View Full Version : Grounding an Outlet
nubuilder
Jul 24, 2005, 06:45 PM
I am moving into an older house that has only 2-prong outlets. Some are 3-prong, but they are not grounded (I have a power strip that tells you if it is gounded or not).
I found this at Ace Hardware. http://www.acehardware.com/product/index.jsp?productId=1292626&cp=1254879.1254958.1259167&parentPage=family
How do I install it so that the outlet is properly gounded?
labman
Jul 25, 2005, 07:15 AM
The clamp is meant to go on a metal water pipe. You then run a wire from the screw on the clamp to a screw on the frame of the outlet. I can't say if such an arrangement meets code. You may find it helpful to look at this thread, https://www.askmehelpdesk.com/showthread.php?t=11184
nubuilder
Jul 25, 2005, 08:25 PM
That link helped. I'll take off my face plate and see if there is the other green screw on the end. If not, I'll try the 3 prong to 2 prong converter with the screw on the face plate acting as the ground. If this works or doesn't, I'll let you know.
I should let you know that my surge protector has an indicator to which it is grounded.
Here it is if you want to look at it: RCA surge protector (8 outlets, 2100 joules) (http://www.rca.com/product/viewdetail/0,2588,PI700875-CI123,00.html?)
Picture 1 (http://electrogalaxy.dtopinc.com/catalogimages/rcaps83202c2.jpg)
Picture 2 (http://www.ebizenterprise.com/ProductImages/4images/imagesr/rcaps83202c2.jpg)
nubuilder
Jul 26, 2005, 06:26 PM
OK, the 3 prog to 2 prong grounded to the screw didn't work.
There is a 3rd screw for grounding. There is a bare copper wire run to it.
The electricity to the outlets is from a light in the ceiling.
Could I run a wire from the third screw to the piece of wood it is on? (the box the outlet is in is metal, not plastic)?
labman
Jul 26, 2005, 07:11 PM
I don't quite understand. You can't ground a wire by screwing it to a piece of wood. As I explained it that other thread, in some older construction, there are 2 prong outlets installed in grounded metal boxes. You can just unscrew them and replace them with 3 prong ones. A metal box can have a ground wire attached to it, but if that wire is not grounded, the box and outlet will not be. You may be able to open the light fixture and connect existing ground wires. If not, you are back to the clamp on the water pipe. The clamp to the water pipe is one of the most reliable grounds, often added to eliminate interference in electronics.
nubuilder
Jul 26, 2005, 09:06 PM
What could I run the ground wire to (other than a pipe) to ground it?
kp2171
Jul 26, 2005, 09:24 PM
Your choices are to connect it to the box (if the box is grounded), run a ground line to another nearby box that is grounded, or get it to a pipe that eventually runs into earth.
labman
Jul 27, 2005, 06:44 AM
I am sure the breaker box itself is grounded. It should have a buss with extra ground terminals. Once you take the cover off, both the ground and hot wires are exposed, be careful. The alternative is a ground rod driven deep into the ground where is is always damp. Likely there is already one outside where the electrical service entry is. You can also drill a hole in the basement or garage floor. Just be careful where, not over a drain or something.
Press2Esc
Jul 27, 2005, 07:19 AM
Labman,
How do you know the outlet boxes are grounded? Have you measure them with an ohm meter? If it measures a zero ohms (short) - they are grounded. 2-wire or 3-wire plugs, in older homes are not typically grounded. Of course, depending on your access (e.g. crawl space, attic, wall fish, etc), if you or your electrician has enough access an outlet to be able to ground it, doesn't it make sense to run a new 3 conductor wire back to the main breaker box for code and safety reason??
Be forewarned, with the heavy of usage of PVC through the years, grounding of water pipes is no guarantee. If you check your electrical service entry point, you will likely see a nearby ground rod. This is your earth ground for your house & main electrical panel...
P2E
I don't quite understand. You can't ground a wire by screwing it to a piece of wood. As I explained it that other thread, in some older construction, there are 2 prong outlets installed in grounded metal boxes. You can just unscrew them and replace them with 3 prong ones. A metal box can have a ground wire attached to it, but if that wire is not grounded, the box and outlet will not be. You may be able to open the light fixture and connect existing ground wires. If not, you are back to the clamp on the water pipe. The clamp to the water pipe is one of the most reliable grounds, often added to eliminate interference in electronics.
nubuilder
Jul 27, 2005, 03:23 PM
I'll check the fuse box (don't have breakers). I do not have an ohm meter to check the outlet. I do not know if the outlet box is grounded. It is attached to wood.
I won't be posting again until Monday, April 1.
labman
Jul 27, 2005, 04:16 PM
If a metal box is grounded one way or another, an outlet screwed to it is grounded. If the surge protector isn't grounded when plugged in, neither is the box.
