C.E.C 300.4 Protection against Physical Damage.

[former inspector]

The former PA inspector is the only inspector I have encountered enforcing this. When she first started enforcing it we got in a heated debate. She said she brought it up at the local inspectors meeting and all the inspectors agreed with her. I asked why she was the only inspector enforcing it then. Later I contacted inspectors that were at the meeting and was told they did NOT agree with her on this.

Hey Curt, it is sad to have them disagree on a required Code and that's the problem. When I was a Senior Inspector with the City, we got together, got the code out and got everyone on board, and call what ever we came up with. and Backed each other

 

[curt swartz]

I have seen lath staples right through and into the box on backside

The lath should be installed prior to the wiring.

I have been in the trade 42 years and have never had damage from nails/screws through the back box NM boxes. Could it happen? Sure!
The 4" screws the cabinet installer are more likely to damage cable in the walls.
The most common damage I have seen are nails driven through nail plates or fish hooking out the side of studs on double sided sheer walls.

 

[nizak]

The former PA inspector is the only inspector I have encountered enforcing this. When she first started enforcing it we got in a heated debate. She said she brought it up at the local inspectors meeting and all the inspectors agreed with her. I asked why she was the only inspector enforcing it then. Later I contacted inspectors that were at the meeting and was told they did NOT agree with her on this.

Yes siding guys are famous for finding that cable or box with a long nail. Around here most new houses are exterior wall framed with 2X6 lumber so that is no longer a problem.

With the Energy Code changes we to are seeing a lot of 2x6 exterior wall framing.

In the Northern climate here it got even worse in the Winter when siders would use longer nails because they were easier to handle with gloves on.

 

[acrwc10]

The former PA inspector is the only inspector I have encountered enforcing this. When she first started enforcing it we got in a heated debate. She said she brought it up at the local inspectors meeting and all the inspectors agreed with her. I asked why she was the only inspector enforcing it then. Later I contacted inspectors that were at the meeting and was told they did NOT agree with her on this.

I was at that meeting, all though she was over the top, it wasn't her that proposed the idea. And she retired as did the supervising inspector.
edited to add, The person who did suggest it was a contract inspector who has yet to hold a position longer than a year or two.

 

[Eddie702]

The protection requirements are basically for the cable passing through the studs and run on the studs. A plastic box and the cables entering it are offset from the stud. If the drywallers are hitting the stud as they should be they would not be screwing into a box or the cables entering the box.

I agree that is a big hope but if it was an issue the code would address it and we would have more pages to the cod.

A screw can penetrate EMT, FMC, PVC etc. where will it end if the can of worms is opened.?

 

[former inspector]

With the Energy Code changes we to are seeing a lot of 2x6 exterior wall framing.

In the Northern climate here it got even worse in the Winter when siders would use longer nails because they were easier to handle with gloves on.

Yes us too.....love 2x6 walls for plumbing, but some interiors are still 2x4

 

[former inspector]

The protection requirements are basically for the cable passing through the studs and run on the studs. A plastic box and the cables entering it are offset from the stud. If the drywallers are hitting the stud as they should be they would not be screwing into a box or the cables entering the box.

I agree that is a big hope but if it was an issue the code would address it and we would have more pages to the cod.

A screw can penetrate EMT, FMC, PVC etc. where will it end if the can of worms is opened.?

Totally agree !!! Its , in my opinion, silent in the Code, except the Verbiage that requires the protection.

 

[rc/retired]

My experience, I have never seen a problem with the cables entering the back of boxes. I'm sure it has happened.
I've seen more damage created by disgruntled employees.
Now, we collectively should invent a compliant nail plate to protect up to what 4, 5 gang device boxes. Or more? Probably something that spans the width of 16" framing members.
My opinion on this, I'm one who has installed and approved the standard inspection. Code be damned!

Ron

 

[infinity]

Totally agree !!! Its , in my opinion, silent in the Code, except the Verbiage that requires the protection.

