Need help with electrical

[Daniel]

Anyone that has good knowledge of home electrical. I need help figuring out how to connect the ground wires for my shop. I have old electrical that strappes the ground to the neutral at the fuse box. don't know where to connect the ground wires for my new panel. Info I have found says the neutral and ground can only be connected (Strapped) at the main fuse box. I have photos of my panels and how I am connecting all the feeds etc. I have my ideas of how I can do this but ideas are not good enough. hope someone can help.

 

[TheHeretic]

Not sure exactly what you looking for. There should be a ground coming into the panel for graounding the old box. That just needs to be tied off to the Neutral bus. I know I just replaced the panel in my home a week ago and there is also a screw that will go through my panel to the steel casing which is grounded by the ground tap to the panel.

Now if you are replacing the panel you need to have 2 places to ground your panel to. This is a new rule in the National Electrical Code. A lot of this has to do with that may water pipes are now plastic. But, do dont think you can ground to your gas pipes.


Dean
Columbus OH

 

[Daniel]

Dean,
the screw you mention is the strapping screw. the way I understand it it connects the box itself to the ground.
at my fuse box the ground is connected to the Neutral bar. I also connected the neutral and ground for the new circuit to this. from there the wires run to a small sub panel that has only a double pole 50 amp breaker. there is no ground bar in this box adn I am not sure if the ground wire connects to the neutral bar here as well. (per my comment above about the ground being strapped in only one location or if I need to connect the grounds together via a seperate connector (And I have no idea what that seperate connector should be). from that double pole breaker the wires then run to my shop to anouther breaker panel. again I am not sure how to connect teh ground at this panel either. there is no ground bar in this panel. it can hold up to 8 breaker switches and feed up to 16 curcuits. (It uses some fancy breaker that a single pole breaker can feed to curcuits). anyway i ahve everything wired except the grounds. Do I still connect all grounds to the neutral bars but not use the strapping screw. or do I need to figure out a way to connect all grounds together seperatly from the neutral. basically that is my only question. if the ground wires are connected seperately I need to know how to go about that since there are no ground bars. my past experience with home electrical already had all this stuff installed. I have seen it but not paid anough attention to figure it out from scratch.

 

[ctEaglesc]

I know enough about electricity to be dangerous.
I do know the white and copper wire both connect in the panel box.If you are running EMT that would grond at the subpanel which is grounded by the main.
you could always sink another ground rod for the box outside the shop.
Like I said enough to be dangerous

 

[Daniel]

Eagle,
I have the rod for at the shop, but once again the location for connecting that ground to the box is in question. I will find the answer. and I won't move ahead until I do know the answer. sucks though, everything else is hooked up but the ground wires. two more connections and I have power to my shop with lights and everything soon after. may have the light fixtures in before I find the grounding answer[]
anyway I'm heading off to home depot for all the bits and pieces I forgot yesterday[:I] and will ask around there. if no answer there I have pro electricians at work I can ask. at any rate I will not turn on the power till I am sure I have it right. one thing I do have going for me. I know when I don't know something.

 

[btboone]

Daniel, Home Depot does have some good home electrical books. Sounds like it would be worth investing in one of those just to be sure everything's done by the book.

 

[TheHeretic]

If you have the strapping screw for the panel than if you run it into the panel like it says to thay you have the Neutral bonded to the ground. This is assuming you have grounded the box by tying it to the ground system of the home. This is usually the water pipes. This would make your Neutral and your ground tied together.

Now if this is new panel than you just need to take solid wire to some thing that is grounded. A good way if its in the garage etc is to get a solid piece of pipe and drive it in the ground behind the shop and than tie panel to the solid copper pipe. And I dont mean 2 or 3 feet. They do have these types of pips that are about 8 foot long. And they suck to drive in but it is than the grounding for the panel.


Dean

 

[Daniel]

Dean, Just came in from driving the ground rod. and I ditto your suck to drive in, we have hard clay soil just to make it all that much more fun. Anyway, thanks for helping. I got it figured out. I had to add ground bars to both boxes and have to ground the new box to the rod as well. almost everything is in now. I just have to wire up about siz outlets, one switch and the 220 outlet for my dust collector. I shoudl have power in my shop by noon tomorrow [][][8D]

 

[Daniel]

By the way bruce, I have about a half dozen small home electrical books, a huge residential wiring text book and have searched the net several times over. the problem with finding directions for this is that I am adding a grounded system to basically a non grounded one. my house wiring does not have ground wires so the fuse box is not set up to accept them. What I am doing does not seem to be covered in the how toos.

 

[bradh]

What you are doing sounds safe. The neutral line should be grounded by the hydro supplier at a local pole, but the extra ground rods ensure that your local ground is the same as theirs. Grounding both boxes ensures both boxes are at the same ground too.
Brad

Originally posted by Daniel
<br />Dean, Just came in from driving the ground rod. and I ditto your suck to drive in, we have hard clay soil just to make it all that much more fun. Anyway, thanks for helping. I got it figured out. I had to add ground bars to both boxes and have to ground the new box to the rod as well. almost everything is in now. I just have to wire up about siz outlets, one switch and the 220 outlet for my dust collector. I shoudl have power in my shop by noon tomorrow [][][8D]

 

[Daniel]

Brad,
that just about sounds like what I learned. the ground and neutral being tied together is what throws off my thinking so I had to go with the follow the pictures method. Problem is I couldn't find any pictures. My shop has now officially had power for over 10 hours now. I actually turned on the lights to put in the last two outlets. got myslef bit for the one and only time for my trouble. Thought I had the curcuit shut off at he breaker and then got a tingle while straightening the wires out. should have seen me there for a munite trying to figure out how I power getting past a shut off breaker. I had simply shut off the wrong breaker. other than that it is all good. didn't even cut my thumb with the box knife stripping all those #6 wires (not much anyway). just a note of intrest. this will be the first time ever that I can just walk up to any piece of my shop equipment and turn it on without having to swap an extension cord from somewhere else. I will have to relearn how to turn a pen. I had to resist the urge to turn everything on at once []
by the way. for all of those that where concerned in my last posts about my fuse box. the power to my shop routes around the box so I will not be burning down my house. and in case anyone ever needs to know. you can fit 8 #6 conductors in a 1" conduit... I have pictures to prove it.