You haven't said how old the older house is, or if you are buying or renting. In the other thread, m3rdpower is stuck in a poorly wired rental. My son had that problem too. If you own the house, and it is old enough to have fuses and metal boxes, it may be easier to retro fit proper grounds. A grounded outlet is literally that, having a conductive path from the frame of the outlet to damp ground with unlimited electrons. In modern construction, it is usually actual wires back to the breaker box connected to a rod going deep into the ground. In the past, it was often metal conduit or flex back to the box. Unfortunately for a while houses were wired up with non metallic wire without the third wire for grounding. After enough houses burn down or people are electrocuted, they tighten the code. Where they used plastic boxes and stapled the NM cable inside the wall, updating is a pain.
You need to figure out what you have and how much work you want to do, Could be as simple as connecting wires that are already there. To do it right, you could have to run new cables. As long as the surge protector indicates whether the outlet is properly grounded, you shouldn't need to do other checking. It is easy enough to do with even a $5 multimeter.
nubuilder
Jul 27, 2005, 06:32 PM
The house is 48 years old. I own the house now.
I know what you are talking about with the newer houses and driving a metal stake deep into the ground, I have seen what this looks like.
I'll see if the fuse box is grounded.
I will not be posting again until Monday, April 1.
Press2Esc
Jul 31, 2005, 04:26 AM
The house is 48 years old. I own the house now.
I know what you are talking about with the newer houses and driving a metal stake deep into the ground, I have seen what this looks like.
I'll see if the fuse box is grounded.
I will not be posting again until Monday, April 1.
hmmm, no big hurry nubuilder... get back to it whenever you can & just enjoy your "little" break.. :D
nubuilder
Aug 3, 2005, 05:23 PM
How do I tell if the fuse box is grounded?
labman
Aug 3, 2005, 07:06 PM
If you have a meter or a test light, remove a fuse and see if you have 115 volts between the center contact for the fuse and the metal of the box. I would be very surprised if you don't.
nubuilder
Aug 4, 2005, 04:25 PM
I do not have any testing equipement. All I have is a AA, AAA, C, D, and 9V tester for my batteries and my power strip with the indicator on it (see the 3rd post on P.1).
What could I use as a test light, or what is a test light?
(F.Y.I.-I tried the power strip on a 2 prong outlet in the living room with a 3 prong to 2 prong converter, and it said it was grounded.)
labman
Aug 4, 2005, 04:46 PM
I do not have any testing equipement. All I have is a AA, AAA, C, D, and 9V tester for my batteries and my power strip with the indicator on it (see the 3rd post on P.1).
What could I use as a test light, or what is a test light?
(F.Y.I.-I tried the power strip on a 2 prong outlet in the living room with a 3 prong to 2 prong converter, and it said it was grounded.)
I would trust your power strip and declare the problem solved.
nubuilder
Aug 4, 2005, 06:11 PM
No this is not solved. The outlets in the LIVING ROOM were grounded, but they were put in many years ago.
The wiring in the basement room was done long after the house was done, maybe 20 to 25 years ago. The outlets have the third prong (unlike the original wiring).
I'll try it again in the basement again tomorrow. Let you know tomorrow in the afternoon.
nubuilder
Aug 5, 2005, 12:20 PM
LIVING ROOM
I have a 3 to 2 prong converter on it. When I only had 2 prong things plugged in, it said it wasn't grounded. When I plugged a 3 prong item into it, it instantly said it was grounded.
BASEMENT
The outlets in the basement are 3 prong. I plugged in the power strip (with no adapter) and it said it wasn't grounded, but as soon as I plugged in something with 3 prongs, it said it was grounded.
As soon as I plugged it in at my friends house (which is only 20 years old), it said it was grounded and nothing was plugged into it.
Can anyone explain this to me?
labman
Aug 5, 2005, 01:03 PM
At the moment, it doesn't make any sense to me. It really isn't safe living in a house that doesn't have properly grounded outlets. As I have indicated, it can be fairly easy to retrofit grounds depending on the details of the original wiring. If you are going to try to do the work yourself, you will need to pick a few basic tools, a test meter at least. The voltage probes are faster and safer for many trouble shooting uses. I wouldn't trust that outlet strip.
Your other alternative, perhaps expensive, is to have an electrician do the work.
nubuilder
Aug 5, 2005, 04:02 PM
O.K. I'll figure it out from here.
Thanks for all the help and suggestions! :cool: ;) :D :)
27e86ct
Aug 25, 2009, 09:02 PM
First, an Ohm's meter will only test resistance between the two points that the probes are touching. This is not a way to see if you have ground. If you are in an older home that uses fuses, you most likely have conduit. You can ground the conduit to a water pite with grounding straps and a jumper wire. If you take this rout, make sure there is a jumper wire bridging the gap in pipe between the water meter. If this is not there, install one even if you don't use the water pipes as ground. Once the conduit is grounded, assuming your box is metal, you can simply use a grounding screw and bare copper or green PVC coated wire attached to the box for your ground.
tkrussell
Aug 26, 2009, 10:56 AM
This thread is 4 years old.
Please refrain from answering questions older than a few months.
Thread Closed.