IMO the current wording is there if someone wants to interpret that cable entering the box next to the stud requires protection. It should be spelled out more clearly. Basically as written there is a 1.25" square area next to the stud flush with the face of the stud that an unprotected cable cannot be in.

 

[LarryFine]

Now, we collectively should invent a compliant nail plate to protect up to what 4, 5 gang device boxes. Or more? Probably something that spans the width of 16" framing members.

No need to invent one; the plumbing department has them:

Simpson Strong-Tie PSPNZ 5 in. x 16-5/16 in. ZMAX Galvanized Protecting Shield Plate Nail Stopper PSPN516Z - The Home Depot

Nail stoppers help prevent nails from piercing pipes and electrical lines. Install over utilities that pass through framing members. PSPNZ protecting shield plate nail stoppers meet IRC, IBC and the International

www.homedepot.com

 

[former inspector]

IMO the current wording is there if someone wants to interpret that cable entering the box next to the stud requires protection. It should be spelled out more clearly. Basically as written there is a 1.25" square area next to the stud flush with the face of the stud that an unprotected cable cannot be in.

Thank you Infinity...That's the problem...I wish the Code would put more emphasis on this or give an exception to this location, but I was enforcing the parallel installed wires along the stud, making them move them back from the edge, per the code, protecting bores where the wire went through, then looking at the wires going into the box with the box even closer to the edge. Its hard because I do not try to enforce some codes and not on others because in my opinion I don't think its a problem. It is not "My opinion" on required codes on what to enforce, I just tried to do the right thing....

 

[former inspector]

No need to invent one; the plumbing department has them:

Simpson Strong-Tie PSPNZ 5 in. x 16-5/16 in. ZMAX Galvanized Protecting Shield Plate Nail Stopper PSPN516Z - The Home Depot

Nail stoppers help prevent nails from piercing pipes and electrical lines. Install over utilities that pass through framing members. PSPNZ protecting shield plate nail stoppers meet IRC, IBC and the International

www.homedepot.com

Larry that is basically what I am installing now, just a little smaller though.

 

[LarryFine]

Larry that is basically what I am installing now, just a little smaller though.

Simpson Strong-Tie PSPNZ 5 in. x 8 in. ZMAX Galvanized Protecting Shield Plate Nail Stopper PSPN58Z - The Home Depot

Nail stoppers help prevent nails from piercing pipes and electrical lines. Install over utilities that pass through framing members. PSPNZ protecting shield plate nail stoppers meet IRC, IBC and the International

www.homedepot.com

 

[former inspector]

Simpson Strong-Tie PSPNZ 5 in. x 8 in. ZMAX Galvanized Protecting Shield Plate Nail Stopper PSPN58Z - The Home Depot

Nail stoppers help prevent nails from piercing pipes and electrical lines. Install over utilities that pass through framing members. PSPNZ protecting shield plate nail stoppers meet IRC, IBC and the International

www.homedepot.com

Yes, sometimes stacked the little ones to make one big one to protect, LOL

 

[infinity]

Thank you Infinity...That's the problem...I wish the Code would put more emphasis on this or give an exception to this location, but I was enforcing the parallel installed wires along the stud, making them move them back from the edge, per the code, protecting bores where the wire went through, then looking at the wires going into the box with the box even closer to the edge. Its hard because I do not try to enforce some codes and not on others because in my opinion I don't think its a problem. It is not "My opinion" on required codes on what to enforce, I just tried to do the right thing....

The words are there to enforce protection. Without an exception for where the cable enters the box it's hard to argue that it's not required.

 

[former inspector]

The words are there to enforce protection. Without an exception for where the cable enters the box it's hard to argue that it's not required.

