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#110436 - 04/10/06 07:52 PM An Emergency Panel  
electure  Offline

Joined: Dec 2000
Posts: 4,262
Fullerton, CA USA
This panelboard powers the lighting in the stairs and corridors, the exit fixtures, etc in a 9 story residential building.

In an outage, the 480V generator will power this panel through a little 30 KVA transformer.

And then..............?

[Linked Image]

[Linked Image]

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#110437 - 04/10/06 08:05 PM Re: An Emergency Panel  
Trumpy  Offline

Joined: Jul 2002
Posts: 8,223
SI,New Zealand
Well Scott,
That transformer will work.... for a short time at least.
How could a thing like this happen?.
One other thing, I have certain mis-givings about that run of EMT over the top of that exhaust silencer as well, we all know how hot they get!. [Linked Image]

#110438 - 04/11/06 11:55 PM Re: An Emergency Panel  
mhulbert  Offline
Joined: Oct 2004
Posts: 132
Anaheim, CA USA
What exactly is wrong here...I thought the panel was not fed, but on closer look it seems there is a feeder coming in the bottom of what looks like a feed trhough panel.

Am I missing something stupidly obvious?


#110439 - 04/12/06 06:44 AM Re: An Emergency Panel  
George Corron  Offline
Joined: May 2001
Posts: 717
Lorton, Va USA
Agreed, more info is needed here. Many of those 'silencers' (they're not called mufflers for a reason) are wrapped inside with fire and heat retardent. That means it may not get as hot as you'd think, but that should be in the submittal documents. It also appears that it was here for some time prior to the EMT, so who's problem is that?

I'd be more concerned with the "air over" portion of the cooling. That's something that will get overlooked over the years.

#110440 - 04/12/06 07:06 AM Re: An Emergency Panel  
IanR  Offline
Joined: Dec 2004
Posts: 328
Palm Bay FL USA
"the 480V generator will power this panel through a little 30 KVA transformer.

And then..............?"

While a 30KVA transformer looks a little undersized for the generator. (I am guessing by the 6cyl diesel that it is 60KW or more)
If it has a correctly sized OCD it should be fine electrically. No doubt the diesel will wet stackfrom being underloaded, but that is another story. Outside of the EMT over the exhaust, I don't see too much problem.
Well, I don't see any fire suppression system either, but that could just be outside of the photo.

#110441 - 04/12/06 08:14 AM Re: An Emergency Panel  
n1ist  Offline
Joined: Feb 2002
Posts: 183
Malden MA
30KVA for 9 stories is about 3KVA/floor. Depending on the size of each floor and types of fixtures on emergency power, that may be enough.

#110442 - 04/12/06 12:54 PM Re: An Emergency Panel  
T-Kat  Offline
Junior Member
Joined: Dec 2004
Posts: 3
Morristown,Tenn. USA
Since this is a lighting and appliance panel,408.36(D) requires overcurrent protection on the secondary side of the transformer. I don't see a main breaker or any other OCP device in the picture.

#110443 - 04/13/06 05:07 AM Re: An Emergency Panel  
techie  Offline
Joined: May 2005
Posts: 246
palo alto, ca usa
I would assume that the generator is powering more than just lighting, otherwise why would it be a 480v genset?

#110444 - 04/13/06 07:37 AM Re: An Emergency Panel  
electure  Offline

Joined: Dec 2000
Posts: 4,262
Fullerton, CA USA
Sorry it took me so long to get back to this.

The 30 KVA is plenty to supply the loads that are fed here. My big concern is with the 1" EMT run right above the silencer.

This is not the original panel that was installed, it was installed, I believe, after this one about 10' away burnt out, . (And probably without a permit or inspection)

[Linked Image]

There's lots of heat coming off of that exhaust system. This has happened just during weekly tests of about 15 minutes.

[Linked Image]

Also, the panel is mounted right under the silencer's drain plug.

The 480V genset does supply other loads, but has enough capacity to handle them.

#110445 - 05/02/06 06:09 PM Re: An Emergency Panel  
Gus99  Offline
Joined: Aug 2005
Posts: 24
Los Angeles, CA
9 story building? 480v generator?

Can you say "elevator machinery"

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