Nail Plates for LV ?

[bscon321]

There are rules stating that wiring run within two inches from or under furring strips must have nail blockers installed. I understand the rule for any class 1 wiring like romex, drywall screws and fires. But for alarm wires or LV does it the NEC rule apply. It?s a good practice rule, but in most cases it over kill like when a wall has a 1-inch foam insulator board.
There is plenty of room behind the board to go thru the foam and you would have to put nail plates up and bulge the drywall. I'm looking in the NEC book right now but was looking for some real world knowledge.

 

[hbiss]

No there isn't because there is no safety issue. The problem of fasteners damaging the LV wiring is still there however, so if you want to be sure there will be no problems observe the 1-1/4 " rule and use nail plates as you would with class 1 wiring. In my opinion it's cheap insurance.

I also don't buy the bulging sheetrock argument. I get that from primidona GC's. If it's noticible that's what tapers are for.

-Hal

 

[ryan_618]

Limited energy circuits must comply with 300.4(D), which is for circuits and conductors that are parrlellel to framing members. This is becasue a class 3 circuit is still not safe from electrical shock, but it is safe from fire.

I made proposals to delete all nail plate requirements for limited energy circuits, based on two things:
1) It is not a safety issue, for the most part, and
2) IT only applies to parrallel framing installations, not bored holes.

I wouldn't be surprised to see the CMP's accept this in principal in part, and revise it so it refers to 300.4 and not just 300.4(D), which would go against my entire proposal!

 

[pierre]

725.8 Mechanical Execution of Work.
"... The installation shall also conform with 300.4(D)" - which is the 1 1/4 inch requirement.



725.8 is located in PART I of Art 725.
PART I is tittled, General. Which means that all of the requirements in that PART are applicable to Art 725 unless one of the other PARTS modify or supplements it.

 

[bscon321]

Thanks for the interest in the subject. It comes up more than it should. Especial with the primadonna GC's I work with. Some want more some want less and then the inspector interprets the code his way and ask for more. I usually put on to many to cover myself. I didn't want go up against the inspector with out some good info. I just went back and add more than the GC wanted. At least he will pass for now. Thanks

 

[ryan_618]

It's a tough subject, becuase the NEC seems to want nail plates for power limited circuits, but it only requires them part of the time