adding a GFCI to an ancient, ungrounded outlet

Reply

  #1  
Old 11-28-07, 07:28 AM
Member
Thread Starter
Join Date: Nov 2007
Posts: 9
Received 0 Votes on 0 Posts
adding a GFCI to an ancient, ungrounded outlet

I was sent here by a member at The Planted Tank Forum, a forum for aquatic gardening and told that this place had a good signal-to-noise ratio. I have a fish tank that I want on a GFCI outlet.

I'm a tenant in a house that's on the market. I live here for free in exchange for maintenance and stuff; it's a 25 acre property and a 100 year old house, so the labor adds up, but I'm definitely getting a great deal.

I decided to add a GFCI to the circuit my fish tank is attached to, and there begins my odyssey. Half the house is modern wiring and half is ancient. I have a proper circuit breaker and modern wiring in the kitchen, but the fish tank circuit is (*gasp*) ungrounded. The wiring is so old that it's not color coded so far as I can tell, and it's insulated with this black stuff that must be natural rubber or tar or something and wrapped in fabric.

I don't know anything about the electrical code, though I try to be safe and I know a bit about physics. What are my options here? I guess I ought to get a new junction box and run a new line from the circuit breaker? Formally speaking, I don't know how to do that safely, but I guess I should start reading up. I think I know enough to not kill myself or start fires, but I also know enough to know my limitations.

I have permission from the homeowner to run a separate grounding wire to the outlet, replicating the ghetto-rigged job he did to ground an outlet for his computer. I think this would be sufficient, but I doubt it would be to code.

Any ideas? Thanks.
 
Sponsored Links
  #2  
Old 11-28-07, 07:42 AM
Member
Join Date: Sep 2003
Location: Central New York State
Posts: 13,973
Received 0 Votes on 0 Posts
First, and most important, you probably can do nothing yourself. In a property that is rented and/or that you do not own, doing electrical work is generally illegal. Even if legal, it certainly carries with it extreme liability that you probably do not want to assume.

That being said, let's talk about the issue. What is your goal? Do you want a ground at this receptacle? Do you want GFCI protection at this receptacle? Do you want a new circuit?

If you want a ground, there are several options. It is perfectly legal and within code to run a single insulated wire of the same size (or larger) from the junction box back to the main electrical panel as a ground wire. This sounds like what was done for the computer.

The other option for a ground is to replace the two-wire cable feeding the receptacle with a new three wire cable that includes the ground wire.

If you want GFCI protection, all that has to be done is to install a GFCI receptacle or a GFCI circuit breaker. GFCI circuits work just fine and are code legal with no ground. They do not, however, supply a ground and must be labeled with the labels supplied with the GFCI that indicate "No Equipment Ground."

Installing a GFCI breaker or GFCI receptacle allows you to install three prong receptacles anywhere on the circuit , as long as they are downstream of the GFCI and protected by it. But again, they must be labeled "No Equipment Ground" and "also "GFCI Protected."

The above solutions do not increase the available power but they do enable you to use devices that require a ground for safety with at least some protection.

The solution that provides additional power is to run a new circuit from the main panel. Often in an older home this is the best solution when more power is needed. It does not require attempting to split up existing circuits or feed existing boxes, and it allows you to get power right where you need it.

It is also usually not that difficult a project if you have an unfinished basement below or an unfinished attic or crawl space above the room in question.
 
  #3  
Old 11-28-07, 08:06 AM
Member
Thread Starter
Join Date: Nov 2007
Posts: 9
Received 0 Votes on 0 Posts
I have an unfinished basement fortunately, and this outlet is a straight shot, so physical access should be easy peasy.

I guess I'm not positive what I want at this outlet, though. It's a 15A circuit, and that's way more than sufficient for my current draw. I think I want GFCI, but none of my current fish tank hardware requires a ground. It's news to me that GFCI outlets can be ungrounded, although I did know that the mechanism didn't use the ground. I'd feel somehow better though if the outlet didn't need that "no equipment ground" sticker. GFCI is what I want, right? Adding a ground won't make me any safer?

I have permission from the homeowner to do a certain amount of work, but I don't have permission to add a new circuit to the breaker box. I can tap the ground there if I want to, and I might be able to convince him about adding another circuit or another run if it turns out that doing so would be the most proper, most safe way to get the job done. My roommate is the owner's daughter though, so the landlord/tenant relationship is a bit different than usual; he's more parent than landlord. The owner lives in Hawaii, so if there's repair to be done it's either me (free) or a professional ($$).

However, it seems as if the easiest solution would be to go buy a spool of green wire and install a parallel run. I'm glad to hear that it's legal to do so. Let me know what you think.

Tremendous thanks for the advice.
 
  #4  
Old 11-28-07, 08:26 AM
Member
Join Date: Sep 2003
Location: Central New York State
Posts: 13,973
Received 0 Votes on 0 Posts
If none of your equipment requires a ground (ie has a three prong plug) then grounding the receptacle will do nothing except make the electrical box grounded.

If you are concerned because of the water in a fish tank, then a GFCI will provide some degree of protection.

Do you need a new circuit? It's a 15 amp circuit, which is adequate for your needs. Or is it? What else is on this circuit? Are most or all of the receptacles in the same room on the circuit? Are some of the bedrooms on the circuit?

Installing a GFCI receptacle is relatively easy. You may have trouble determining which is the neutral and which is the hot wire, but this can be done with a plug in type receptacle tester, and examining the existing receptacle is always the place to start.

The hardest part of adding a ground wire will be feeding the ground wire into the box. Obviously this is done with the power off and some trial and error.

As your roommate is family and you are not renting (and I assume have no lease), your roommate can probably do the work, with you assisting.

I do not recommend that you attempt a new circuit in any residence (owned or not) until you have more knowledge. Start with the book "Wiring Simplified" available at the big box stores and on-line before doing anything. The book will tell you how to install a GFCI receptacle and will provide tips on snaking wires.

Good luck, and let us know how things turn out.
 
  #5  
Old 11-28-07, 09:21 PM
Member
Thread Starter
Join Date: Nov 2007
Posts: 9
Received 0 Votes on 0 Posts
Well, I ran a separate ground from the breaker box. The job wouldn't have felt complete without it, even though I intellectually know that it isn't adding any safety. That was by far the easiest run I've ever pulled/fished. It's still going to take me three trips to the hardware store to complete though, 'cause my new outlet didn't fit in the old box, and when I'd solved that problem I'd discovered that I'd gotten the wrong faceplate.

Oh yeah, one more thing. I'm not proud to say how long it took me to figure out that neutral and ground were the same thing in the breaker box.

Nonetheless, thanks for the advice.
 
Reply

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Thread Tools
Search this Thread
 
Ask a Question
Question Title:
Description:
Your question will be posted in: