Stand offs

[RichB]

Morning all,
I need a code referance, if there is one for the following:
We used to havwe a requirement to use a 1/4" stand off on all our surface mounted appertanances, ie, strut on a bridge or deck. This has recently been changed to say "as required" on our drawings. We, the inspectors and Maint, would like this to be put back to the opld wa--and get rid of the as required which our contractors are saying, and our engineers are agreeing, that if the conduit is straight we don't need to. We want it so dirt and debris do not accumulater on top of the strut, etc.

I have looked in 110, 300, 344 and 384, 2005 and 2008 and can't find anything. Our Engineer says he say it in an old NEC but can't find it now and won't change anything until we can find him a referance.

Any ideas folks?

Thanks in advance again!!

Rich

 

[Dennis Alwon]

I don't know any code that requires conduit on the outside to be fastened with standoff straps. Of course a 1/4" is required for panels etc but that is usually built into the enclosures.

 

[K8MHZ]

We called them 'back straps'. We used them with one hole straps to keep the conduit away from the wall for sanitary reasons. This was a requirement of the company, not a requirement of the NEC. I would recommend them in any area that is washed down.

 

[RichB]

Thanks guys. Yeah we used to use them behind everything that was surface mounted along the roadway. But because our Eng can't find it in the NEC he took it out, and when pressed he just says show me a code referance. He doesn't want to hear us, especially when we show him there is no code referance for other things we have--like a #8 min bond wire--that's ok but it is too expensive for the 1/4" standoffs--ah well thanks for the answers and letting me vent a bit.

 

[K8MHZ]

Thanks guys. Yeah we used to use them behind everything that was surface mounted along the roadway. But because our Eng can't find it in the NEC he took it out, and when pressed he just says show me a code referance. He doesn't want to hear us, especially when we show him there is no code referance for other things we have--like a #8 min bond wire--that's ok but it is too expensive for the 1/4" standoffs--ah well thanks for the answers and letting me vent a bit.

You may want to let the bean counter know that the back straps save on labor by not having to have an offset at each box. If using RMC, a box offset can take some time if you want perfect offsets. Think about having to put a box offset on a stub 90. Also, with no offsets, it makes the installation of the wire much easier. Most of the time it can just be pushed in, no fish tape needed.

I don't know if the back straps we used were 1/4 inch or not, but whatever they were they made the pipe line up perfectly with the knockouts.

 

[iamski]

Not sure if this will help your cause, 2005 NEC 300.6(D). Wet locations require !/4" airspace.

 

[renosteinke]

"Show me a code reference ..."

Well, if it's a place that handles food, there are spacing requirements in the health code.

My point is that there are more codes than just the NEC, and the schoolboy just might need to pay some 'tuition' to learn this lesson. Do it his way- and get a change order when/if it needs to be redone. After all, you tried to warn him.

 

[Dennis Alwon]

Not sure if this will help your cause, 2005 NEC 300.6(D). Wet locations require !/4" airspace.

Good find. Not sure if that pertains to the OP but I have missed that one. :thumbsup: