What is Article 720 referring to?

[jason sleeth]

A local Municipality has added an amendment to 720.11 as follows:

720.11 Mechanical Execution of Work. Circuits operating at less than 50 volts
shall be installed in a neat and workmanlike manner. Cables shall be supported
by the building structure in such a manner that the cable will not be damaged by
normal building use. ***All low voltage-type wiring systems shall be installed in
an approved raceway system acceptable to the Building Official. Non-metallic
raceway systems allowed for residential use only. Commercial concealed low
voltage-type wiring systems to be installed in metallic raceways***

Their intent was to require TV and phone to be run in conduit. The are incorrectly citing the code and should be referring to Section 8 Articles like 800 and 820 instead of chapter 7 articles.

720.4 states that the min conductor size is #12 etc. obviously not intended for tv and phone applications.

Can someone give me examples of what this section is referring to? Lighting controls under
50 volts like a mark 7 ballast or is it something entirely different?

 

[iwire]

I am not sure what it does apply to but it most certainly does not apply to TV and phone.

 

[480sparky]

I don't think I've ever encountered TV and Phones that use 12 AWG.

 

[Hendrix]

A local Municipality has added an amendment to 720.11 as follows:

720.11 Mechanical Execution of Work. Circuits operating at less than 50 volts
shall be installed in a neat and workmanlike manner. Cables shall be supported
by the building structure in such a manner that the cable will not be damaged by
normal building use. ***All low voltage-type wiring systems shall be installed in
an approved raceway system acceptable to the Building Official. Non-metallic
raceway systems allowed for residential use only. Commercial concealed low
voltage-type wiring systems to be installed in metallic raceways***

Their intent was to require TV and phone to be run in conduit. The are incorrectly citing the code and should be referring to Section 8 Articles like 800 and 820 instead of chapter 7 articles.

720.4 states that the min conductor size is #12 etc. obviously not intended for tv and phone applications.

Can someone give me examples of what this section is referring to? Lighting controls under
50 volts like a mark 7 ballast or is it something entirely different?

#12 speaker wire is fairly common.

 

[raider1]

Article 720 regulates any circuit or equipment that operates at less than 50 volts that is not regulated by other Articles or sections in the NEC.

720.3 gives a list of sections and Articles in the NEC that are not regulated by 720.

720.2 Other Articles.
Direct current or alternating-current installations operating at less than 50 volts, as covered in 411.1 through 411.7; Part VI of Article 517; Part II of Article 551; Parts II and III and 552.60(B) of Article 552; 650.1 through 650.8; 669.1 through 669.9; Parts I and VIII of Article 690; Parts I and III of Article 725; or Parts I and III of Article 760 shall not be required to comply with this article.

Also Chapter 8 and the Article contained within Chapter 8 are not required to comply with the rest of the NEC unless specifically referenced in Chapter 8.

This means that 720 would not apply to communications, CATV, Radio and television equipment etc....

Chris

 

[charlie b]

This thread was posted twice, the other being in the Low Energy forum, and both versions had other comments posted in them. We do not allow duplicate discussions here. So I combined all comments from both threads into this single thread.

 

[iwire]

Thanks Mr. Beck.

 

[LarryFine]

That's why you get the big bucks, CB.

 

[tom baker]

Article 720 goes back to the depression. Goggle Delco Farm Plants. Before REA, farmers had DC power plants, wind and small gas engines. The gas generator would automatically start to charge the battery bank. Sales reps would come by at night and show the Misses lights, coffee makers and then a sale was made.
Your local municipality has the scope wrong. Coax is article 820, in the communications chapter....
I don't have my NFPA handbook, if someone has it see what it says.

 

[e57]

So what could it apply to? Access and door intercom wiring?

 

[jason sleeth]

thanks, that was an interesting search. An inspector told me he thought it was pertaining to electrical systems on farms.. should have asked some more questions.

 

[dbuckley]

... Delco Farm Plants. Before REA, farmers had DC power plants, wind and small gas engines.

Thanks for that; I know from folklore that "even the 32 volt power systems used on farms have been known to kill people" but never knew where or what these 32V systems were.

And now I do