Occupancy Sensors in Electrical Equipment Rooms

[tkb]

Why would you waste money on the sensors and a manual switch? If they are not shutting the manual switch off now, why would you expect them to shut off the switch that over rides the occupancy sensors?

I totally agree.

Because my interpretation of the code is that there must be a "hold on" function of lightning in a room that houses Electrical equipment. We only have 8 operators , so getting everyone on board to leave the switch in "auto" shouldn't be to hard.

Turning off and on the lights = impossible

Leaving the switch alone = more likely

There's only one electrician, so in theory the only time the switch will be in "over ride" on is when I'm doing electrical work. Nobody else should have to touch it.

I'm going to try the occupancy sensors in one building to see how it goes for a couple of months before I roll it out plant wide. I'm calculating return on investment to be well under a year. Just emailed Legrand to get some install and diagram instructions. Looks fairly simple.

Just saw another technology that uses Cat-5 Ethernet cables and RJ-45 plugs in place of the low voltage wiring. That looks pretty slick!

Its just a waste of time and money. The lights will be overridden and never turned off.
If someone came into the room and the lights were overridden, and went out while they were working in the room and got hurt, OSHA wouldn't care what your interpretation of the code was. To them it says no automatic control.

 

[Abdel Rahman Mohamed]

My plant has large electrical rooms that contain low voltage switch gears and MCCs. They are unoccupied 99.5% of the time, but the florescent lights are left on 100% of the time. In my opinion this is the perfect application for occupancy sensors. We plan on leaving one light fixture on at each door so no one has to walk into a dark room.

I didnt see anything in the NEC that prohibits occupancy sensors in electrical rooms. The only safety concern I see is the lights going off while someone is working on a live circuit for troubleshooting. Troubleshooting is the only time we do hot work.

Are there any OSHA/NEC codes that prohibits occupancy sensors in Electrical Equipment Rooms?

In our project we use the occupancy sensor and we divide the whole area into 4 or 5 sections so the power saving will be more and i did not see any conflict with NEC, So you can opt the same.

 

[don_resqcapt19]

In our project we use the occupancy sensor and we divide the whole area into 4 or 5 sections so the power saving will be more and i did not see any conflict with NEC, So you can opt the same.

I don't see how that does not violate the NEC, unless you have a manual over ride function.

(D) Illumination. Illumination shall be provided for all working spaces about service equipment, switchboards, switchgear, panelboards, or motor control centers installed indoors. Control by automatic means only shall not be permitted. Additional lighting outlets shall not be required where the work space is illuminated by an adjacent light source or as permitted by 210.70(A)(1), Exception No. 1, for switched receptacles.

 

[Electric-Light]

It doesn't say shall have a means of stopping the timer indefinitely.

https://www.leviton.com/en/docs/OSSNL+Data+Sheet.pdf
1/2, 1 and 2 hrs setting and 30 sec test mode. Count down resets with each movement.

When you set it to manual on/auto off (vacancy mode), this one, like most other one shuts off after the preset time but goes into automatic on mode for 30 seconds so you can retrigger it by going into the range of view rather than going to the switch and pushing again.

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[Fulthrotl]

I don't see how that does not violate the NEC, unless you have a manual over ride function.

the word "only" means that you can't have automatic means solely controlling
the light. automatic means can be used as long as there is a manual override.
a wattstopper DW-100 is compliant.

it's to keep someone from using a 30 minute wind up timer as a switch, with
the resulting hazard when the lights go off with your hand in the panel.

a T24 compliant occ sensor will allow you to enter the room, will keep lights
on while you are on the room, and turn them off when you leave. the built
in override will allow local control, and let you turn off or on the light as you
see fit. it will then stay in forced mode until you leave, whereupon it will reset.



Control by automatic means only shall not be permitted.

 

[gadfly56]

the word "only" means that you can't have automatic means solely controlling
the light. automatic means can be used as long as there is a manual override.
a wattstopper DW-100 is compliant.

it's to keep someone from using a 30 minute wind up timer as a switch, with
the resulting hazard when the lights go off with your hand in the panel.

a T24 compliant occ sensor will allow you to enter the room, will keep lights
on while you are on the room, and turn them off when you leave. the built
in override will allow local control, and let you turn off or on the light as you
see fit. it will then stay in forced mode until you leave, whereupon it will reset.



Control by automatic means only shall not be permitted.

I did not understand that part when you first suggested this solution. How long does the forced mode stay on, and what will tell it "time to go to occ sensor mode"?

 

[don_resqcapt19]

It doesn't say shall have a means of stopping the timer indefinitely.

https://www.leviton.com/en/docs/OSSNL+Data+Sheet.pdf
1/2, 1 and 2 hrs setting and 30 sec test mode. Count down resets with each movement.

When you set it to manual on/auto off (vacancy mode), this one, like most other one shuts off after the preset time but goes into automatic on mode for 30 seconds so you can retrigger it by going into the range of view rather than going to the switch and pushing again.

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If you don't have to physically turn it back to auto when you leave the room, it will get a red tag from me.

 

[GoldDigger]

It is hard to distinguish between failing to notice that you are still in the room and turning out the light and failing to notice that you are in the room and going back to automatic and then turning off the light!

Sent from my XT1585 using Tapatalk

 

[Fulthrotl]

I did not understand that part when you first suggested this solution. How long does the forced mode stay on, and what will tell it "time to go to occ sensor mode"?

depends on the control... anywhere from 5 minutes to 4 hours.

it'll go to occ sensor mode when there has been no input in the
room for whatever time you set it for. it keeps resetting the
override as long as you are in the room.

if you go to something like an nLight control, you can pretty much
make it sing and dance, and blink twice to let you know time's up.

in calif. you need an occupancy sensor in a utility room. no T24
cert until you put one in. per T24, there also must be local control
of that light available.

that fits in with accommodating the "only" restriction in the NEC.
the NEC doesn't want a light that isn't controllable locally in a room
where there is a safety situation resulting from automation.

lutron uses standalone switches that you can pair with a ceiling
mounted occ sensor, or multiple sensors, to provide full coverage
if there is a concern that you can't adequately monitor a larger or
irregularly shaped area.

 

[Abdel Rahman Mohamed]

If you're working in a corner with no line of sight to the sensor, which is usually mounted by the entrance, it's going to get dark sooner or later unless the "on" time can be set for long enough, say 2 hours, to guarantee you'll be going near it, if only for a bathroom break.

In our project we use well distributed PIR to cover all areas along with overwrite switch and both together can do the job well.

 

[don_resqcapt19]

In our project we use well distributed PIR to cover all areas along with overwrite switch and both together can do the job well.

As long as the over ride is 100% manual, I would be fine with that, however an over ride that automatically returns the lighting control to the sensor would get a red tag from me.

 

[GoldDigger]

As long as the over ride is 100% manual, I would be fine with that, however an over ride that automatically returns the lighting control to the sensor would get a red tag from me.

So a spring wound timer would not be acceptable, unless it had an always on detent position.

 

[don_resqcapt19]

So a spring wound timer would not be acceptable, unless it had an always on detent position.

Without the always on, it would get a red tag from me.

 

[mtfallsmikey]

Personally, I wouldn't do it, as well as in a mech. room.

 

[victor.cherkashi]

I personally don't show sensors on drawings in mechanical and electrical rooms, in energy code I use exemption "sensor is not required where it can endanger safety of occupant"

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[sameguy]

Auto with key switch override.
I would rather see more outlets for plugging in test equipment and aux lighting, change to led fixtures.