300 Volt barriers

[ryan_618]

I would like to know how some of you electricians comply with article 404.8(B). Every time I red-tag an installation for this, I am told that nobody makes anything to achieve this sepration between (2) 277V swithches.

(Of course I am told this after they tell me that I'm the only person in the world that requires it )

[ October 02, 2003, 01:13 PM: Message edited by: ryan_618 ]

 

[gregoryelectricinc]

Re: 300 Volt barriers

Ryan, they are made. I'm sure steel city has them, I just don't know the part # of the top of my head. That's what the lille slots in multi-gang p-rings are for, to hold the barrier in place. The biggest mistake i see made id with the pipework to a box that neds a barrier installed. Easiest thing to do is run a pipe from each "section" of the box out of the wall to the ceiling box. That way you do not have to cross wiring behind the barriers to get thenm into the proper switch compartment. BTW, you are not the "only inspector in the world" that watches for this and requires this. The other option I see quite often is to try to make sure all switches in the multi-gang box are on the same phase of the panel. This does away with the over 300 volts between adjacent poles.

 

[BAHTAH]

Re: 300 Volt barriers

I use a RACO 4" square box partition. They are made for 1-1/2" and 2-1/8" deep 4S boxes and available at most every supplier.

 

[don_resqcapt19]

Re: 300 Volt barriers

Ryan,
Look at the slots in the plaster rings for metal boxes. These slots are to support the front edge of a box divider. I don't use nonmetallic boxes, but beleive that some of them have slots in the top and bottom for holding section dividers.
The other problem is that each section of the box must have its own conduit entry because the dividers do not permit wires to pass from section to section.
Don

 

[frenchelectrican]

Re: 300 Volt barriers

yes indeed i did look at the metal box and yes they have notched for diver but i did not get chance to get the part number. ( for raco boxes )


i talked with bob ( Iwire) and yes try to keep at the same phase to advoid and i did look at nec codes they dont mention not too much about running the wire behind but what don did bring up and he is correct about the diver portaion piece , yes i rember it correctlly that for seprate phase have to bring seprate conduct


merci , marc

 

[ryan_618]

Re: 300 Volt barriers

Thanks guys. I figured someone had to make them but I keep getting told they can't find any. Thanks a lot.

 

[roger]

Re: 300 Volt barriers

Ryan, like the others I don't have a part # right now but we use alot of both metal and plastic dividers (what ever is in stock) to seperate critical and normal power switches in health care facilities.

Roger

 

[cselectric]

Re: 300 Volt barriers

Tell the naysayers to order T&B Cat# 52PS-1 (for 1 1/2" deep boxes) or #52PD-1 (for 2 1/8" deep.)

Without dividers, the only ways to comply with 404.8(b) are

1. assure all switches in a given box are on the same phase.
2. Low voltage switching.
3. Put each switch in it's own box.

Given those three options, I'm betting those who complain will suddenly find a source for dividers.