I’m moving in about a week, and the new place isn’t very new at all. Most of the electrical outlets throughout the place are ungrounded. With all of the computer equipment and other assorted electronic gizmos I have, this presents a problem.
Aside from tearing up walls and running the proper 3-conductor conduit from each outlet back to the main panel, is there any way to sufficiently ground at least a few outlets? This place has no attic and no under-floor access (oh, how I hate Eichler’s)
I’m renting the place, but can make some changes to the place (e.g. I’m running ethernet to each room).
Any books, websites, etc. with info are most appreciated.
Older homes frequently have two-prong receptacles instead of the more modern three. These receptacles have no safety ground, and the cabling usually has no ground wire. Neither the NEC or CEC permits installing new 2 prong receptacles anymore. :mad:
There are several different approaches to solving this:
1) If the wiring is done through conduit or BX, and the
conduit is continuous back to the panel, you can connect
the third prong of a new receptacle to the receptacle
box. NEC mainly - CEC frowns on this practice.
2) If there is a metallic cold water pipe going nearby, and
it's electrically continuous to the main house ground
point, you can run a conductor to it from the third
prong. You MUST NOT assume that the pipe is continuous,
unless you can visually check the entire length and/or
test it. Testing grounds is tricky - see "Testing
Grounds" section.
3) Run a ground conductor back to the main panel.
4) :) Easiest: install a GFCI receptacle. The ground lug
should not be connected to anything, but the GFCI
protection itself will serve instead. The GFCI
will also protect downstream (possibly also two prong
outlets). If you do this to protect downstream outlets,
the grounds must not be connected together. Since it
wouldn't be connected to a real ground, a wiring fault
could energize the cases of 3 prong devices connected
to other outlets. Be sure, though, that there aren't
indirect ground plug connections, such as via the sheath
on BX cable.
The CEC permits you to replace a two prong receptacle with a three
prong if you fill the U ground with a non-conducting goop.
Like caulking compound. This is not permitted in the NEC.
The NEC requires that three prong receptacles without ground
that are protected by GFCI must be labelled as such.
I did this to an entire house once. And it passed inspection (well, the home inspector hired by the buyer didn’t detect any problems)
I bought a spool of 12-gauge green insulated electrical wire from my local “If it ain’t here it don’t exist” hardware store and then removed all the baseboards. I know the circuits were not this simple, but for each room in the house I ran a ground circuit connecting each outlet to a common ground wire that ran along the baseboard (I then reinstalled the baseboards over the wire). Specifically, I ran a short wire from the ground lug on the (new) outlet down behind the wall to the floor. I had to poke a hole in the wall just above the framing 2x4 for the wire to exit into the room, but the baseboards covered the holes. This wire was then spliced into the main grounding wire for that room which in turn ran all the way to the neutral bus in the main breaker panel.
Don’t link all the outlets in the house to the same ground wire because that turns your house into a huge Farakahn cage…or something.
I shied away from the cold water pipe trick just in case a) that connection came loose for some reason and b) in the unlikely event that pipe fell into disuse and became detached from the rest of the water system.
GFCI breakers are a $10 good idea but can be a tight fit sometimes. Make sure you put the "live"wire and the “downstream” wire in their correct respective places on the breaker. Otherwise it won’t have the desired effect. Oh yeah, and beware of brittle wires. They can break easily if kinked and muscled (like you’ll most likely have to do if you go the breaker way.
ANOTHER QUESTION, though. If an appliance suffers a ground fault and the juice is then diverted to the ground wire (rather than the body of the appliance). Why doesn’t the neutral bus become energized as a result?
You cannot connect a ground to a cold water pipe further than 5 feet from where the pipe enters the building. If you connect to the pipe at other locations you risk electrocuting somebody in the shower.
An ungrounded GFCI receptacle doesn’t provide a ground (sounds obvious enough). A GFCI protects people from electrocution. It doesn’t protect equipment. In fact, if you install a GFCI receptacle without ground, you must label it “No equipment ground”.
If by this you mean that you hid splices under the baseboard, then this is wrong. You aren’t supposed to hide splices. It would have been much better (and legal) to string wire from outlet to outlet, splicing them inside the outlet box. Probably less work, too.
