Subpanel - Connecting Ground and Neutral in main panel

[Prometheus]

So I'm almost done installing my subpanel, and I'm 99% certain how to do the final connections, but I just want a sanity check.

Ground and Neutral have separate bars in the subpanel, neutral is not bonded. In the main panel, neutral IS bonded and all the ground and neutral wires go to the same bar. When connecting my subpanel feeder wires BOTH neutral and ground wires connect to the neutral bus bar, correct? Thanks.

 

[wyliesdiesels]

Correct

 

[justsam]

Is this subpanel in a detached structure? If so, you will need ground rods at the subpanel location.

 

[jdieter]

Is installing a ground rod for a detached structure sub-panel a NEC requirement? I've been out of the electrical game for several years, the last code book I have is 1996 and I can't find it.

 

[Samh]

Is installing a ground rod for a detached structure sub-panel a NEC requirement? I've been out of the electrical game for several years, the last code book I have is 1996 and I can't find it.

They allow both approaches for a detached structure. but you would only bond at the sub panel if running a ground rod, otherwise ground runs with feeder wires.

For in the same dwelling, you ground back to main panel, which is bonded with neutral.

 

[acer66]

They allow both approaches for a detached structure. but you would only bond at the sub panel if running a ground rod, otherwise ground runs with feeder wires.

For in the same dwelling, you ground back to main panel, which is bonded with neutral.

If I remember correctly right now a detached structure has to have two ground rods if in the US.

 

[rlitman]

When connecting my subpanel feeder wires BOTH neutral and ground wires connect to the neutral bus bar, correct?

In the main panel? You may have two bus bars, but since they're bonded, each one is the same. Only in the subpanel do you need to worry about keeping neutral and ground on separate bars.

 

[Showkey]

Question...............If you have 4 wires from the main panel, what is the symptom or problem with no ground rod at the remote panel ???

4 wires = 2 power, neutral and ground

 

[rlitman]

Question...............If you have 4 wires from the main panel, what is the symptom or problem with no ground rod at the remote panel ???

4 wires = 2 power, neutral and ground

I believe the main issue is with lightning and a detached structure.

 

[Slowgsr]

Location is a factor in ontario canada you only ground a service at the point of entry

 

[alfredeneuman]

You need both a 4 wire feeder and 2 ground rods for a detached structure.
(Unless you PROVE that 1 ground rod would measure less than 25 ohms to ground.)

The ground rod(s) should be connected to the ground bar only.
The neutral must not be bonded to ground.

 

[CNGsaves]

OP . . . to get best advice . . . Update GJ Profile with City / State / Country.

Also, GJ Sparkies can give you even BETTER advice if you provide PIC's. Like PIC of your main panel . . . AND . . . PIC of your subpanel. Provide total Amps coming into main panel, and Wire used from main panel to subpanel. Provide length of wire from Main panel to Subpanel. What breaker is in main panel to feed the subpanel ?? What amps do you want / or "need" in garage at subpanel (ie what all electrical loads in garage)??

 

[wyliesdiesels]

Question...............If you have 4 wires from the main panel, what is the symptom or problem with no ground rod at the remote panel ???

4 wires = 2 power, neutral and ground

The purpose of ground rods is to ground lightening, limit the voltage to ground potential, among other things.

People often confused grounding electrodes and EGCs/ground wires.

Heres a good article to read to help u understand the differences:

http://www.electriciantalk.com/articles/the-confusion-of-the-term-grounding/

Location is a factor in ontario canada you only ground a service at the point of entry

Ive never understood Canada's logic with that...

 

[Prometheus]

Thanks for the replies.

Is this subpanel in a detached structure? If so, you will need ground rods at the subpanel location.

Attached garage, sorry, forgot to mention that in my original post.


Not that it really matters, but I live in Michigan. It's a 55 foot run of AL SER 2-2-2-4 going from a 125 amp main panel with a 50 amp breaker to the subpanel with just main lugs in the garage. Yes, I could breaker it at a 70 amp, but I already have the 50 amp breaker from an old (removed) circuit and I don't think I will be running anything big enough to draw more than 50 amps. Also, main panel only has one bus bar.

 

[wyliesdiesels]

Thanks for the replies.



Attached garage, sorry, forgot to mention that in my original post.


Not that it really matters, but I live in Michigan. It's a 55 foot run of AL SER 2-2-2-4 going from a 125 amp main panel with a 50 amp breaker to the subpanel with just main lugs in the garage. Yes, I could breaker it at a 70 amp, but I already have the 50 amp breaker from an old (removed) circuit and I don't think I will be running anything big enough to draw more than 50 amps. Also, main panel only has one bus bar.

First off #2 AL SER is good for 90a if not buried in insulation.

I assume youre referring to the neutral bus bar.

 

[Prometheus]

First off #2 AL SER is good for 90a if not buried in insulation.

I assume youre referring to the neutral bus bar.

Correct, one neutral bus bar.

And you're right, 90 amp is my max. For some reason I was stuck on the 65* column in the ampacity table instead of the 75* column. I figured if I'm doing this, I'm only pulling cable once. At least this way if I want to upgrade later all I have to do is swap the breaker.