Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[Milt Hathaway]

$90 million dollar performing arts center, built in 2011, part of one of the top state universities in the country. Their inspector not only signed off on this, he argues that this is perfectly safe and legal because all of the hardware is UL listed.

Yes, those are male outlets. Yes, they are 3 phase with no neutral. These (there are three) are supposed to be shore power.

The building management threw together a "temporary" freestanding power panel right after the venue opened, and fed that panel with 300' of 5-wire 0000 running across the loading dock fed from one of the on-stage 400A panels.

The university still refuses to do anything about it. Building management was smart enough to kill the breakers, although I can't confirm that they are actually locked out. Management would have just replaced the connections on their own, but no neutral was pulled during construction and an easy solution hasn't yet been found. Plus, the architect designed them to be installed over 100' from the bus parking.

[Mike Sokol]

Yes, those are male outlets. Yes, they are 3 phase with no neutral. These (there are three) are supposed to be shore power.

Is there a 4th wire EGC (ground) in this run? If so, you could use two of the legs to wire a "single-phase" 120-208 female receptacle. Yes, it won't run lift motors, but it would be good for PA or lights. I don't know in what universe this inspector thinks that just because something is UL listed that you can use it in violation of the NEC. Can you call in a stage inspector and get these receptacles tagged and officially taken out of service until they're "repaired" and meet code? I would also drop a letter with a picture to the legal representative of the center, warning of the potential lawsuit if someone gets killed from something that's obviously in violation of code.

Plus, the architect designed them to be installed over 100' from the bus parking.

If these are supposed to be shore power for tour bus parking, they traditionally install a 120-240/50-amp NEMA 14-50 FEMALE receptacle located in a waterproof pedestal. Of course, the shore power plug for the bus is male. The latest code allows for 2 legs of 3-phase wiring with 120/208-volts for campgrounds. See http://www.noshockzone.org/rv-electrical-safety-part-iii-%E2%80%93-outlets/ for an primer on this.

[Milt Hathaway]

Oh, I know that they are supposed to be. Just posted to remind people that even the inspectors charged with assuring our safety don't always know what they are doing.

[Mike Sokol]

Oh, I know that they are supposed to be. Just posted to remind people that even the inspectors charged with assuring our safety don't always know what they are doing.

Milt, yes I know that you know. And you know that I know that you know....

But I try to post these extra details for those who DON'T know. So, are there only 3 wires running to each Male "outlet" or is there a 4th EGC ground wire? If so, my recommendation of rewiring as 2-phase 208V on NEMA 14-50 receptacles is still valid. 

[Tim McCulloch]

Milt, yes I know that you know. And you know that I know that you know....

But I try to post these extra details for those who DON'T know. So, are there only 3 wires running to each Male "outlet" or is there a 4th EGC ground wire? If so, my recommendation of rewiring as 2-phase 208V on NEMA 14-50 receptacles is still valid.

And if not this whole mess should be condemned and removed.  This is an electrocution waiting to happen no matter if it's locked out today or tagged out tomorrow.  Eventually the lock will get cut off or tag disregarded when nobody can find the key and the tag is now illegible - at some point in the future this will be energized.

[Stephen Swaffer]

Out of curiosity, what is the NEMA designation of these inlets?  They are an appropriate inlet to supply power to a building/panel so UL listing is typical-but listed for what is the question and still must be applied/wired correctly.

It looks to me like this connection is designed to ground through the shell-hopefully the answer to Mike's question is yes there is a 4th wire.  Not cheap, but perhaps the best solution to have maximum capacity would be a delta-Y isolation transformer to create a "derived" source with a neutral-you would need a small panel or at least a 3 pole breaker after the transformer, but it would allow the largest possible capacity at this location without running/pulling new wire.  Then install the correct outlets!

[Jeff Bankston]

Just posted to remind people that even the inspectors charged with assuring our safety don't always know what they are doing.

you got that right. i'm a commercial electrician and have gotten into arguments with several inspectors because they didnt have a clue as to what they were doing and i had to show them in the code book that my job was done according to code. i have seen some things that were signed off that were not to code and dangerous. here in los angeles old union electricians get hired to do inspections and i'm willing to bet some never made it past helper status.

[ProSoundWeb Community]