 

[TheHeretic]

Well if you put 8 #6 conducters in a 1 inch pipe I would suggest that you do it again in 1 1/2" pipe. There are formularys for putting that many wires in the conduit. It has to do with air flow around the pipes. Just thinking out load now.

Glad everything worked for ya!!


Dean

 

[Daniel]

Dean, It is a very short run. Like three inches where I took the wires from one box to anouther and then back again. and there is actually still air space. but I was shocked that it would work. before I started I was wondering if 4 where going to fit. I've seen some conduit packed pretty full. the type of wire makes a difference also, but i've seen some two and two and a half inch conduit so full nothing can be moved. I think the same thing when I see them. doesn't it have to pass off the heat some how? that sort of wiring is way beyond anything I ever want to do though.

 

[tcastel]

When you install a sub panel you are required to have both a ground bar and a neutral bar. The screw you are talking about that goes through the neutral bar is called a bonding screw and is only instaled in the main panel, NEVER in the sub panel.The cable from the main panel to the sub panel must be a 4 wire cable. The white wire being the neutral and the green or bare wire (depending on the cable you use). You should <u>NEVER</u> drive a ground wire and attach it to a sub panel. National Electrical Code requires that there should only be one Ground in any service. The reason for this is that because of the distance between the rods and the earth conditions surronding the rods there can develop a difference in potential between the two grounds. This difference in potential can be transfered to the metal parts of the your equipement and cause a shock problem. This is a classic example of when I first got into Electrical and people would complain about getting a shock when they touched their kitchen faucet. The cause of the problem was always because the copper piping for the water system had not been connected to the grounding system of the panel(which is required by Code). What they were actually feeling was the difference in potential between the ground rod for the panel and the great ground from the copper pipe buried in the ground.

 

[jeff]

Originally posted by tcastel
<br />... You should <u>NEVER</u> drive a ground wire and attach it to a sub panel. National Electrical Code requires that there should only be one Ground in any service.

I believe that this is only true when the subpanel is in the same building as the main panel. True, you should never rebond the neutral and ground, but I believe that the NEC requires a grounding electrode at the subpanel when it is located in a separate building with no metallic connection to the building where the service originates. I'll check the code book when I get to work...

Edit: 2002 NEC article 250.32 would appear to confirm my statement. In fact, regardless of other metallic connections between buildings, the NEC requires a ground rod at the second building for lightning protection. (See 250.32(a), 250.32(b)(1), and 250.32(b)(2))

 

[Daniel]

Hi Ya Jeff, I was really hoping you would chime in here. good to see your thinking is supporting me. I actually brought up the whole two ground rod thing to people I talked to face to face. here is what I was told. My house is not grounded with that huge copper rod. it is grounded to the water pipes. this is not considered good enough anymore (Basically) and because I was going 65 feet to the new building they wanted the new box having it's own ground rod. this in effect does have my house connected to a ground rod but not close enough for code which says the ground has to be with in 6 feet of the fuse box. since I didn't change anything about my old box I didn't have to upgrade it but all the new stuff does have to meet todays codes. jeez and I was wondering why I was getting so jumpy the other day. I do plumbing like a snap and it is pretty complicated, but nothing like electrical. Hope I can stick with just putting in outlets and replacing light fixtures in the future. this adding new service stuff is for the pros.

 

[Daniel]

Oh by the way, it was the rebonding thing that had be baffled. I didn't care about the little green screw. I still figured that adding all the bare ground wires and the neutrals to the same bar was rebonding anyway. with there being no ground bar in the boxes, I was pretty stumped just what to do. found out you can actuall add bars to the boxes so that was the way I went. keeps all the ground wires and neutral wires away from each other so everybody can get along. yet has everything grounded like the authorities want it to be.

 

[Daniel]

Tony, Just so you know I am not ignoring what you said. I will watch for the conditions you say can develope. here is my thinking on it with all the bits and pieces I have in my head.
Todays code requires that a ground rod be driven 8 feet into the ground,. even just few years ago I think it was 6 feet, so the truth is they still don't know what is good enough. anyway. my house is grounded to the water pipes but they are only about 2 feet in the ground. and run all over tarnation. my thinking says at worst I grounded my house to a single point that is more in line with todays code than what it has had in the past. the ground and neutral are bonded only at the point they have been connected in the past. although the new wiring also connects them at this point they are not connected at any other point. everything I read or heard mentioned concern about the neutral and ground wires being connected at only one point. this is the first time I have heard anything concerning there being more than one ground rod. in fact everything I read said the new box must have it's own ground rod due to the distance from the original box.
My thinking was in agreement with you until I started checking around. originally I thought I woudl jsut connect bare wires to a bar and it woudl all run back to the fuse box. then it all started getting confusing with the new box needing a ground as well. anyway my thinking was like yours and I kept getting info that said I was wrong, I couldn't understand why and am still not sure I do, What I do know is that the new ground rod is needed. and I had to get everything connected to it without connecting the bare wires and the white wires. funny though I would think the hard part should be what to do with all the wires that have electricity in them. those I had no question what to do with. but that stupid bare wire that you can chew on all day long is the one that gives me fits.
from what I can tell the real issue is if the ground and neutral are connected at more than one point.