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Exit sign and electical outlet #113612 08/10/02 03:07 PM
Joined: Oct 2000
Posts: 3,630
Admin Offline OP
Here's two fuzzy pictures of one of many nightmares I found in a building our company bought a short while ago.

[Linked Image]

I discovered the problem when I plugged a drill into this outlet and the drill quietly hummed as the exit light went out.

[Linked Image]

This is a 277V exit sign. The electrical outlet is being powered by the tiny 277/120 transformer that normally powers the two 15W lightbulbs.

Actually this could be a "how many violations can you name" quiz. Feel free to use these pics,

- Ryan Cruzan

Tools for Electricians:
Re: Exit sign and electical outlet #113613 08/14/02 03:26 AM
Joined: Jul 2002
Posts: 8,337
Trumpy Offline
Hi Ryan,
Thats a shocker.
At the end of that conduit, is that a
socket-outlet or a PIR sensor?
However, I don't like the look of this
installation at all.

Re: Exit sign and electical outlet #113614 08/14/02 08:09 AM
Joined: Oct 2000
Posts: 3,960
Bill Addiss Offline

That's a 'socket outlet' at the end, whose capacity is going to be governed by that tiny transformer that you see. (Transformer is only meant to light the 2 bulbs in the Exit sign)


Re: Exit sign and electical outlet #113615 08/14/02 12:18 PM
Joined: Apr 2002
Posts: 2,527
Bjarney Offline
The bogus 120V receptace may be feeding a plugged-in ~5VA wall wart and—irresponislbe as it is—may actually sort of work.

[Linked Image from]

Re: Exit sign and electical outlet #113616 08/14/02 12:22 PM
Joined: Nov 2001
Posts: 745
mamills Offline
Any idea what the capacity of the transformer is? Judging from its physical size, it doesn't look to be much larger than required to simply power the two lamps (the original intent, of course). It also appears that the lamps are burned out or have a lot of hours on them.

One more question; is the 277v. entry in the back center of the fixture? If so, it looks kinda like NM cable.

From an old codebook (I have a new one coming); Art. 700-13 - "No appliances and no lamps, other than those specified as required for emergency use, shall be supplied by emergency lighting circuits."

Mike (mamills)

[This message has been edited by mamills (edited 08-14-2002).]

Re: Exit sign and electical outlet #113617 08/14/02 08:38 PM
Joined: Apr 2002
Posts: 2,527
Bjarney Offline
The little transformer looks like maybe a 3-lead autotransformer—bet 15VA max.

[Linked Image from]

The rear-entry cable could be NM—with bare ground wire and possibly showing brown-paper fill.

Re: Exit sign and electical outlet #113618 08/15/02 06:41 AM
Joined: Dec 2001
Posts: 300
maintenanceguy Offline
The cable is NM with no clamp at the back of the exit sign. And this is a nursing home, I believe NM is only suitable in sleeping areas there anyway. This is the front lobby.

The outlet powers that little plug in transformer for a door alarm and apparently it worked that way for years.

I have no idea how big the transformer is, no marking on it at all.

Re: Exit sign and electical outlet #113619 08/17/02 01:29 PM
Joined: Apr 2002
Posts: 2,527
Bjarney Offline
Talk about a little knowledge being dangerous. This may have been a project designed and installed by the chairman and treasurer of the tuesday-afternoon ‘over-80’ engineering club...with its two active members—a retired telephone installer and career supply sergeant. ;-)

But they had the foresight of future-proofing—a spare outlet for the swill-mart carbon-monoxide detector when they go on sale in February. [Might have to wait ‘til one of the exit-sign lamps burns out to avoid overloading the 277-120V transformer.] They reached the sign with four stacked chairs from the piano room, and got materials by mail from the Sears and Roebuck catalog—summer 1955 farm & garden edition.


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