Main Electric Panel Help

Redrum Ninja · 10-21-2011, 08:39 PM

Hey all, first post here on the forums.

I have done my share of electrical wiring in my days, installed outlets, recessed lighting and wired a shed. I was wondering if someone could help me out or correct me to see if my anatomy of the main electric panel.

Keeping it simple, here's what I am getting at:

I know I have 150 amp service which is coming in through a heavy grey cable that had 2 big black wires and then a shield-like wire which is the neutral/ground. I have read and know that the white wires and the bare ground wires connect to one bar in the main panel only. So you have the 2 black wires connecting to the two top lugs and then the shield-like wire connecting to the neutral lug and that's it right? Of course a ground wire coming from the water meter or ground rod etc would then connect to one of the terminals on the neutral bar right? That is where my big question is. About the neutral/ground.

In a main electric panel with a main breaker (150 amps in this case) would this be equivalent to the setup described above and be alright with code etc?

2 black wires entering connecting to the hot lugs at the top.
1 white/shield wire entering connecting to the neutral lug
1 green/bare wire (that has entered the panel coming from the water meter, grounding rod etc.) entering and NOT connecting to the neutral bar, but instead a seperate ground bar that had been screwed and bonded to the inside of the panel, and then have a bonding wire that runs from one of the neutral terminals on the neutral bar to one of the ground terminals on the ground bar? Or would this not be necassary? It seems to me at this point that the only reason you would do what I just mentioned is purely for organization or ground wires on one bar and neutrals on the other, but I am unsure. I'm curious to understand more about the whole system of grounding and the neutral in the main panel.

I do know that the neutral and ground are seperate in a sub panel and that this information applies only to main breaker panels.

Also is running a ground wire from the main panel to the water meter enough to satisfy most codes? or would having a grounding rod or two and then the same wire running to the water meter (with no splices) be better?

Thanks!

Sfeyelectric · 10-21-2011, 08:52 PM

Quote:

Originally Posted by Redrum Ninja

Hey all, first post here on the forums.

I have done my share of electrical wiring in my days, installed outlets, recessed lighting and wired a shed. I was wondering if someone could help me out or correct me to see if my anatomy of the main electric panel.

Keeping it simple, here's what I am getting at:

I know I have 150 amp service which is coming in through a heavy grey cable that had 2 big black wires and then a shield-like wire which is the neutral/ground. I have read and know that the white wires and the bare ground wires connect to one bar in the main panel only. So you have the 2 black wires connecting to the two top lugs and then the shield-like wire connecting to the neutral lug and that's it right? Of course a ground wire coming from the water meter or ground rod etc would then connect to one of the terminals on the neutral bar right? That is where my big question is. About the neutral/ground.

In a main electric panel with a main breaker (150 amps in this case) would this be equivalent to the setup described above and be alright with code etc?

2 black wires entering connecting to the hot lugs at the top.
1 white/shield wire entering connecting to the neutral lug
1 green/bare wire (that has entered the panel coming from the water meter, grounding rod etc.) entering and NOT connecting to the neutral bar, but instead a seperate ground bar that had been screwed and bonded to the inside of the panel, and then have a bonding wire that runs from one of the neutral terminals on the neutral bar to one of the ground terminals on the ground bar? Or would this not be necassary? It seems to me at this point that the only reason you would do what I just mentioned is purely for organization or ground wires on one bar and neutrals on the other, but I am unsure. I'm curious to understand more about the whole system of grounding and the neutral in the main panel.

I do know that the neutral and ground are seperate in a sub panel and that this information applies only to main breaker panels.

Also is running a ground wire from the main panel to the water meter enough to satisfy most codes? or would having a grounding rod or two and then the same wire running to the water meter (with no splices) be better?

Thanks!

Here you would need the ground bars; However, it is a seperate copper line going to the ground bars than the water meter.

Billy_Bob · 10-21-2011, 08:55 PM

It would be helpful if you could say what work you intend to do or if you are just curious and not going to do any work on the main panel.

But if for example you are going to install a new main panel somewhere else or change out your existing main panel at the existing location, then it would be helpful to know that...

Redrum Ninja · 10-21-2011, 08:58 PM

Quote:

Originally Posted by Billy_Bob

It would be helpful if you could say what work you intend to do or if you are just curious and not going to do any work on the main panel.

But if for example you are going to install a new main panel somewhere else or change out your existing main panel at the existing location, then it would be helpful to know that...

