building firewall for two meters on same building

[bertristerf150hd]

I have been working on my shop with living quarters. I am looking to have two meters, 208 3 phase for the shop and single phase for the living quarters (tax purposes). I live in west texas and oncor told me that I need some kind of firewall to be able to have two meters on the same building. When they emailed me the paperwork for the 3phase stuff they were supposed to send me the specs for the firewall, but forgot. I emailed them back and it might be another week before i get an email back, like the last time. Any help would be appreciated

 

[mrb]

i think this firewall they are referrring to is a demising wall that divides the space into two seperate units. Why not just have one meter then submeter the feeder to the subpanel for your living quarters?

 

[Stuart in MN]

Chances are the information you need is in their construction guideline manual at http://www.oncor.com/electricity/construct/guidelines/const_guide.aspx

 

[bertristerf150hd]

Thanks for the quick replies and help

 

[theoldwizard1]

I am not an expert, but locally I have been told that an attached garage must have a "fire rated" wall between it and the home. 2 layers of 1/2" dry wall, taped and at least 1 coat of mud on both, running from the floor to the roof was adequate for that rating.

 

[Charles (in GA)]

I think the requirement for the firewall is in part because of a NEC requirement that generally does not allow for two separate services to the same structure. NEC 230.2 addresses this issue and 230.2(D) specifically allows two services to a single building or structure if the services are of different characteristics such as voltages, frequencies or phases or for different uses such as different rate schedules.

Charles

 

[Norcal]

I am not an expert, but locally I have been told that an attached garage must have a "fire rated" wall between it and the home. 2 layers of 1/2" dry wall, taped and at least 1 coat of mud on both, running from the floor to the roof was adequate for that rating.

1/2" drywall is not fire rated, one must 5/8" for a fire barrier.