Old style Tit Out twist "legal"

[SteveB]

I'm aware that the old style "tit out" twist lock connectors have been not rated, for decades now, for 120v, 1 pole, 3 wire (hot, neutral and ground) use.

So I have a black box theater full of these receptacles, 60 dimmers worth and probably 120 or more receptacles, all in 5 - 4x4 raceways, ceiling flush mount with flush receptacles, plus some side wall boxes.

The ceiling of the theater this stuff is mounted to is now known to be asbestos tile, and it's all coming down and out, raceways and all. The wiring and raceways are easily +40 years old, I think the wiring is all original THHN, or whatever was used in the 1970's.

I have argued that it's likely illegal (and makes no sense) to restore these raceways to their old location, after the abatement. Not sure the "illegal" issue will wash and not certain of the code on this.

FWIW, in 2010 we actually purchased 6 ETC raceways as replacement, 2P&G receptacles and all, then the college pulled the plug on install. We stored the raceways away and now the moment has come, we hope, but I'd like to be sure about the old twist crap.

Seems like a no brainer, but it's the State of NY, land of no-brainers.

 

[ship]

You are certainly a authority to be listened to on the recommendation.. History, a 80's to 70's reversal of the stage pin to twist is normal, so a photo of the non-NEMA plug would be a further understanding of what they chose and why. THHN or THWN the older version is fine and not persy antiquated assuming as probably the case 12ga.


Asbestos abatement I hope does so also with the catwalk and in general. Great job - slap on the back in getting it done.


I'm not certain about your plug, could be a plug that is not polarized which would be a reason not to re-install if any help.

 

[JD]

If the raceways are coming down, I can think of no reason on earth not to have the 2P&G raceways go up in their place!
The code issue is a good question. ST can correct me if I am wrong, but if they were in use (grandfather) it would not be an issue, but by pulling them and having them put back in, it becomes a "new" install and that may be a violation.

 

[Malabaristo]

The non-NEMA twistlocks that are existing are almost certainly not UL listed, so there is a pretty good argument that they shouldn't be reinstalled. It's mostly just a question of whether the AHJ (electrical inspector or whatever applies here) decides you're doing enough work that it all has to be brought up to current code.

I'd have to do some digging to find it again, but I do know there are new versions of that connector available that actually are UL listed... from Cooper maybe? Theoretically you could install new raceways with the new, UL listed connectors and be fine. But if you already have new ETC raceways, then using those would make a whole lot more sense.

 

[SteveB]

If the raceways are coming down, I can think of no reason on earth not to have the 2P&G raceways go up in their place!
The code issue is a good question. ST can correct me if I am wrong, but if they were in use (grandfather) it would not be an issue, but by pulling them and having them put back in, it becomes a "new" install and that may be a violation.

Well. that's my thought as well. And no point in putting back old stuff when new is available. They would need to pull out most of the old wiring as well as the raceways that home run to the booth will be removed and I cannot see them doing anything except install new THHN right back to the dimmers. Thus the case for the new install should be easy, but it is CUNY......

 

[venuetech]

Is there not a lot more labor involved in reusing these aged devices? If the boxes were attached to the asbestos tiles do they not need to now be properly cleaned?

 

[SteveB]

Is there not a lot more labor involved in reusing these aged devices? If the boxes were attached to the asbestos tiles do they not need to now be properly cleaned?

Well, yup there's that as well.

It's always helpful to have an ironclad reason, such as non-compliant receptacles period. Thus the OP.

My 36 years at this facility has left me jaded and cynical as to how they always seem to proceed in the least logical manner and make the absolutely wrong choices.

 

[Van]

I agree with venuetech on this there is probably more cost associated with installing new L5-20 receptacles and updating the internal wiring, not to mention you'd need a UL listed shop to do the work, unless I'm mistaken. Is PBG still acceptable in theatrical installations?

 

[SteveB]

I agree with venuetech on this there is probably more cost associated with installing new L5-20 receptacles and updating the internal wiring, not to mention you'd need a UL listed shop to do the work, unless I'm mistaken. Is PBG still acceptable in theatrical installations?

"PBG" ? Never heard that term.