I was thinking about changing my own panel, but not right away. At the moment I am trying to gather information.

mpoulton · 10-22-2011, 12:01 AM

Comments in red.

Quote:

Originally Posted by Redrum Ninja

Hey all, first post here on the forums.

I have done my share of electrical wiring in my days, installed outlets, recessed lighting and wired a shed. I was wondering if someone could help me out or correct me to see if my anatomy of the main electric panel.

Keeping it simple, here's what I am getting at:

I know I have 150 amp service which is coming in through a heavy grey cable that had 2 big black wires and then a shield-like wire which is the neutral/ground. I have read and know that the white wires and the bare ground wires connect to one bar in the main panel only. So you have the 2 black wires connecting to the two top lugs and then the shield-like wire connecting to the neutral lug and that's it right? Of course a ground wire coming from the water meter or ground rod etc would then connect to one of the terminals on the neutral bar right? That is where my big question is. About the neutral/ground.

All of that sounds good.

In a main electric panel with a main breaker (150 amps in this case) would this be equivalent to the setup described above and be alright with code etc?

2 black wires entering connecting to the hot lugs at the top.
1 white/shield wire entering connecting to the neutral lug
1 green/bare wire (that has entered the panel coming from the water meter, grounding rod etc.) entering and NOT connecting to the neutral bar, but instead a seperate ground bar that had been screwed and bonded to the inside of the panel, and then have a bonding wire that runs from one of the neutral terminals on the neutral bar to one of the ground terminals on the ground bar? Or would this not be necassary?

This is usually allowed. The jumper between busses is probably not required, but that depends on the manufacturer's instructions. When you install an auxiliary ground bus kit, it will include a jumper or tell you if one is required. Many of them just screw to the panel chassis.

It seems to me at this point that the only reason you would do what I just mentioned is purely for organization or ground wires on one bar and neutrals on the other, but I am unsure. I'm curious to understand more about the whole system of grounding and the neutral in the main panel.

That's true. There's no reason to do it unless you've run out of space on the factory ground/neutral bus.

I do know that the neutral and ground are seperate in a sub panel and that this information applies only to main breaker panels.

Yes. In a subpanel, you would remove the bonding jumper on the factory ground/neutral bus to isolate it from the chassis, and then install a separate grounding bus kit in the panel.

Also is running a ground wire from the main panel to the water meter enough to satisfy most codes? or would having a grounding rod or two and then the same wire running to the water meter (with no splices) be better?

Two ground rods are usually required. You can get away with one, but only if you can prove that it's impedance is low enough. You can't. So you need two. The bonding wire to the water line is also required, and serves an entirely different purpose. It is intended not as a grounding electrode connection, but to ensure that the plumbing cannot become energized. Thus, you need it even if the incoming water service is plastic.

Thanks!

brric · 10-22-2011, 08:20 AM

Quote:

Originally Posted by mpoulton

Comments in red.

The conductor from the panel to the metallic water piping forms a grounding electrode, which is far more effective than any two ground rods.

Billy_Bob · 10-22-2011, 09:12 AM

Quote:

Originally Posted by Redrum Ninja

I was thinking about changing my own panel, but not right away. At the moment I am trying to gather information.

Ok, then there are some additional things you would be wise to do...

You have the option of upgrading your electric service to say 200 amps. If you plan on doing any room additions, getting an electric kiln, buying an electric car, or doing anything else which might use more electricity, then you may want to consider that. Otherwise 150 amps might be just fine.

And when you replace your panel, you may be required to bring everything (electric service related) up to code...

With that said, my electric company has a document called "Electric Service Requirements". That says the way everything must be [now] for electric service overhead wires, wire height, wires running over roofs/driveways, roads... Where a panel can and can not be located, and on and on.

Anyway it could be that something was done in the past which is not now allowed. For example the electric service wire might be going over a roof at a low height and that might not be allowed now. And you might need to raise that to bring things up to code...

So best to get a copy of that or whatever your electric company has and see if there might be anything you will need to change.

Also if you want to increase the amperage on your service, you need to call the electric company and ask if you can do this.

You also may want to have the electric company come out and look at your electric service. See if anything will need to be changed to bring it up to code. (The electric company guy has a handy dandy measuring stick to check the height of overhead wires.) Then a good time to ask questions about removing power so you can safely do your work.

Then also take pictures of your entire electric service, wires coming into house, meter, main panel, grounding, near and far away pictures. Then go to your local electrical inspectors office, ask to speak with an inspector, then show him the pictures.

