Wiring a detached garage

[Mohrenberg]

Hello everybody.

I know this has probably been answered before a million times but I'm looking for some clarification on a few things
I just finished building a 24 by 40 pole barn. I'm getting ready to add electrical to it. I've read a lot of threads on here asking about installing grounding rods and whether or not the neutral and ground should be connected at the sub panel.
One thing I'm not completely clear on is when people say main panel or main breaker are they referring to the breaker panel inside their house or the one on the light pole at the meter?
At my place electricity goes from the meter on the pole to my house, and the garage is in the opposite direction so I will be running electricity from the pole at the meter (in the breaker box below it) to my garage.

My garage is all metal and I live in a very flat open area it's a lot of Pastor so I want to make sure grounding rods are in the right places in case of a lightning strike
I would also prefer not to die while using equipment in my garage so I would like to make sure that I get the neutral and ground wires hooked up correctly in the panel

I will be doing all the wiring myself but I will be having someone come out and inspect everything before I hook it up to the electric Pole

 

[Aceman]

Post pics of your panels so we can see what you're working with. Covers open or off.

 

[Mohrenberg]

Sure will, tomorrow morning when I get home from work.

Btw, I'm Matthew. I'm 31, and a Paramedic by trade.

 

[CNGsaves]

What country are you in ???

UPDATE GJ Profile with a Location to get best advice.

 

[Mohrenberg]

Oh, sorry.
I live in missouri.

 

[wyliesdiesels]

Is there a main breaker below the meter?

How will u be tying into the meter?

If you are connecting to a breaker, then u need 4 wire feeder.

And u always need ground rods for detached structures

 

[Mohrenberg]

Here is the house, with the pole on the right.


And to the right some more is the garage. So the house and garage are in opposite directions in relation to the pole.


The meter has a breaker box on it.
I plan to add a breaker in this box, and run it to a sub panel inside the garage.


The back of my house where electric goes in.


This is the basement where the electric comes in. The brown panel is the main one for the house, and the grey one is a sub panel that is coming off the brown one.







how to take a screenshot on a pc

I didn't get the front of the meter panel taken off to see inside, I was in a bit of a rush. I'll be back home in a few hours and I can get a picture inside of it.

So, I guess what I'm trying to figure out right now is whether my neutral and ground bus should be connected, or seperate.

 

[dave89iroc]

technically, both the house panel and the future garage panels are sub panels off the main breaker/s at the meter

 

[theoldwizard1]

In most US homes (urban and suburban) the meter is on the back of the house and you are allowed to run a "service entrance" cable a limited distance to inside the house. This is the then referred to as the "main" panel/breaker box. (The proper electrical industry term is "load center".)

At my place electricity goes from the meter on the pole to my house, and the garage is in the opposite direction so I will be running electricity from the pole at the meter (in the breaker box below it) to my garage.

You do know you just contradicted yourself !

The wire from the meter does NOT go to your house, it goes to what is typically referred to as a "disconnect". Some disconnect have space for one set of breakers/switches, some have room for more. If you have room for another set of breakers, this would be a good place to hook up your garage.

My garage is all metal and I live in a very flat open area it's a lot of Pastor so I want to make sure grounding rods are in the right places in case of a lightning strike. I would also prefer not to die while using equipment in my garage so I would like to make sure that I get the neutral and ground wires hooked up correctly in the panel

If you are concerned about lightening, then install lightening rods and separate grounding for them.

I will be doing all the wiring myself but I will be having someone come out and inspect everything before I hook it up to the electric Pole

If that is NOT an official inspector, make certain they are up to date on the NEC.

 

[theoldwizard1]

I plan to add a breaker in this box, and run it to a sub panel inside the garage.

Again, that would be referred to as a disconnect. When the meter "pan" and disconnect are one, they are typically called a meter-disconnect "combo".

Adding another set of breakers here is appropriate. Remove the cover off of the bottom half and take a picture of what is inside. Who is the manufacturer and what is the model number of that combo ?


IANALE, but I believe the present electrical code would require ground rods at the pole, a 4 wire service to the new building and more ground rods. Your house is "grandfathered" so you do not have to change anything there.

 

[Aceman]

So, I guess what I'm trying to figure out right now is whether my neutral and ground bus should be connected, or seperate.

I don't even know where to start with your house panel. It is an absolute wreck.

1. How many wires from the metermain on the pole come into the main panel in your home?

2. We usually ground the main house panel a few different ways. We will take a ground wire from the panel and run down to a piece of rebar from the footing that we attach a clamp to. Or we run over to a metallic water pipe coming out of the ground that we attach a clamp to. Or we run outside to some ground rods that are driven in the ground. Do you see any ground wires leaving the panel going to any of these?

