Need help with sub panel wiring.

James Edwards · 10-23-2008, 04:10 PM

Hello, i am new to this site and was wanting to know if I can get some help with wiring my shop sub panel. When we moved hear there was a overhead wire going to our shop that they were going to hook up and did not. It has two aluminim wires one neatraul ground and hot. I got a 100 amp d square sub panel and 20 amp breakers. I have netraul ground hooked up to the netraul bus bar and the hot hooked to the hot. My question is do I hook up a Ground rod to the ground bar? Should there be another ground coming from the house? Thank you. James

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**Jim Luttrall** · 10-23-2008, 04:21 PM

The best help I can give you is to tell you not to do this yourself, get a qualified electrician, pull the permits and do this the right way. People have died from screwing with this type of arrangement. Even people who should know how screw it up frequently. It is not the danger of working on it and getting it to work but it is the stuff that goes wrong when you hook it up incorrectly and someone gets killed after you finish because important steps were done wrong.
No offense intended, but if you have to ask, you are not qualified to do the work and can kill someone.

**Jim Robinson** · 10-23-2008, 04:27 PM

If you literally only have two wires coming, it's not going to work very well. There should be at least three, with two hot and one neutral. Even then, you would need to install a ground rod. There are other parameters that may require a fourth wire.

I would contact an electrician and get it done properly.

Ron Bibler · 10-23-2008, 04:30 PM

James. a qualified electrician is Cheap money. I just had a new Main panel installed in my home. $ 695 bucks thats with the new panel and the works... And i have a very good understanding of this stuff.
The best part of my understanding is don't mess with it...

Take Big Jims advise. Get a qualified electrician on it...

Best

Ron

Richard Pultar · 10-23-2008, 05:08 PM

no additional ground allowed per national electric code. there is nothing you need to get excited about .

**Gunnar Alquist** · 10-23-2008, 05:26 PM

Originally Posted by James Edwards

Hello, i am new to this site and was wanting to know if I can get some help with wiring my shop sub panel. When we moved hear there was a overhead wire going to our shop that they were going to hook up and did not. It has two aluminim wires one neatraul ground and hot. I got a 100 amp d square sub panel and 20 amp breakers. I have netraul ground hooked up to the netraul bus bar and the hot hooked to the hot. My question is do I hook up a Ground rod to the ground bar? Should there be another ground coming from the house? Thank you. James

James,

Proper grounding and understanding of grounding is difficult and many people get it wrong. Depending on where the shop is and other factors which include plumbing, phone, fences (really), safe and proper wiring can be different. I regularly see "professionally" installed electrical that was incorrectly wired.

With very few exceptions, the neutral and ground should be isolated, not bonded (connected) together. This would mean at least one "hot", one "neutral" and one grounding conductor. As Jim indicated earlier, depending on your needs and use, 240 v single phase would probably be your best bet. A buried conduit with properly sized cables would be my preference. As has been said, the safest choice would be to get an electrician to give you a properly wired shop. He/she will calculate your needs and bring in adequately sized feeder cables. You can help to defray costs by trenching, laying pipe and pulling wire. Leave the sizing and connections to the licensed electrical contractor. Really. Please. We don't want to read about your fire or death in next weeks paper.

**Jim Port** · 10-23-2008, 05:27 PM

Originally Posted by Richard Pultar

no additional ground allowed per national electric code. there is nothing you need to get excited about .

If you are referring to a ground rod, if this outbuilding is served by more than 1 circuit a ground rod(s) is(are) required.

If this is a separate service to the outbuilding a grounding system would be required also.

**Jerry Peck** · 10-23-2008, 05:30 PM

Originally Posted by Richard Pultar

no additional ground allowed per national electric code. there is nothing you need to get excited about .

Richard,

Show me.

Post the code section.

As I read what he wrote, you are thinking of something which does not apply.

**Don Norman** · 10-27-2008, 09:42 AM

Hi Jim,

I have to agree with the others that you REALLY need to have the subpanel installed by a qualified electrician.

For the purposes of inspection here's what you would like to see. The feeder should be a 4 conductor feeder - 2 hots, a neutral and grounding conductor. If the workshop is in a separate building the sub panel should have it's own separate driven ground rod with the grounding electrode conductor connected to a grounding bus in the sub panel enclosure. The grounding conductor from the feeder is connected to the grounding bus as well.

Originally Posted by James Edwards

Hello, i am new to this site and was wanting to know if I can get some help with wiring my shop sub panel. When we moved hear there was a overhead wire going to our shop that they were going to hook up and did not. It has two aluminim wires one neatraul ground and hot. I got a 100 amp d square sub panel and 20 amp breakers. I have netraul ground hooked up to the netraul bus bar and the hot hooked to the hot. My question is do I hook up a Ground rod to the ground bar? Should there be another ground coming from the house? Thank you. James