What is a Dead Front?

[infinity]

As the title asks what is a dead front? In the photo below the panel has a two part cover, an inner trim (shown) and a cover (not shown). Some say that the inner trim is the dead front but the definition in the NEC seems to say otherwise. IMO the combination of the inner trim and the outer cover make up the dead front. For a residential style panel the two are connected together so the point is moot. Any opinions?

Article 100: Dead Front. Without live parts exposed to a person on the operating side of the equipment.

 

[Dennis Alwon]

The picture shown has exposed parts and can be dangerous. Just because you cannot see the terminations doesn't mean that you are out of harms way. So the outer cover is the dead front, Imo

 

[Carultch]

IMO the combination of the inner trim and the outer cover make up the dead front.

Agreed. All of what is necessary to make no live parts exposed or readily accessible to the user, is what I would consider the complete dead front. If built in multiple components, I might call one of the components "a" dead front, or I might call them the dead fronts (plural), with the implication that they all form the dead front collectively.

The code definition seems to be using dead front as an adjective, rather than as a noun. Though the word works for both grammar categories the way I typically hear it used. It is describing the panelboard as a dead front panelboard. All of the components needed to block access to the live parts, are all needed to classify the panelboard as a dead front panelboard.

 

[kwired]

The picture shown has exposed parts and can be dangerous. Just because you cannot see the terminations doesn't mean that you are out of harms way. So the outer cover is the dead front, Imo

But if you leave the inner cover off and install the outer cover only you still can have exposed live parts. The two together on this particular application make up the dead front.

I've seen some (usually older ones) where the outer cover attaches to the inner cover in some way - those you can't attach the outer cover without the inner cover, without making modifications anyway.

 

[kwired]

More common with 3R/12 types of enclosures to have a "deadfront" as well as another door that only gives it a 3R/12 rating when it is closed.

Get into some larger panelboards and the "deadfront" might be several pieces that all need to be installed before you have created a "dead front"

 

[kwired]

I've used many NF and NQ panels in recent years. Depending on how you build it - I have often had a cover for the main breaker section, one for the branch breaker section, if over 42 circuit panel maybe even more than one piece for this, one for feed thru lugs section if you have this, then still one or more pieces that trim it all out.

 

[Dennis Alwon]

Of course, I didn't mean to say the inner cover could be off. I am saying removing the outer cover alone creates the hazard

 

[kwired]

Of course, I didn't mean to say the inner cover could be off. I am saying removing the outer cover alone creates the hazard

Just saying some cases those pieces are dependent on one another to make a complete assembly of some sort, others they are fairly independent of one another - though they still need the others to make up the entire "deadfront".

 

[Hv&Lv]

IMO your picture is dead front. At the operating position there are no live parts.(or none I can see)






Live fronts:


Dead Fronts:



And from the manufacturer:

 

[zbang]

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

 

[ActionDave]

As the title asks what is a dead front? In the photo below the panel has a two part cover, an inner trim (shown) and a cover (not shown). Some say that the inner trim is the dead front but the definition in the NEC seems to say otherwise. IMO the combination of the inner trim and the outer cover make up the dead front. For a residential style panel the two are connected together so the point is moot. Any opinions?






View attachment 2558867

I've always called this a Dead Front.

 

[ActionDave]

The picture shown has exposed parts and can be dangerous. Just because you cannot see the terminations doesn't mean that you are out of harms way. So the outer cover is the dead front, Imo

Agreed. All of what is necessary to make no live parts exposed or readily accessible to the user, is what I would consider the complete dead front...

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

 

[infinity]

I've always called this a Dead Front.

You're referring to the inner trim in the photo I posted?

 

[Hv&Lv]

You're referring to the inner trim in the photo I posted?

I am. I realize you didn't ask me specifically.
One would have to reach behind the panel and try to get hurt operating a breaker

 

[ActionDave]

You're referring to the inner trim in the photo I posted?

Correct.

 

[infinity]

Correct.

Others have expressed the same opinion and at one time I was taught that. When I had this discussion with a few sparky's some said the inner portion is the dead front and others said it was the total of all of the pieces required to close off access to the live parts. When looking at the Article 100 definition I would agree with the latter.

 

[Carultch]

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.

There's a good reason why the receptacle is female and the plug is male, as we'd be asking for trouble if we built them the other way around.

I suppose my earlier part could also be used to make the case that a non-TR receptacle also has exposed live parts. Although it does require a "tool" to contact them, even a tool as simple as a paperclip used in a dangerous way.

 

[Hv&Lv]

Others have expressed the same opinion and at one time I was taught that. When I had this discussion with a few sparky's some said the inner portion is the dead front and others said it was the total of all of the pieces required to close off access to the live parts. When looking at the Article 100 definition I would agree with the latter.

Just my opinion, but if it was a total of all the pieces, then the dead front pictures I posted above would be considered live front because the doors aren’t shut?

 

[Tulsa Electrician]

I would say the inner cover posted in the picture is part of the dead front assembly.
In that case additional parts are required for it to meet MFG listing.

In the field this has came up a lot and I always tell the guys put all the covers on just not the the breaker cover. If it ruptured you would be exposed.
I also them them when you do current test with the outer cover removed you fall under OSHA for arc flash and basic safety guidelines.
Use your LOTO and I don't mean gamble. It's not worth it.

 

[wwhitney]

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