Spacing between lights and ceiling

[hemismith]

After a year of talking about it we're finally going to install some permanent lights at my church. One question I have is how much distance does there need to be between the light (for example a 500W PAR 64) and the ceiling. I tried to access the NEC on the NFPA web site and it appears you can only jump to chapters and then have to page 1 at a time to get to the appropriate section (such as 520). Is there any more convenient online code? I'm not even sure if this spec is in there anywhere.

Thanks.

(Note: I'm not doing the work, but I want to know the answer in case the contractor doesn't.)

MOD NOTE: Posts from threads titled Do I need to protect these lights? and Hanging lighting pipe , since they all concern the same project, have been moved into this thread. Some confusion will likely ensue.

 

[Les]

What type of ceiling?

I've seen lights pretty close to grid ceilings in cafetoriums, etc. Usually they were hung from a rigid pipe about 4" below the ceiling.

Then you've got ballrooms with Unistrut and the like -- it appears as though you can get them right up to the ceiling.

 

[hemismith]

Good question. Above the stage I think it's standard drywall and wood. Above the main hall I think it's acoustic tile over plywood but I'll have to double check.

 

[porkchop]

You'll probably have to some kind of building engineer, but more than likely you're going to have to look and the max external temperature of the fixtures you are looking at purchasing. It's usually published on the manufactures website. For a source 4 lamped at 750W it's 217°C (423°F). Then you'll have to talk to someone that knows a lot more about building materials than I do (a building engineer or maybe a consulting company) and they should be able to tell you mandatory clearances.

 

[hemismith]

OK, thanks. I hadn't seen temp specs but will see what I can find. And yes, I'm thinking now that I need to bring in a specialist. I had actually called the two main stage lighting places here and requested someone come out to give me an estimate but neither called back.

 

[JD]

More of a fire code issue than an electrical code issue. I would contact your local fire marshal. The bigger issue is to make sure that the cans cannot be accidentally pointed into the ceiling. The beam is the biggest fire issue.

 

[tjrobb]

Indeed, on another thread I mentioned how I've seen a Source Four burn through a 2x4. All the way through...

 

[hemismith]

Wow! That's amazing. Thanks.

Yes, I guess this is a fire code issue, but the electrical code is put out by the National Fire Protection Association so I figured it might be included there. But I looked in the fire code itself and there is a section on studios and stages but it doesn't say much. It refers to the electrical code and to the UL code. So I looked at the referenced UL code and it essentially said that manufacturers should put warning labels on the fixtures regarding installation restrictions. I looked at online manuals for a couple fixtures and didn't see any installation guidelines though.

 

[JD]

Yes, I guess this is a fire code issue, but the electrical code is put out by the National Fire Protection Association so I figured it might be included there.

That is because many electrical issues can quickly become fire issues

Fire marshal is the one to go to. He/She may or may not be a lot of help, but if something ever went wrong, that is the person who would be assessing the cause/blame. It's nice to know they approved or recommended a specific action.

 

[hemismith]

Good points, I'll do that, thanks everyone.

 

[hemismith]

Do I need to protect these lights?

Sorry to bother you all again. Attached is a picture of one of the places I want to mount the lights I mentioned in a previous post. We would be removing the track lighting and hanging a pipe on which to mount "real" lights. My plan was to just take them down after each show. Or maybe build some kind of protective screen around them. But some lights are pretty durable and I'm wondering if it would be possible to just leave them up. The track lights have gotten knocked around occasionally but never broken, and we haven't had an issue with the house lights. The biggest risk is from errant volleyballs. I think they are about 24 feet up. What do you think?

 

[shiben]

Re: Do I need to protect these lights?

Sorry to bother you all again. Attached is a picture of one of the places I want to mount the lights I mentioned in a previous post. We would be removing the track lighting and hanging a pipe on which to mount "real" lights. My plan was to just take them down after each show. Or maybe build some kind of protective screen around them. But some lights are pretty durable and I'm wondering if it would be possible to just leave them up. The track lights have gotten knocked around occasionally but never broken, and we haven't had an issue with the house lights. The biggest risk is from errant volleyballs. I think they are about 24 feet up. What do you think?

They should probably be protected, just to make sure you dont have a lamp out with 20 minutes till doors or something like that.

I would d

 

[derekleffew]

Re: Do I need to protect these lights?

...Or maybe build some kind of protective screen around them. ...

Theatrical luminaires have many more parts susceptible to being hit than track lighting fixtures. See Spotlight Cage.pdf by SSRC.

BTW, you don't have to remove the track. See

http://www.1000bulbs.com/product/4305/NORA-NT327W.html
You DO need to know the brand/model of the track however. Check with a lighting distributor.

 

[BanditRO]

Re: Do I need to protect these lights?

Sorry to bother you all again. Attached is a picture of one of the places I want to mount the lights I mentioned in a previous post. We would be removing the track lighting and hanging a pipe on which to mount "real" lights. My plan was to just take them down after each show. Or maybe build some kind of protective screen around them. But some lights are pretty durable and I'm wondering if it would be possible to just leave them up. The track lights have gotten knocked around occasionally but never broken, and we haven't had an issue with the house lights. The biggest risk is from errant volleyballs. I think they are about 24 feet up. What do you think?

I believe SSRC, and probably others, offer cages for just this application.

 

[Footer]

Re: Do I need to protect these lights?

When Apollo first released the right arm, they had a cage for it as well. Get the cage put in, your fixtures will thank you. I know when I was 11 years old we used to drop kick just about any ball we could get our hands on at any target we could find....

 

[shiben]

Re: Do I need to protect these lights?

You could build your own if your a bit handy with a welder. Does not look too complicated.

 

[hemismith]

Re: Do I need to protect these lights?

Thanks everyone! Great suggestions!

 

[hemismith]

Re: Do I need to protect these lights?

I know when I was 11 years old we used to drop kick just about any ball we could get our hands on at any target we could find....

Always good to learn from history!

 

[hemismith]

FYI I talked to one of the local theater lighting companies today about doing the work and they said the lights need to be 18 inches from the ceiling. But I will clear it with the marshal.

 

[hemismith]

Hanging lighting pipe

Please excuse my ignorance .... the lighting specialist I talked to today said they hang light pipe with chains. How would you get enough stability to be able to adjust and work on them, use 2 chains in a V shape? I realize trusses are hung with chains, but is there a reason not to use a rigid attachment? (Do I need to post this in the rigging forum? I'm looking at it from a functional perspective, not a structural one.)