Tell him you are going the change out the panel. Ask if you will need to upgrade/change anything. Discuss every exact detail of grounding including ground wire sizes, if run in conduit, ground rods and their sizes, bonding to cold water pipe, etc.

Do the above, then you will not have any "surprises"!

Also it is common for aluminum wire to be used for the main service conductors. You need to apply anti-oxidation goop to these wires before connecting them to the panel. (Sold in the electric department.)

Main high amperage electrical connections *must* have the lugs tightened to a certain tightness, otherwise the connection can heat up. The panel instructions will say to tighten the lug nuts to a certain "inch pound" tightness. Use a torque wrench for this.

12 inch pounds = 1 foot pound. Automotive torque wrenches may not "click" below a certain foot pounds and may cause you to over tighten it. I prefer one of those cheap automotive torque wrenches with the needle indicator rather than the "click" kind. Then you can see low inch pound readings. And you can get "hex" (or flat blade screwdriver) sockets at an automotive store or tool store. Take a lug nut with you to get the right size.

Also torque wrenches can keep certain "king kong" men from tightening things too tight and stripping the threads. I have a friend who does this, so I make him use a torque wrench so he will not wreck things!

In my area, you get an electrical permit to do this work, then the electrical inspector comes out and looks at everything, then places a sticker on the panel saying it passed inspection. THEN the electric company will connect the electricity.

Redrum Ninja · 10-22-2011, 11:28 AM

Thanks everyone, I have been looking around at different main breaker panels and have noticed the Homeline series seems to be the best value overall and I know that I had an electrician install one for my second floor renovation as a sub panel and that seems to be what I might go for. I have noticed in some pictures that the neutral bus bars are at the top of the panel. Looks to be about 7 screws on one piece of the bar and then another 7 screws, then the main breaker, and the same thing on the other side. I don't really like the way it is set up. Is there any way to move the neutral bars so that they are going down one side of the panel? Here is a pic:

http://www.remodeling.hw.net/Images/...m17-231623.jpg

Is this on the Homeline series of panels? Or is it on the QO series only? Someone clear this up?

Why in the picture above are the neutral bars different? I'd much rather have something like this:

http://www.qccomputer.com/ebay/100A2...oadCenter3.gif

brric · 10-22-2011, 11:53 AM

Quote:

Originally Posted by Redrum Ninja

Thanks everyone, I have been looking around at different main breaker panels and have noticed the Homeline series seems to be the best value overall and I know that I had an electrician install one for my second floor renovation as a sub panel and that seems to be what I might go for. I have noticed in some pictures that the neutral bus bars are at the top of the panel. Looks to be about 7 screws on one piece of the bar and then another 7 screws, then the main breaker, and the same thing on the other side. I don't really like the way it is set up. Is there any way to move the neutral bars so that they are going down one side of the panel? Here is a pic:

http://www.remodeling.hw.net/Images/...m17-231623.jpg

Is this on the Homeline series of panels? Or is it on the QO series only? Someone clear this up?

Why in the picture above are the neutral bars different? I'd much rather have something like this:

http://www.qccomputer.com/ebay/100A2...oadCenter3.gif

That is one of the differences between SQ D QO and Homeline load centers.

mpoulton · 10-22-2011, 04:05 PM

Quote:

Originally Posted by brric

The conductor from the panel to the metallic water piping forms a grounding electrode, which is far more effective than any two ground rods.

If the incoming water line is metal. If it's plastic, then the bond to the building's plumbing is still required, but it's not effective as a grounding electrode.

brric · 10-22-2011, 05:54 PM

Quote:

Originally Posted by mpoulton

If the incoming water line is metal. If it's plastic, then the bond to the building's plumbing is still required, but it's not effective as a grounding electrode.

That is correct. The incoming piping must be metallic(which should be obvious but oftentimes is not) to be used as a grounding electrode, and a bond is only required if the interior pipiing is metallic(also should be obvious).

Billy_Bob · 10-22-2011, 06:26 PM

...and it is common for the underground portion of the metal pipe to spring a leak, then be replaced with plastic.

brric · 10-22-2011, 08:01 PM

Quote:

Originally Posted by Billy_Bob

...and it is common for the underground portion of the metal pipe to spring a leak, then be replaced with plastic.

Just how common is that?

Billy_Bob · 10-22-2011, 08:28 PM

Quote:

Originally Posted by brric

Just how common is that?

Five times within a few weeks as noticed by inspectors in the City of Bellevue, WA.

According to the following...
http://www.kirklandwa.gov/depart/Fir...nd_H2O_MIX.htm