I totally agree and I really do appreciate your honesty and seeing this Code, for how it is written. Its has the exceptions stated for this location, rigid/intermediate conduit and nonmetallic conduit, etc... But other then the exceptions stated, it shall be protected.....I just wish it could be more in depth, or emphasized on through the Code makers, instead of what some folks are saying that its never been a problem and none do it or never seen it. In my professional opinion, it is a requirement that SHALL be enforced regardless of opinions, and that is what I am doing....I appreciate your understanding of this, and hope that this can someday be better explained or exempted....Consistency in the process is what we all strive for...

 

[infinity]

I totally agree and I really do appreciate your honesty and seeing this Code, for how it is written. Its has the exceptions stated for this location, rigid/intermediate conduit and nonmetallic conduit, etc... But other then the exceptions stated, it shall be protected.....I just wish it could be more in depth, or emphasized on through the Code makers, instead of what some folks are saying that its never been a problem and none do it or never seen it. In my professional opinion, it is a requirement that SHALL be enforced regardless of opinions, and that is what I am doing....I appreciate your understanding of this, and hope that this can someday be better explained or exempted....Consistency in the process is what we all strive for...

Around here no one enforces it even if it's technically required. You can simply install the protection on your job and move on regardless of whether or not the inspector is going to require it.

 

[former inspector]

Around here no one enforces it even if it's technically required. You can simply install the protection on your job and move on regardless of whether or not the inspector is going to require it.

So , basically enforce just parts of the code that one may think is needed , and don't enforce other parts. doesn't make any sense to me....I am installing them regardless just to meet the code requirements but wanted others opinions regarding this.

 

[don_resqcapt19]

IMO the current wording is there if someone wants to interpret that cable entering the box next to the stud requires protection. It should be spelled out more clearly. Basically as written there is a 1.25" square area next to the stud flush with the face of the stud that an unprotected cable cannot be in.

Panel 3 does not agree.

Public Input No. 1027-NFPA 70-2023 [ Section No. 300.4(D) ]
(D) Cables and Raceways Parallel to Framing Members and Furring Strips.

In both exposed and concealed locations, where a cable- or raceway-type wiring method is installed parallel to framing members, such as joists, rafters, or studs, or is installed parallel to furring strips, the cable or raceway shall be installed and supported so that the nearest outside surface of the cable or raceway is not less than 32 mm (11⁄4 in.) from the nearest edge of the framing member or furring strips where nails or screws are likely to penetrate. Where this distance cannot be maintained, the cable or raceway shall be protected from penetration by nails or screws by a steel plate, sleeve, or equivalent at least 1.6 mm (1⁄16 in.) thick.

Exception No. 1: Steel plates, sleeves, or the equivalent shall not be required to protect rigid metal conduit, intermediate metal conduit, rigid nonmetallic conduit, or electrical metallic tubing.

Exception No. 2: For concealed work in finished buildings, or finished panels for prefabricated buildings where such supporting is impracticable, it shall be permissible to fish the cables between access points.

Exception No. 3: A listed and marked steel plate less than 1.6 mm (1⁄16 in.) thick that provides equal or better protection against nail or screw penetration shall be permitted.

Exception No.4 Entrance to a device box installed on wood or metal studs, the cable can be within (1.6mm) 1.25 inch from the framing member and no more than 6 inches above or below the device box.

Statement of Problem and Substantiation for Public Input
Cables entering a deep device box on 4 inch studs require the cables to be closer than allowed per 300.4. Allowing and exception will give the electrical contractor 6 inches below, or above the box to be closer than required per 300,4

Committee Statement

Resolution:

Nails or screws are likely to penetrate cable or raceways within 6 inches either above or below a device box if the 1 ¼” spacing from the nearest edge of the framing member is not maintained. Where this distance cannot be maintained, the cable or raceway shall be protected from penetration by nails or screws by a steel plate, sleeve, or equivalent at least 1.6 mm (1 ⁄16 in.) thick.

 

[infinity]

Panel 3 does not agree

They don't agree with which part of my statement? They said that if the spacing cannot be maintained at the box then it must be protected. I said the same thing.