TENT TEMPORARY LIGHTING

[jap]

On a tent is it required to bond all of the poles and cables together when installing temporary lighting in them?

The tempoarary tents are 20x20 and have 4 aluminum pipe legs (1 in each corner) and 4 aluminum pipe runners that run horizontally between the 4 legs at a height of 10'.

The 4 corners are tied together by a 1/2" cable that runs diagonally from corner to corner and the 2 cables cross in the middle of the tent at a height of 10'

There is an 8' center post that is in the middle of the tent. The base of the center post rests where the 2 cables cross an the top of the center post supports the peak of the tent.

The bottom of the center post has a nylon cross hatch that sets over the 2 cables to keep it from moving one way or the other.

My question is would you have to bond all of the individual items together to insure a quick return fault path should the temporary lighting wiring happen to rub into the cable or posts?

The temp lts are on romex pierced through the hot and neutral , the ground is not terminated anywhere on the tent posts and even if it was, without bonding each and every joint there is no way of insuring a solid return path.

Is there a requirement for gfi protected wiring for tempoarary lighting in this instance?

 

[iwire]

No there is no requirement to bond anything that is not 'likely to become energized'.

That said ........ If this tent will be accessed by the general public I would stay away from NM and use rubber cords. Also keep in mind all splices have to be in boxes.

The only place you can have open splices in temps are construction sites.

 

[jap]

Do the boxes need to be weatherproof for temporaries?

I've also seen temp quarts lights in tres with standard 4/0 boxes with blank covers.

 

[zbang]

From my experience doing tents:

All 120v circuits in public tents are on GFCIs. (Almost all of the rest are, too.)

We don't bond the tent structure to itself or anything else. (Large portable stages usually get a rod, though. I don't think it does much, but the sound company often wants it.)

Weatherproof boxes? For receptacles, yes.

No way no how would I use romex & piercing connections into a tent. It's all hard service cord with standard plugs/caps. See Art. 590.

For a 20x20 tent, I would probably hang a 300w worklight from the cross-wires and aim it up at the top. At $10 each, it beats hand-building something. Sometimes, the same light will go up the center pole. We have not had any problems with heat on the tent top. Since most of our tents are larger, they often get complete 10-socket temporary light strings.

A couple of examples are attached.

 

[yanici]

The enclosed tents, at events where I used to work, also had exit signs and emerg. lighting near the exits.

 

[iwire]

A couple of months ago we did a big event in about seven large tents, provided over 125 - 20 amp 120 volt circuits all GFCI protected all rubber cords. Two generators on site for power. For the two day show it was almost 25K just for temp power.

 

[CDAEF2002]

BONDING

BONDING

NEC 525.30 SAYS BONDING REQUIRED FOR METAL PARTS OF PORTABLE STUCTURES THAT SUPPORT ELECTRICAL EQUIPEMENT

 

[jap]

I use rubber cord and 150w HPS Dusk to dawns strut strapped to the center pole with a shorting cap.

But Ive seen romex and piercing connectors. (Which I dont use).

Either way I was wondering if the lighting was required to be GFI'd.

 

[renosteinke]

CDAEF, that's a very nice citation- and welcome to the forum.

525.30 also mentions 'likely to become energized,' and says that the equipment grounding conductor can serve as the bond.

Would this not mean that as long as the the circuit has a ground wire, and that any fixtures or appliances are either bonded internally or double-insulated, that there is no need to do any more bonding? That simply hanging a trouble light from a tent frame does not require you to put little copper jumpers everywhere?

 

[iwire]

From the 2008

IV. Grounding and Bonding
525.30 Equipment Bonding. The following equipment
connected to the same source shall be bonded:

(1) Metal raceways and metal-sheathed cable

(2) Metal enclosures of electrical equipment

(3) Metal frames and metal parts of portable structures,
trailers, trucks, or other equipment that contain or support
electrical equipment

The equipment grounding conductor of the circuit supplying
the equipment in items (1), (2) or (3) that is likely to
energize the metal frame or part shall be permitted to serve
as the bonding means.

 

[jap]

Like the center post that has the "Nylon" bottom on it that sits on the cross cables.

If the fixture shorted out, yes it would trip the breaker since the Fixture is strapped and bonded to the center post.

But if the cord rubbed into the cable below the center post, what would trip the breaker?

The cable is not bonded to the centerpost because of the nylon barrier.

 

[zbang]

If the fixture shorted out, yes it would trip the breaker since the Fixture is strapped and bonded to the center post.

But the fixture's case is already bonded or non-conductive, assuming that it's a listed assembly. Not a problem here.

But if the cord rubbed into the cable below the center post, what would trip the breaker?.

With that concept, you'd have to bond everything. I generally interpret "likely to become energized" to mean things directly enclosing terminations or physically connected to the same. For instance, the metal outlet box. The pipe that some SOOW is strapped to is not likely to become energized.


FWIW, the 2005 handbook tells us (pg 224):
Unlike the metal piping systems covered in 250.104(A), this requirement applies only to metal piping systems that are likely to become energized. What this means is that where metal piping systems and electrical circuits interface through mechanical and electrical connections within equipment, a failure of electrical insulation can result in the connected piping system(s) becoming energized.
[...]
Typically, the use of an additional bonding jumper is not necessary to comply with this requirement because the equipment grounding connection to the non?current-carrying metal parts of the appliance also provides a bonding connection to the metal piping

 

[jap]

Another explanation by the handbook saving the day.

Thanks,
JAP

 

[jap]

the only problem is that the nylon bottom on the center post does not provide a bonding connection to the rest of the piping on the tent.

 

[jap]

But I guess the center post that the fixture is bonded to,,,,not the cord ziptyed to the cable below,,,, is whats most "Likely to become energized".

Is that the concept?