3. The buss bar that all the neutrals and grounds land on, is it screwed directly into the back of the panel or is it on plastic standoffs? If it's on plastic standoffs, do you see a green screw going through the buss bar connecting it to the back of the panel?

With the questions out of the way, here's the problems I see:

1. You can't have plumbing pipes hanging in front of the panel. An inspector would shoot that down right out of the gate.
2. Neutrals and grounds can't share the same hole in the neutral buss. Your panel needs another ground buss added with some of the ground wires moved over to it to make room on the existing buss.
3. White wires on breakers. They need to be taped black or some other color than white/gray/green if they land on a breaker.
4. Cord is not a replacement for permanent wiring. I can see the green ground wires from 3 cords in your panel. I would be curious why there is cord ran to your panel. In the time I've been an electrician, I've never ran cord out of a residential loadcenter.

Posting pics of the metermain on the pole with the cover removed would be a good idea.

 

[Mohrenberg]

The house wiring is a separate nightmare all together. I'll probably have to hire an electrician to come in and redo the panels. I have minimal knowledge and it's crazy how some of it was wired. I live out in the country so there are no permits or inspections required, which shows on this house. When they remodeled the home someone wired it up who didn't do their research. All the 3way switched were wired wrong and required the switches to be in correct positions for the lights to come on. I also had gfci outlets wired backwards that would trip if anything was plugged into them.

I may replace and rewire the panels myself too after the garage is done, so I could disconnect the house at the pole and run lighting into the utility room from the garage and spend a day cleaning it up.

I'll get the info on the disconnect/meter and get a picture with the panel off.

 

[Mohrenberg]

The main question i have is whether or not my neutral and ground bus bars should be isolated or connected in my garage panel.

I seem to be getting conflicted info.
One thing I read suggested I should run 3 conductors (2 hots and 1 neutral) from the meter disconnect, and then have my bare ground from appliance and outlet running to an isolated bus bar that runs to the grounding rods outside.

 

[marklc]

The main question i have is whether or not my neutral and ground bus bars should be isolated or connected in my garage panel.

I seem to be getting conflicted info.
One thing I read suggested I should run 3 conductors (2 hots and 1 neutral) from the meter disconnect, and then have my bare ground from appliance and outlet running to an isolated bus bar that runs to the grounding rods outside.

Where I am at in PA we would run a 4 wire subfeed cable to your garage and have the neutral and ground separate in that subpanel. Don't use the green bonding screw. We are not required to add more ground rods to a sub panel here.

 

[pattenp]

Where I am at in PA we would run a 4 wire subfeed cable to your garage and have the neutral and ground separate in that subpanel. Don't use the green bonding screw. We are not required to add more ground rods to a sub panel here.

Does not Pennsylvania have a Uniform Construction Code that is to be followed state wide? I believe the electrical part requires that all electrical components equipment and systems in buildings and structures covered by the IBC comply with the requirements of the National Electric Code. So it appears you would be required to have an electrode grounding system at an outbuilding. Though additional ground rods would not be required if the subpanel was in the same building as the main service panel.

 

[Smoker]

Where I live they required a Ufer ground when I poured the slab. It and the ground from the 4 wire feeder cable are bonded together and to the ground lug on the sub panel. The neutral is NOT required to be connected to ground with the green screw. In lieu of a ufer I think additional ground rods would have been required. But regardless the city wouldn't allow reliance on the ground wire from the main panel alone.

 

[wyliesdiesels]

The main question i have is whether or not my neutral and ground bus bars should be isolated or connected in my garage panel.

I seem to be getting conflicted info.
One thing I read suggested I should run 3 conductors (2 hots and 1 neutral) from the meter disconnect, and then have my bare ground from appliance and outlet running to an isolated bus bar that runs to the grounding rods outside.

I see u havent gotten all your questions answered.

First off, whether your existing garage should have an isolated neutral bar or not depends on when it was wired.

Prior to 2008, code allowed 3-wire feeds to detached structures. The neutrals and EGCs/grounds would go to the same bar which is bonded to the panel enclosure.

After 2008, the branch feeder would need to be 4-wire with separate neutral and ground bars, and the neutral bar needing to be isolated.

Grounding electrodes are required regardless of type of feeder. And 2 are required unless u can prove 25ohms or less of resistance to earth.

The new branch feeder to the pole barn needs to be 4-wire. The ground should NOT be isolated from the panel. Whoever said that confused the neutral bar(which should be isolated) with the ground bar.

U always want the ground bar bonded to the panel. The grounding electrodes will connect to this bar.

The only time u can run a 3-wire feeder to a detached structure is if it comes straight from the meter/not a disconnect. U have a disconnect below your meter.

