ECN Electrical Forum - Discussion Forums for Electricians, Inspectors and Related Professionals
ECN Shout Chat
ShoutChat
Recent Posts
Violation?
by renosteinke - 01/27/23 09:52 PM
Does NEC 551.71 (F) apply to dwellings?
by BigB - 01/20/23 10:46 AM
Power submeter connections
by HotLine1 - 01/19/23 09:09 AM
AFDD's coming to the UK
by Texas_Ranger - 01/17/23 07:22 PM
New in the Gallery:
Burger King crown sillyness
Burger King crown sillyness
by wa2ise, December 11
240/208 to a house
240/208 to a house
by wa2ise, October 9
Who's Online Now
0 members (), 123 guests, and 14 robots.
Key: Admin, Global Mod, Mod
Previous Thread
Next Thread
Print Thread
Rate Thread
Joined: Oct 2000
Posts: 3,672
Likes: 2
Admin Offline OP
Administrator
Member
Quote
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

Joined: Jul 2002
Posts: 8,432
Likes: 3
Member
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.

Joined: Oct 2000
Posts: 4,081
Likes: 3
Member
Trumpy,

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)

Bill


Bill
Joined: Apr 2002
Posts: 2,527
B
Moderator
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 67.115.161.42]

Joined: Nov 2001
Posts: 745
M
Member
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).]

Joined: Apr 2002
Posts: 2,527
B
Moderator
The little transformer looks like maybe a 3-lead autotransformer—bet 15VA max.

[Linked Image from 67.115.161.42]

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

Joined: Dec 2001
Posts: 300
M
Member
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.

Joined: Apr 2002
Posts: 2,527
B
Moderator
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.


Link Copied to Clipboard
Featured:

Tools for Electricians
Tools for Electricians
 

* * * * * * *
2023 National Electrical Code (NEC)
2023 NEC Now Available!
 
* * * * * * *

2020 Master Electrician Exam Preparation Combos
2020 NEC Electrician
Exam Prep Combos:
Master / Journeyman

 

Member Spotlight
Joe Tedesco
Joe Tedesco
Boston, Massachusetts USA
Posts: 2,749
Joined: October 2000
Top Posters(30 Days)
BigB 9
triple 3
Popular Topics(Views)
302,477 Are you busy
231,873 Re: Forum
216,498 Need opinion
Powered by UBB.threads™ PHP Forum Software 7.7.5