An interesting electrical conundrum

[ScaredOfHeightsLD]

So, without attacking the nature of this post. Let me preface by saying that this is strictly informational and I am looking for the best way to procede with the administration at this local high school.

I was brought in as a designer/tech for a local band gala and during the install last night, I noticed two circuits on the raceway where a stage pin connector had welded itself to its receptacle. After breakering off the main, I opened the raceway to remove the female port, hoping to replace it with a new one when I noticed that there was no grounding wire run through it. Since this is a relatively new install (I believe within 10 years) this seemed off to me. The question I have, before I frighten the school administration, is can you think of any reason or loophole within the NEC code that would allow an installer to not run a grounding wire to a receptacle on a raceway?

I want to bring this to the attention of the right people, but I also want to make sure that I have all my ducks in a row before doing so. Thanks!

-Mike

 

[JD]

The only possible loophole would be it the full raceway was a pre-assembled product that carried it's own certification as an "engineered assembly." (Much the same holds true for Soco cables.) Are the receptacle grounds tied to the case? (Just wondering.)

In any case, I have to agree that I would not be comfortable with that design, but it may very well squeak into compliance on the above loophole.

I am sure others will chime in with other opinions, so I would let this thread brew for a day or so.

 

[MPowers]

Check and see if the wiring of that receptacle is the same as others or if it is possible that it is a single wiring error. Although I don't know if case bonding would be code complient, I suppose it is possible. Check and see if the receptacle grounds are directly bonded to the case by contact or the mounting screws. Who is the raceway manufacturer?

 

[phenry]

I would venture a guess and say that the receptacle grounds itself to the raceway, which would then have a ground lug probably near where it is being fed. Bare metal to metal contact between the strip and the receptacle would be a pretty good sign that this is the case, but when in doubt, ohm it out. Make sure you have a ground or there is a problem that you should definitely bring up to the powers that be.

 

[gafftapegreenia]

From Rosco's Website:

"Panel Mounts

The Connector is simply inserted in the panel opening and 2 set screws are tightened.

20, 60, and 100 Amp Panel Mount Connectors and Receptacles. The first self grounding connector of its kind to be UL Listed. The unique self grounding locking springs means no need for installing a ground wire, simply install the connector and you are done."

Connectors - rosco.com

Now, did this install use Rosco products? I have no idea. Are there other products on the market like this? Again, I must confess my ignorance.

 

[DavidNorth]

Now, did this install use Rosco products? I have no idea. Are there other products on the market like this? Again, I must confess my ignorance.

Bates and Union Connector 20A females are also self-grounding. It is quite common to construct circuit distribution products using the built-in grounding feature and has been for well over a decade [IIRC, it's been almost two decades]. Of course the NRTL file needs to call this out as an acceptable build practice and one needs tight control over sheet metal hole sizes to work correctly.

David