Here is a pic to help u:

Where I live they required a Ufer ground when I poured the slab. It and the ground from the 4 wire feeder cable are bonded together and to the ground lug on the sub panel. The neutral <font>color='red'should NOT </font> be connected to ground with the green screw. In lieu of a ufer I think additional ground rods would have been required. But regardless the city wouldn't allow reliance on the ground wire from the main panel alone.

Fixed it for ya.

And you are confusing things. The ground wire that goes back to the main panel is a different animal and serves a completely different purpose.

Grounding electrodes main purpose is to ground lightning. The ground wire that goes back to the main is for fault current.

Read this:

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

 

[Mohrenberg]

This is the inside of the meter/disconnect.
I want to add a 100A breaker to the slot on the top left and run it to my pole barn.

That bare copper wire runs out of the back of the panel and attaches to the pole and seems to be buried with the pole. It also goes up to the top of the pole...


So do I need to run 4 wires? If so, why? If the ground and neutral are connected here, what the point of running two different wires that are connected to the same thing?

That's also brings up the question, if I need to run 4 wires to my garage, why does my house only have 3?

 

[Mohrenberg]

I see u havent gotten all your questions answered.

First off, whether your existing garage should have an isolated neutral bar or not depends on when it was wired.

Prior to 2008, code allowed 3-wire feeds to detached structures. The neutrals and EGCs/grounds would go to the same bar which is bonded to the panel enclosure.

After 2008, the branch feeder would need to be 4-wire with separate neutral and ground bars, and the neutral bar needing to be isolated.

Grounding electrodes are required regardless of type of feeder. And 2 are required unless u can prove 25ohms or less of resistance to earth.

The new branch feeder to the pole barn needs to be 4-wire. The ground should NOT be isolated from the panel. Whoever said that confused the neutral bar(which should be isolated) with the ground bar.

U always want the ground bar bonded to the panel. The grounding electrodes will connect to this bar.

The only time u can run a 3-wire feeder to a detached structure is if it comes straight from the meter/not a disconnect. U have a disconnect below your meter.

Here is a pic to help u:

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Fixed it for ya.

And you are confusing things. The ground wire that goes back to the main panel is a different animal and serves a completely different purpose.

Grounding electrodes main purpose is to ground lightning. The ground wire that goes back to the main is for fault current.

Read this:

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

Thanks for the info!
I think I've got it figured out...even if it doesn't seem to make total sense.

So I'll run a 4 wire cable (hot,hot,neutral, ground) to the garage.
The neutral and ground bus bars will be isolated from each other. The ground bus bar will be bonded to the metal panel.
All my bare copper wires from recepticles will lead to my ground bus bar, and neutrals to neutral bus bar.
I'll also have a copper wire lead to two 8 foot grounding rods 6 foot apart outside.

Sound about right?

 

[wyliesdiesels]

This is the inside of the meter/disconnect.
I want to add a 100A breaker to the slot on the top left and run it to my pole barn.

That bare copper wire runs out of the back of the panel and attaches to the pole and seems to be buried with the pole. It also goes up to the top of the pole...


So do I need to run 4 wires? If so, why? If the ground and neutral are connected here, what the point of running two different wires that are connected to the same thing?

That's also brings up the question, if I need to run 4 wires to my garage, why does my house only have 3?

That bare cooper wire runs to a ground at the pole as well as a grounding terminal up top. Its for lightning suppression.

I explained above why your house has 3 wires and how code now requires 4-wire for detached structures. Your house is grandfathered in.

And BTW i forgot to mention in my last comment that 3-wire to a detached structure was only allowed IF there were no parallel metallic pathways between the 2 structures.

The reason why 3-wire is no longer allowed u ask? Its because IF the neutral ever developed a bad connection, u could have neutral return currents flowing on grounded bonded metal objects such as building steal and conduit since a 3-wire feeder has a bonded neutral bar in the subpanel. Its rare but it can happen.

And in response to your question about main service panels in your OP, the main service panel or main disconnect is the first disconnect after your meter. Since theres a breaker/disconnect at the meter, your house panel is a subpanel.

 

[wyliesdiesels]

Thanks for the info!
I think I've got it figured out...even if it doesn't seem to make total sense.

So I'll run a 4 wire cable (hot,hot,neutral, ground) to the garage.
The neutral and ground bus bars will be isolated from each other. The ground bus bar will be bonded to the metal panel.
All my bare copper wires from recepticles will lead to my ground bus bar, and neutrals to neutral bus bar.
I'll also have a copper wire lead to two 8 foot grounding rods 6 foot apart outside.

Sound about right?

Correct.

Neutral bar should be on plastic standoffs and u may need to remove a green bonding screw from this bar.

U also may need to purchase a separate ground bar kit.