2 prong to 3 prong outlet conversion?

We just bought a new house and want to upgrade the electrical system, some of which was done in the 60's when the house was built. The vast majority of the electrical outlets have only 2 wires, the ground terminal is missing.

Some of the outlets are in the basement, where the wiring is partially accessible however.

Is it legal (according to the electrical code) for me to change the outlet to a more modern 3 prong type and to obtain a ground from a nearby copper pipe or from one of the nearby plugs that already have a

3 prong outlet???? I notice the previous owner did this in several locations, but I need to know if it's legal to obtain a ground in this manner???

We live in Maine, but belive the National Code is the one that has jurisdiction.

Thanks,

A
Reply to
Ari
Loading thread data ...

You should not use the plumbing system as the path-to-ground for your outlets, no. The simple "solution" is to replace the receptacles with GFCI outlets, and mark them "no equipment ground", (which labels ought to come with the recepticles). This will get you within shouting distance of the same level of protection.

The complex solution is to run completely new wire.

An intermediate solution is to pull a separate ground wire, and run it back to your service panel. If you do that, you want to make sure that no ground wire serves the devices on more than on circut, and that each one is big enough to handle the circut it's on.

Reply to
Goedjn

Good idea to GFI protect the basement outlets, except any for a freezer/refrigerator.

Reply to
Jeff

If you are planning to pull a ground wire back to the panel, you might as well just plan on rewiring the outlets properly and legally with new grounded cable. Any separate ground that you run is going to be a kluge install and most likely would not pass code with an honest and knowlegable electrical inspector. Not being code compliant can affect your liability and fire insurance coverage.

As another poster says, if you don't want to go to all that trouble and expense, putting in the GFCI's with the appropriate labels would be the easy (and perfectly legal) way to go.

Beachcomber

Reply to
Beachcomber

I haven't checked the most recent revision of the code to make sure it's still there, but the code specifically allows you to run a separate ground wire when upgrading old work. Think about it; the old ungrounded wiring is code compliant because there was no grounded requirement when it was installed. Adding a supplemental grounding wire can only make it safer (assuming the grounding wire goes back to the panel or grounding electrode system so a fault can't energize another circuit.)

Bob

Reply to
zxcvbob

Anything you touch is going to have to meet current code and the old wiring probably won't if it's sixty years old. If you're going to pull a ground through your walls, pulling new wiring isn't much more trouble.

Reply to
AZ Nomad

So to serve more than one circuit, you need to pull more than one ground wire? Wouldn't it work just as well to pull a thicker ground wire?

Reply to
peter

Probably. Esp. if you use 10 AWG wire. I mean, how likely are you the get three simultaneous high-resistance shorts from the same leg of your panel?

But I know that the the former works, is safe, and is legal, and I don't know any of that for sure about the latter.

Reply to
Goedjn

Equipment Grounding Conductors (EGCs) are sized for the size of the largest Over Current Protective Device supplying the conductors in a given box or other enclosure. As an extreme example lets use a junction box for the kitchen and laundry circuits in an apartment. If the box contains a fifty ampere stove circuit, a thirty ampere dryer circuit, a twenty ampere laundry circuit, a twenty ampere multiwire kitchen counter top circuits, a fifteen ampere multi wire dishwasher and disposal circuit, and a fifteen ampere multiwire refrigerator and microwave oven circuit it still only needs one equipment grounding conductor. That EGC is sized for the fifty ampere breaker for the stove. The only reason that the US NEC would require you to increase the size of the EGC is if you increased the size of the current carrying conductors to compensate for voltage drop. It just is not likely that there will be simultaneous faults on two or more of the circuits that EGC was installed to protect.

Reply to
Thomas D. Horne, FF EMT

Thank you all for commenting, I appreciate all the info!

I went down in the basement and pulled the cover off the entrance panel. The inspection I did was very interesting, especially in light of all the comments I've received to this post.

The large (existing) ground wire that goes to the ground rod near the water main entrance IS the system ground for the electrical panel!!!!! Although the panel is on one end of the house and the water main is on the opposite end, it appears the original installer ran 50 feet of large gauge copper across the middle of the basement in order to ground the electrical service entrance panel.

So, that big ole copper wire that is very accessible should make a fine ground!

Regarding the comments by some that I should just rip out the old 2 conductor wire and install 3 conductor wire in it's place..... do keep in mind that the basement is finished, and gaining access to all the wires that feed the house would require a major demolition and restoration after the new wires were run. Not very practical::>

However, adding a ground wire is much more practical because the added ground wire doesn't have to follow the path of the original 2 conductor wiring.

Again, thanks to all who commented, I'll post an update here later on.

Regards,

A
Reply to
Ari

HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.