Need some help with grounding / neutral / bonding etc.

[BBQ&Love]

Context: I just installed a new permanent service pole beside the old one since the old one is about to snap off from rot. I upgraded from a 60 amp service to a 200 amp service. I have a mobile home and a shop, each with it's own service panel, and with existing wiring running to the mobile home. There is an existing 1 1/4" conduit to the shop. All wiring is copper. I am not concerned about meeting inspection but I am concerned about it being safe. At one time I knew all this like the back of my hand but after frying too many brain cells (illness) I am a bit hazy on grounding / neutral / bonding issues.

1. The wiring to the mobile home is (2) #6 wires with a #10 bare wire. The conduit to the mobile home is 1" PVC and I don't know if it goes the whole way. (Eventually the wiring to the mobile home will be upgraded. Probably when it gets moved out and I build a 16x52 portable cabin in its place.)

2. The wiring to the shop will be (3) #4 wires. (I have the wiring.) The conduit to the shop is 1 1/4" PVC. The shop has a 100 amp service panel.

3. I have 3 ground rods on hand. The mobile home panel has no ground rod. The panel at the pole only had a #12 wire running into the ground 4' for the ground. I put one of my ground rods in at the new pole and connected it to the new service panel on the pole.

4. To be clear, each building has its own service panel. The panel at the pole is basically a disconnect. I am not feeding any sub-panels off of it. Only 2 service panels.

5. There will be one 20 amp circuit at the pole service panel. It will feed a GFCI outlet right on the pole.

My Questions:

1. Can I avoid the fourth wire to the shop if I put a ground rod in at the shop, tie the ground rod to the grounds of the shop wiring at the ground bar, and tie the third leg to the neutrals of the shop wiring at the neutral bar?

2. Do I need to bond the neutral bar to the ground bar at the shop service panel? (It is my understanding that I do.)

3. What do I do with the mobile home? Can I put a ground rod in there and tie it to the grounds in the service panel?

4. Do I need to bond the neutral bar to the ground bar at the mobile home service panel? (It is my understanding that I do.)

5. Do I need to bond the neutral bar to the ground bar at the pole home service panel?

Thanks for your assistance.

 

[oleguy]

neutral and ground bond together at 200 amp panel.then shop and mobilehome are treated as sub panels.you need 4 wires to shop and mobile.2-hots 1 neutral and a ground.ground rod at shop.so neutral and ground are bonded at first disconnect.

 

[VHF]

With 3 wires feeding a building, the neutral and ground are bonded together at that building's main panel. With 4 wires feeding a building (which is requierd for new installations), neutral and ground are kept separated.

In either case, each building should have 2 ground rods 6' apart.

Because you have a 120V outlet at the pole, it also needs to be treated as a "building" with ground and neutral bonded and 2 ground rods.

It would be good if you can eventualy end up with 4-wire feeds to each building. Note that you can use a smaller ground wire. I think a #8 ground would be sufficent in conjunction with your (3) #4 wires feeding the shop (which I think is good for 85A--OK to use your 100A panel in the shop, but feed it from an 80A or 90A breaker at the pole.)

 

[Charles (in GA)]

I am not concerned about meeting inspection but I am concerned about it being safe. At one time I knew all this like the back of my hand but after frying too many brain cells (illness) I am a bit hazy on grounding / neutral / bonding issues.

I understand your concerns here, but it is certainly best for many reasons to stick with or close to code, even if not being inspected. Some day you may sell, and a whacked up electrical could easily queer a deal and leave you spending money just to sell the place (so why not spend it now while you have the luxury of time on your hands and get it right to begin with and shop for the best prices).

Good info so far, two rods at each location, four wires to each location, the box at your pole is your main service, beyond that it is a sub-feed.

Realize that ground wire smaller than a 6 solid has to be physically protected (again by code) and its well worth just using a 6 even if you could get by with smaller, saves having to put it in conduit or hide it to be proper.

 

[Norcal]

W/ a mobile home, unless it's 120V only a 4-wire feed is a must, the bonding of the neut. & grounding electrode conductor has to be done at the service equipment at the pole, it is not safe to do it at the MH/ trailer panel. There is more to the OP's issues but that is all from me, ATM.

 

[BBQ&Love]

W/ a mobile home, unless it's 120V only a 4-wire feed is a must, the bonding of the neut. & grounding electrode conductor has to be done at the service equipment at the pole, it is not safe to do it at the MH/ trailer panel. There is more to the OP's issues but that is all from me, ATM.

Upgrading the wiring that has been here since 1984 is not an option at this point. So I am trying to do the best I can with what I have to work with at this point.

 

[BBQ&Love]

I understand your concerns here, but it is certainly best for many reasons to stick with or close to code, even if not being inspected. Some day you may sell, and a whacked up electrical could easily queer a deal and leave you spending money just to sell the place (so why not spend it now while you have the luxury of time on your hands and get it right to begin with and shop for the best prices).

Good info so far, two rods at each location, four wires to each location, the box at your pole is your main service, beyond that it is a sub-feed.

Realize that ground wire smaller than a 6 solid has to be physically protected (again by code) and its well worth just using a 6 even if you could get by with smaller, saves having to put it in conduit or hide it to be proper.

To clarify, some of what I have does not meet code and I cannot change it at this point. So my question is really how do I make it safe with what I have to work with.

 

[mrb]

it just had to meet code when it was installed. You can replace your service and refeed existing wiring as long as you dont change anything that would require existing wiring be brought up to code (or something like that)

that said, if you are just now installing the feeder to the shop it should be 4 wire.

 

[ToolLover]

I think the NEC (National Electric Code) has changed.
The neutral and the ground are no longer bonded together.
The ground is attached to the grounding bus with bonding screw to the box, also to the water pipe, grounded bushings and the ground rod only.
The neutral is attached to the isolated neutral bus.
Only three ground wires can be placed under each lug on the grounding bus.
Note there are two buses in the new boxes.
One comes with a ground bonding screw. That is the grounding bus
One comes isolated and that is for all neutrals.
Any garage has to have a GFI main breaker today.
Bonding the neutral and ground together will not work with a GFI.
(It will trip every time the breaker is turned on.)
Anyway, thats the way it is!

 

[mrb]

I think the NEC (National Electric Code) has changed.
The neutral and the ground are no longer bonded together.
The ground is attached to the grounding bus with bonding screw to the box, also to the water pipe, grounded bushings and the ground rod only.
The neutral is attached to the isolated neutral bus.
Only three ground wires can be placed under each lug on the grounding bus.
Note there are two buses in the new boxes.
One comes with a ground bonding screw. That is the grounding bus
One comes isolated and that is for all neutrals.
Any garage has to have a GFI main breaker today.
Bonding the neutral and ground together will not work with a GFI.
(It will trip every time the breaker is turned on.)
Anyway, thats the way it is!

neutral and ground are not bonded at the subpanel where there is a 4 wire feeder. If there is an existing 3 wire feeder you HAVE to bond the neutral and ground. 4 wire feeder is required for new installs.

you do not use a GFCI main breaker. Receptacles are required to have GFCI protection which can be accomplished with gfci receptacles or a gfci breaker supplying the branch circuit.