Electric Sub-Panel Installation

[tc35dforme]

Seems like a simple solution that isn't coming to me.....

I've installed many panels, but for my addition, I'll have a flush installation between studs in a wall. My question....since the panel is 14.25" wide, there will not be room for romex clamps at the box to secure the branch wiring. What am I missing ?? Do I need to header off the stud space to allow for a wider rough opening ??? Do I invert the clamps with the locking collar inside ????

Anyone have an answer to my stupid question ???

 

[TonyV]

Why can't the circuits come into the top/bottom of the box??

...Tony

 

[slowrev]

Yep, use the top and bottom of the box, I think many panels don't even have knockouts in the sides, and seem to be designed for top/bottom access only.

Ben

 

[LarryD]

Top and bottom, like Tony said. There should be knockouts across the width of both locations.

 

[timb]

On a sub-panel like that, what are the applicable rules relative to permanent access/location?

 

[Farwell]

Not a stupid question and your idea of using a header is a good idea in some applications. In most cases using the upper and lower knock-outs is the easiest and most used way but sometimes things dictate that you have to go the other route which I have done many times and it works fine.
When it comes time to run your sub-panel supply wire, if you are running 220-volts, run four wires. Two hot legs, one neutral leg and one ground (or bonding) leg. The reason I mention this is that my pole barn has the three legs running from the main and I would be more comfortable if I had the ground (or bonding ) leg running back to my main panel.

 

[BigAl]

Farwell ,
Could you not just drive a ground rod at the barn and attach a ground wire from it to your barn panel . Seems to me you would end up with the same thing as sending a ground wire all the way to the main panel as well as saving a few dollars . The building inspectors around here love more than one grounding source .
Allen

 

[tc35dforme]

Like I said...the answer was obvious, but not coming in......

The top and bottom knockouts are the answer.....never even thought..... /forums/images/graemlins/crazy.gif

Thanks for the wake up guys !!!!

 

[Farwell]

Al,
The inspectors in my area want the three leg run with the two ground rods driven 6 feet apart at the pole barn and the neutral bonded to the sub-panel along with the ground (or bonding) leg so this is the way I did it because the three legs were run and buried before I purchased the property.
You would not believe the many different opinions on this issue that I have run across.
Yes you are right it is pretty much the same thing but being **** like I am I wanted the extra insurance in case I lost the neutral leg for some reason.

 

[Farwell]

Al,
Re-read your post and wondered if you knew that the secondary ground at the sub panel needs to go back all the way to the main panel box because earth ground at the sub panel has too much resistance to work well as a path back to the third leg coming off of the electric pole transformer that is tied into the main panel and earth ground rod driven at the main supply input point. That is why the neutral and earth ground at the sub panel are bonded in the sub panel box. This is something I learned from reading Mike Holt's Grounding and Bonding information on his web site.
This is probably going to start some serious discussion but this is what I have gleaned over the past year of researching. May be wrong but it makes sense to me.