The rub on this is the system currently has 5 raceways and 4 wall boxes with twist (connected to 60 Sensor dimmers that stay), being removed, with 6 raceways and 14 wall boxes being installed and now a 120 dimmer system (as a filled up Sensor 96 plus a re-purposed Unison/Sensor 24) being installed. Plus a small DMX patch bay with associated LoVo wiring, all needing installation.

In addition to this is that the current "rigging" is mostly a grid of channel steel loosely "installed" onto a plaster/wire mesh & lathing ceiling. Thus that all will come out and we recommended a 1-1/2" OD 4x4 pipe grid mounted directly to the concrete slab and beams above the current hung ceiling. With acoustical treatment of the underside of the concrete as that's the orchestra seating floor of the 2300 seat theater above.

I am walking a fine edge of recommending a system that's an expansion of existing, plus the pipe grid isn't going to be cheap.

Our attitude is 1) We could have told "them" all this a year or so ago if they had consulted with us as to their plans to remove the ceiling, so sorry if it's all now a surprise, 2) They really have no choices. They will remove the ceiling and they cannot put back the channel steel mounted as it is currently. They need to bring it up to code. 3) The electrical cannot go back either and our 120 dimmer expansions is the cheapest solution as the $50,000 in materials are already purchased.

 

[STEVETERRY]

The non-NEMA twistlocks that are existing are almost certainly not UL listed, so there is a pretty good argument that they shouldn't be reinstalled. It's mostly just a question of whether the AHJ (electrical inspector or whatever applies here) decides you're doing enough work that it all has to be brought up to current code.

I'd have to do some digging to find it again, but I do know there are new versions of that connector available that actually are UL listed... from Cooper maybe? Theoretically you could install new raceways with the new, UL listed connectors and be fine. But if you already have new ETC raceways, then using those would make a whole lot more sense.

And there you have it....these connectors are not UL listed, nor can they ever be---because they do not have a designated grounded conductor (neutral) contact. The contact is connected to an ungrounded (phase) conductor when operating at 208V, and to a grounded conductor (neutral) when operating at 120V. UL will no longer accept this.

Bottom line: replace the connectors with a NEMA type or with ANSI/ESTA E1.24 stage pin connectors.

ST

 

[SteveB]

And there you have it....these connectors are not UL listed, nor can they ever be---because they do not have a designated grounded conductor (neutral) contact. The contact is connected to an ungrounded (phase) conductor when operating at 208V, and to a grounded conductor (neutral) when operating at 120V. UL will no longer accept this.

Bottom line: replace the connectors with a NEMA type or with ANSI/ESTA E1.24 stage pin connectors.

ST

Thx Steve.

 

[Ron Foley]

Are you doing this work internally or bringing in an electrician?

if you are doing the work your self, contact the local inspector and get their approval to re install prior to doing the work.
(suggesting that you can do that work yourself in your location)


if you are bringing in an electrician, then the inspection and ticket ends up in their court
(ask their opinion) I am sure they will quickly tell you NO.

with that said, re installing a raceway with the old style plugs would not fly in our province and most likely anywhere in Canada

once it has been pulled out of service , it is done



we have been thru this many times for the last 30 years

Listen to the folk that have previously replied (REPLACE THEM)

 

[SteveB]

We are not doing any work in house. The building is getting a general renovation, so this will now be part of it. I don’t think they’ve figured out the specifics and financing yet, I expect it’ll be change orders to the contractors, funded from contingency monies.

I should note that we have all the required hardware, it’s all raceways and boxes from ETC, 2P&G and Edison for utility. All up to code, all easy to install.

 

[teqniqal]

In addition to this is that the current "rigging" is mostly a grid of channel steel loosely "installed" onto a plaster/wire mesh & lathing ceiling. Thus that all will come out and we recommended a 1-1/2" OD 4x4 pipe grid mounted directly to the concrete slab and beams above the current hung ceiling.

You wrote 1-1/2" O.D.

Did you possibly mean 1-1/2" I.D. (1.9" O.D.)? This would be much more 'standard' for theatrical use. This is an easy thing to mis-speak in a conversation or letter to the powers that be, and can have a big impact on budget and functionality. Be sure to have a structural engineer review this, too, as the over-all weight of a 4'x4' steel pipe grid with the live load (fixtures & curtains) and static load (raceways & curtain track) can be enormous. Because this is an existing building, it may be necessary to use a wider spacing (6'-8') for the grid pipes and/or go to aluminum pipe.

As an aside, I once had a project where the fire sprinkler contractor convinced the general contractor that they could do the black box theatre pipe grid, and without asking the Architect or Consultant, just did it. It cost the G.C. twice as much as hiring a theatrical contractor (rigger), and they pretty much installed an unusable grid, despite the explicit drawings in the project set. Such a simple things screwed-up so thoroughly (sigh).

 

[SteveB]

You wrote 1-1/2" O.D.

Did you possibly mean 1-1/2" I.D. (1.9" O.D.)? This would be much more 'standard' for theatrical use. This is an easy thing to mis-speak in a conversation or letter to the powers that be, and can have a big impact on budget and functionality. Be sure to have a structural engineer review this, too, as the over-all weight of a 4'x4' steel pipe grid with the live load (fixtures & curtains) and static load (raceways & curtain track) can be enormous. Because this is an existing building, it may be necessary to use a wider spacing (6'-8') for the grid pipes and/or go to aluminum pipe.

.

Probably correct on the pipe and I'm not doing the spec's. Ridgid aluminum is a good idea if weights an issue, but in truth and this applies to the spacing and layout, we have never seen the underside of the concrete slab, thus have no idea as to beam placement, attachment points, etc... that indeed will be the architect and engineer to determine.

 

[Blacksheep0317]

Generally in NYS anything that changes 20% or more of the existing construction of a permitted project means that you loose "grandfather" stance in terms of codes. (bought a foreclosure with no Certificate of Occupancy yet...I've become good "friends" with my local code officer). The hard part, is this is a very general statement. 20% of structural components? 20% of gross materials? Only your local CO can tell you for sure, but chances are non bueno.

If nothing else I would fight tooth and the nail simple fact that putting 30+ year old gear in with a brand new system will end up doing nothing but costing more money in the long term with man hours of maintenance, adapting anything outside of house stock to work with your infrastructure, and you will still end up making the change eventually anyways more than likely.

 

[SteveB]

Generally in NYS anything that changes 20% or more of the existing construction of a permitted project means that you loose "grandfather" stance in terms of codes. (bought a foreclosure with no Certificate of Occupancy yet...I've become good "friends" with my local code officer). The hard part, is this is a very general statement. 20% of structural components? 20% of gross materials? Only your local CO can tell you for sure, but chances are non bueno.

If nothing else I would fight tooth and the nail simple fact that putting 30+ year old gear in with a brand new system will end up doing nothing but costing more money in the long term with man hours of maintenance, adapting anything outside of house stock to work with your infrastructure, and you will still end up making the change eventually anyways more than likely.

The abatement project, mentioned early, is to tear out the known asbestos and open up the infrastructure to determine how bad the damage. The "real" project is replacing exterior concrete ramps alongside the orchestra seating area that are also the roof to the basement below. These ramps have leaked for all the 36 years I've been at Brooklyn, no exaggeration. Thus they have ( I sincerely hope) extra contingency funding in place to deal with things they cannot for see, like a theater pipe grid.

 

[Lyle Williams]

They will need to find the funding. Advance notice of the expected costs and scheduling impacts are what is needed.

 

[SteveB]

They will need to find the funding. Advance notice of the expected costs and scheduling impacts are what is needed.

We actually had all the required plans drawn up as to raceway and wall box placement, wiring numbers and lengths, etc... so all we needed to add was the desired 4x4 pipe grid design. If they choose to scale back to just SL/SR pipes to hang only the raceways,and make it strong enough to add US/DS pipes after, we will deal with that. They likely have 6 mos. or more to take what we are requesting and turn it into reality. The project bids came in high initially and the City University had to find supplemental funds to get the job done, not my problem really.

 

[Van]

"PBG" ? Never heard that term...

Perhaps it's a West coast thing? Parallel Blades with Ground "PBG." Certainly easier than saying 2P&G. Hell, I grew up simply calling them "Edison's".