What is a Dead Front?

[synchro]

So a cord plugged into a receptacle is exposed live parts as well?

If you didn't plug it in all the way, or didn't pull it out all the way, then yes. A partially inserted plug exposes the live prongs of the plug. ...

I find it interesting that the British BS 1363 plug has an insulating sleeve on the inner half of the prongs, and it also has to be pushed in beyond the halfway point to make any electrical contact. As a result, there is never any exposed portion with a dangerous voltage on it no matter how far the plug is inserted.

https://www.plugsocketmuseum.nl/British1.html

 

[LarryFine]

I find it interesting that the British BS 1363 plug has an insulating sleeve on the inner half of the prongs, and it also has to be pushed in beyond the halfway point to make any electrical contact. As a result, there is never any exposed portion with a dangerous voltage on it no matter how far the plug is inserted.

US plugs don't leave much prong exposed by the time they reach the receptacle contacts either.

You really do have to curl your fingertips around the face of plug body to touch the blades.

 

[Dennis Alwon]

So a cord plugged into a receptacle is exposed live parts as well?

Do you really see a panel cover open as shown on the same level as a receptacle? They actual made receptacles harder to get into because of safety so yes the receptacle did have exposed parts, in a sense.

 

[jim dungar]

US plugs don't leave much prong exposed by the time they reach the receptacle contacts either.

You really do have to curl your fingertips around the face of plug body to touch the blades.

Have you seen the TIK TOK video challenging kids to put a dime between and phone charge and the outlet? It was just in the news, this past week.

 

[synchro]

US plugs don't leave much prong exposed by the time they reach the receptacle contacts either.

You really do have to curl your fingertips around the face of plug body to touch the blades.

On the few that I checked, the prongs have to be inserted approximately halfway before they start making contact, at which point they leave from 0.3 to 0.34 inches exposed. So yes there's not that much exposed, but it was relatively easy to get my pinky finger to just touch a prong when it first makes contact. Fatter fingers would be more immune, but those of children could probably make such contact relatively easy. That said, I haven't heard finger contact being much of a problem.

The other thing is that the British plug will not get shorted if a metal object is inserted across exposed prongs.
I just saw Jim's post now, which is right to point on this issue.

 

[Hv&Lv]

Funny story… now anyway, it wasn’t then.
my son was a small toddler playing around the house. (Early 80s)
my then wife and I were in the kitchen. We noticed the lights dim then come back on followed by the shrieks of a child…
my son had plugged in a lamp.

Apparently his fingers were small enough to touch the prongs as they are inserted..

 

[infinity]

the total of all of the pieces required to close off access to the live parts.

In the picture, what is the access path to live parts? To those unfamiliar with that product, it appears there are none at present. The depth of the grey painted metal relative to the outer box is not clear, and I assume there are solid sides behind the edges of the grey painted metal. If not, and you could reach around behind it to get to the bus or exposed lugs on the breakers, then I agree it is not dead-front.

Cheers, Wayne

Yes, there are live parts behind the gray inner cover that can be accessed by reaching around the cover. Different panel but you can see what's exposed.

 

[Dennis Alwon]

Nice neat work to whoever did it...

 

[ActionDave]

Do you really see a panel cover open as shown on the same level as a receptacle? They actual made receptacles harder to get into because of safety so yes the receptacle did have exposed parts, in a sense.

Not precisely, but in a general sense yes. A cord plugged into an energized receptacle presents similar dangers to a panel with the cover open but "dead front" on. In both cases the only immediate exposure to anything energized is the insulated wires.

 

[ActionDave]

Yes, there are live parts behind the gray inner cover that can be accessed by reaching around the cover. Different panel but you can see what's exposed.



View attachment 2558875

And following up with my previous posts that picture shows that, while indeed you can get your fingers into some live stuff if you are hell bent on doing so, you can't just casually put your fingers around the edges of the metal and get shocked. The clearances to the live parts are generous.

 

[norcal]

Live front attachment plugs have the screws accessible from the prong end, think of the ones that have the fiber disc that was replaced after wiring, they were prohibited by the NEC beginning Jan 1st, 1978.

 

[ggunn]

Perhaps I'm being picky, but I think of "dead-front" as an adjective, not as a noun.

The deadfront is whatever keeps you from becoming dead. It isn't necessarily any single piece of metal.

 

[infinity]

Nice neat work to whoever did it...

I agree, that wasn't done by me. I happened to be working in an electric closet and the covers were off.

 

[DrSparks]

Another example. Dead front covers all the live parts but the cover can remain off allowing access to the gutters.

Sent from my BE2028 using Tapatalk

 

[rambojoe]

Yes, there are live parts behind the gray inner cover that can be accessed by reaching around the cover. Different panel but you can see what's exposed.



View attachment 2558875

Who taught you to not like bends?! I treat all wires like a stranded bundle. That looks great!
I think the word "dead to all traffic and safe for tools and supplies hitting it.
Edit.. sorry, who's work is it?

 

[infinity]

Another example. Dead front covers all the live parts but the cover can remain off allowing access to the gutters.

Sent from my BE2028 using Tapatalk

That inner cover in the photo is not covering all of the live parts.

 

[norcal]

That inner cover in the photo is not covering all of the live parts.

Once the panel front is installed the whole assembly is a dead front, there are no live parts exposed.

 

[hillbilly1]

I think in todays terms “dead front” would be the complete assembly, but in the past, it would actually mean “dead front” not dead sides. It was very common years ago to pull wire into live panels, along with testing and troubleshooting. It was safer with the inside cover on, and lessening the exposure hazard.

 

[LarryFine]

It seems like all modern electrical equipment made today is dead-front, at least when assembled.

Is there any live-front equipment even being made anymore?

 

[Fred B]

Who taught you to not like bends?! I treat all wires like a stranded bundle. That looks great!
I think the word "dead to all traffic and safe for tools and supplies hitting it.
Edit.. sorry, who's work is it?

https://forums.mikeholt.com/attachments/2558875/

Does look pretty
While it looks to be technically compliant for 200.4(B), I've had to do service work in such panels where it had similar bundles and just wire markers of the tape type similar to picture, where the identification requirements for 200.4 no longer visible. It became a real PIB to find all associated circuit conductors for an individual circuit.
My preference, as a result, has been the use of cable ties for purpose of 200.4 and not relying on the label tape only.