ProSoundWeb Community

Sound Reinforcement - Forums for Live Sound Professionals - Your Displayed Name Must Be Your Real Full Name To Post In The Live Sound Forums => Installed Sound/Contracting => Topic started by: Jonathan Novick on May 26, 2014, 02:21:50 AM

Title: Codes for 70v outdoor systems
Post by: Jonathan Novick on May 26, 2014, 02:21:50 AM
Can anyone point me to the codes that would relate to installing 70v systems in outdoor locations?

I am particularly interested in knowing if temporary connections can be used and if so, what are the requirements for them. There are IP67 rated connectors used for architectural lighting that seem like they could also be used for 70v systems. However, I cannot even find these connectors on Digikey's website.
Title: Re: Codes for 70v outdoor systems
Post by: Hal Bissinger/COMSYSTEC on May 27, 2014, 12:36:57 PM
Other than clearance above roads and driveways for aerial runs there are no NEC articles that apply to outdoor low voltage. However you should check with the local jurisdiction as sometimes they amend the NEC with their own requirements. As far as connectors go knock yourself out.

-Hal
Title: Re: Codes for 70v outdoor systems
Post by: Lee Douglas on May 28, 2014, 12:09:00 PM
Can anyone point me to the codes that would relate to installing 70v systems in outdoor locations?

Check out Article 640 in the NEC.  It refers heavily to Articles 400 and 725, specifically 640.21(B) and 640.42(B).  I not sure specifically whether yours is a temp or permanent install, but in my experience, there are usually product skews for each application and they will generally include the appropriate connection at the enclosure for its intended use.  As was said, check with the local AHJ when in doubt and get it in writing.
Title: Re: Codes for 70v outdoor systems
Post by: Hal Bissinger/COMSYSTEC on May 28, 2014, 11:36:17 PM
Check out Article 640 in the NEC.  It refers heavily to Articles 400 and 725, specifically 640.21(B) and 640.42(B).  I not sure specifically whether yours is a temp or permanent install, but in my experience, there are usually product skews for each application and they will generally include the appropriate connection at the enclosure for its intended use.  As was said, check with the local AHJ when in doubt and get it in writing.

With the possible exception of outdoor carnivals, fairs, circuses and concerts (and even there it only addresses power to the systems) I see no requirements for outdoor installations in Art 640.

The NEC is concerned with the protection of life and property therefore you won't see much in the way of LV (limited to the spread of indoor fire and smoke). Outdoor LV simply doesn't present a hazard to life and property.

Also, the NEC is not a design manual so don't expect to see it specify what connectors to use although common sense dictates that for LV you use something that cannot be connected to line voltage by mistake.

Lastly, the NEC is not a book that you can pick up and take sections out of context from the rest of the book. You have to understand the entire Code before you can make a judgement as to whether an article applies to your situation because each section and article often relies heavily on other articles as well as an understanding of the way the book is written. Article 400 for instance does not apply to LV unless an Article or section in Art 725 or Art 800 on points back to it.

-Hal
Title: Re: Codes for 70v outdoor systems
Post by: claude cascioli on June 20, 2014, 09:15:54 AM
Can anyone point me to the codes that would relate to installing 70v systems in outdoor locations?

I am particularly interested in knowing if temporary connections can be used and if so, what are the requirements for them. There are IP67 rated connectors used for architectural lighting that seem like they could also be used for 70v systems. However, I cannot even find these connectors on Digikey's website.

i been doing 70 volt systems .your best bet is follow this all cables should be at least 13 ft over walk ways and 18 ft over driveways and it best to use uf type cable ( can be found at home depot or any electric supply house for overhead wiring.
as far as connectors for speakers .there called speakons