches, you might be able to use a sensor to turn on the light but not turn off the light.

 

[Electric-Light]

In my area electrical rooms get toggle switches, you might be able to use a sensor to turn on the light but not turn off the light.

Would a parallel switch be legal that simply jumps the relay on occupancy sensor?
Tripped breaker and routine entry gets auto-on with 10 min off.
Toggle switch next to it on same plate marked "override" can be used for maintenance/repair when auto off is undesirable.