If possible, run a distinct ground for each circuit.
It’s usually simple to cut out old boxes and replace them with deep “old work” boxes. Makes fishing wire around much easier, too, since you’ll have a 2x3 hole in the wall.
Typically you find the stud (to one side or the other of the box), pry the box away from the stud with a big screwdriver, and cut the nails and/or clamp with either a mini-hack (hacksaw where the blade sticks out), a recip blade handle (handle that holds a reciprocating saw blade) with a metal cutting blade, or a reciprocating saw with a metal cutting blade. A recip saw works well, but you have to be really careful.
If you screw up, you’ve got to do a drywall repair. The repair itself is pretty trivial, but the finish might not be (things like wallpaper, faux paint and textured paint are tricky).
It does for a moment… and then the breaker trips. Think about it, you’ve just completed a short circuit to ground.
What the others said, plus check out Home Depots Home Improvement book. Very well laid out and easy to follow. I ended up running new 3 wire lines, but I had pretty easy access to fish lines via the basement and attics. Most household stuff doesn’t use a ground, so you really only need to do some outlets for the computer and for the home entertainment system (assuming you are using a surge protecter/power strip).
Another (not insignificant) consideration is that a lot of the old two-wire lines are paper insulated, and are wonderful at allowing smoldering fires to spread quickly throughout the house. That was my prime motivation in changing out all of my wiring. (And I am no Bob Villa, but the work is pretty straight forward, if incredibly tedious)
It goes without saying that you should become initimate with your fuse box/breaker box before you start tearing in, as well as buying a basic circuit tester and multimeter. The pisser about 'lectricity is that you can’t see the damned stuff, and boy oh boy, it loves to suprise ya… Of course, it is hard to kill yourself with 120V AC, but if you took a hit, and fell off a ladder, and smashed a coffee table, in front of your so-called friends, they will laugh themselves to tears for years to come. Or so I am told.
Well, not really. Don’t mess with house wiring without the breaker OFF and a tag affixed it that says someone is working on the circuit so LEAVE IT OFF YOU DIPSHIT.
And after you throw the breaker OFF, check to make sure that the circuit is, in fact, OFF.
Based on my experience, I’d say forget about converting.
Instead, install entirely new grounded outlets in the rooms where you need them. You probably only need them in a couple of places – for your computer equipment and your audio/video equipment. Most other appliances will work fine from non-grounded outlets.
It’s usually easier to do an entirely new installation, putting a new box in the wall and running cable back to the breaker box, than to try messing around attempting to work with the old wiring that is there.
Philster what is the “CEC”? If it is the California Electrical Code, there are major flaws in your first reply.
The California Electrical Code doesn’t “frown” on anything. The CEC states what’s acceptable and what’s not acceptable. Metallic conduit and BX with the bond strip are acceptable methods for providing an equipment ground.
The connection of an equipment grounding conductor, to a metallic water pipe(that’s being used as a part of the grounding electrode system) must be made to the water pipe within 5’ of the pipe entering the structure.
I’m not Philster, but it’s the Canadian Electrical Code. The answer Philster posted is taken from the Electrical Wiring FAQ, which is posted to the usenet group misc.consumers.house.
Last I checked (which was a while ago), your points #1 and #4 are incorrect with respect to the Canadian Electrical Code. You can’t use conduit or BX shield (aka “in-wall toaster”) as ground, and you can fill in a ground hole with caulk. Point #2 is correct, and point #3 (the mystery point) is impossible for me to verify .
The FAQ deals with both the NEC and CEC because it is written by an American and a Canadian, and is aimed at homeowners from both sides of the border. To me, it provides a reasonably clear laymans description of the codes.
What may or may not be legal in your area may vary, but it’s never a good idea to ground to a water pipe. You want your water pipes to all be grounded for safety reasons, but you don’t want anything else to use them as a ground.
It used to be that you were required to ground your electrical system through the water pipe, but that changed quite a ways back.
Of course, it is hard to kill yourself with 120V AC, but if you took a hit, and fell off a ladder, and smashed a coffee table, in front of your so-called friends, they will laugh themselves to tears for years to come. Or so I am told.