advertisement
Forums

The Forum is sponsored by 
 

AAPL stock: Click Here

You are currently viewing the Tips and Deals forum
How important are grounded 3-prong outlets?
Posted by: steve...
Date: June 23, 2006 12:03PM
My new work place only has the regular two-prong outlets. I'm using those gray, three-prong adapters but I know that they aren't really providing a grounded connection. Should I be thinking about getting real three-prong outlets installed?


Options:  Reply • Quote
Re: How important are grounded 3-prong outlets?
Posted by: Ted King
Date: June 23, 2006 12:12PM
I believe that for three prong outlets to actually work correctly there needs to be appropriate wiring - a third wire running to the outlet to actually safety ground the outlet. You can install a three prong outlet, but it won't be any better than the ones there now - in fact, they may be less safe because someone using them may assume they actually do have a saftey ground when they don't. It would be very expensive to redo the wiring, so I suspect your best bet is to use the adapters but be extra careful about using electric devices, especially those with a metal casing or other metal parts that you might touch when plugged in.



Edited 1 time(s). Last edit at 06/23/2006 12:13PM by Ted King.
Options:  Reply • Quote
Re: How important are grounded 3-prong outlets?
Posted by: BigGuynRusty
Date: June 23, 2006 12:13PM
Most boxes are grounded, the adapters will work if the box is grounded, and the adapter is used correctly.

Grounds are very important.

BGnR
Options:  Reply • Quote
Re: How important are grounded 3-prong outlets?
Posted by: davester
Date: June 23, 2006 12:17PM
The 3-prong adapters should only be used if the outlet box is grounded via conduit or armored cable (that's what the little pigtail that attaches to the center screw is for). This is easy to test, but if you don't know how then an electrician should do it. If the boxes are already grounded via a ground wire or armored cable running to the current outlet boxes (though this is unlikely) it is fairly straightforward to put in a 3 prong grounded outlet.

If they are not grounded, then an inexpensive and safe solution is to install GFCIs in those two prong outlets. They won't give you a proper ground so some equipment may not work, but they will shut off in the event of a ground fault, and most jurisdictions approve this type of retrofit setup as code. Be sure to follow the GFCI instructions explicitly to make sure you do it right.



"In science it often happens that scientists say, 'You know that's a really good argument; my position is mistaken,' and then they would actually change their minds and you never hear that old view from them again. They really do it. It doesn't happen as often as it should, because scientists are human and change is sometimes painful. But it happens every day. I cannot recall the last time something like that happened in politics or religion." (1987) -- Carl Sagan



Edited 1 time(s). Last edit at 06/23/2006 12:18PM by davester.
Options:  Reply • Quote
Re: How important are grounded 3-prong outlets?
Posted by: Greg the dogsitter
Date: June 23, 2006 12:19PM
I thought those adapters have a little metal ring, so they can be attached to the wall plate with a screw - this is supposed to provide grounding. Did I just make that up?

GtDS
Options:  Reply • Quote
Re: How important are grounded 3-prong outlets?
Posted by: Ted King
Date: June 23, 2006 12:19PM
BGnR is right, if the the wiring isn't too old there is a good chance the box is grounded. If it is, you need to make sure that the little metal piece that sticks out on the adapter is attached by the metal screw that holds on the plastic face plate (the metal screw will carry the current to the box and then the box ground wire will "take" the current away). But unless you are 100% sure that the box is grounded, it would be best not to assume it is.
Options:  Reply • Quote
Re: How important are grounded 3-prong outlets?
Posted by: BigGuynRusty
Date: June 23, 2006 12:27PM
Quote
Greg the dogsitter
I thought those adapters have a little metal ring, so they can be attached to the wall plate with a screw - this is supposed to provide grounding. Did I just make that up?

GtDS

The box needs to be grounded for that little metal ring to do its magic, GtDS.

BGnR
Options:  Reply • Quote
Re: How important are grounded 3-prong outlets?
Posted by: Ted King
Date: June 23, 2006 12:31PM
davester's advice is probably best - even if you know there is amored cable wiring, it is best not to assume that it is properly grounded. You should test it to make sure. And his advice about intalling GFCI outlets is a good one.
Options:  Reply • Quote
Re: How important are grounded 3-prong outlets?
Posted by: BigGuynRusty
Date: June 23, 2006 12:33PM
Quote
steve...
My new work place only has the regular two-prong outlets. I'm using those gray, three-prong adapters but I know that they aren't really providing a grounded connection. Should I be thinking about getting real three-prong outlets installed?



Steve..., are you or someone renting/leasing this as a business space?
Or, are you just using the space as a place of business, and it is just an apartment (non-business) space?
If it is rented/leased as a business space, and stated on the lease, call your local Fire Department and ask the about the electrical codes for that building.
The landlord might have to replace all the outlets.

BGnR
Options:  Reply • Quote
Re: How important are grounded 3-prong outlets?
Posted by: The Grim Ninja
Date: June 23, 2006 12:42PM
You can also replace the outlets with GFCI outlets.

They perform magic so that you can have a grounded receptacle hooked to a 2-wire system.

(I'm still not absolutely sure what the big deal is with the ground prong. It's just a second neutral).
Options:  Reply • Quote
Re: How important are grounded 3-prong outlets?
Posted by: Tofer
Date: June 23, 2006 12:47PM
Incidentally, here's how the ground wire works:

The metal casing on your piece of equipment is connected to this ground wire, and if there is a short somewhere inside the equipment, the current will travel through the ground wire instead of through you. If the piece of equipment has a plastic case (as most now do), the ground wire is more or less eye candy and doesn't do much.

So, if the thing you are connecting is made of metal, you might want to determine another way to ground the third wire (as noted above). If it is plastic, don't stress so much about it.

-Tofer
Options:  Reply • Quote
Re: How important are grounded 3-prong outlets?
Posted by: Mike Johnson
Date: June 23, 2006 12:58PM
When I had an electrician come out and upgrade my house, he replaced the two prong outlets with three prongs, and instead of running new cable, he installed a GFCI in the first outlet on each circuit. A grounding problem anywhere on the circuit will pop the GFCI -- there's a couple milliseconds of lagtime, but not enough to pose a threat.
Options:  Reply • Quote
Re: How important are grounded 3-prong outlets?
Posted by: steve...
Date: June 23, 2006 01:09PM
Everything I have connected to the adapters is plastic so it looks like I'm OK there. It is my residence where I have a home office. The house is about 50 years old and from what I understand, the outlets are not grounded with conduit or armored cable. I wondered if my Mac stuff was more susceptible to damage, but it sounds like it is a safety issue with people, not Macintoshes. It seems like the best solution is with the GFCI outlets.


Thanks everyone for all the information.


Options:  Reply • Quote
Re: How important are grounded 3-prong outlets?
Posted by: AlphaDog
Date: June 23, 2006 01:14PM
"If it is rented/leased as a business space, and stated on the lease, call your local Fire Department and ask the about the electrical codes for that building.
The landlord might have to replace all the outlets."

Before you have the bright idea that the electrical system might need updating, check your lease very carefully before contacting any public agency. The wily jerk we rented space from in downtown Tacoma had it clearly stated that any upgrades would be done at the expense of the tenant and become the property of the owner of the building, without reimbursement for cost. If you have a lease that contains something similar, don't rattle any cages until you know what might be involved. If the electrical is outdated and the fire department finds out, you might not like the outcome. sad smiley
Options:  Reply • Quote
Re: How important are grounded 3-prong outlets?
Posted by: cbelt3
Date: June 23, 2006 01:19PM
It all has to do with the differece betwen "Ground" and "Return" lines.
[en.wikipedia.org])
The issue is that the "Return" ground may not be at the same potential (Voltage) level as your actual "Earth Ground". You experience this when you get a static electricity shock when you touch a faucet in your house after shuffling your sock-covered feet across dry carpeting (or pet your cat, or etc..)

The GFI solution is NOT allowed in all locations, so be cautious when it comes to codes.

The GFI solution will also not help your surge supressor work properly, as I understand it, not allow your lightning protection plug strip to work. Both of them require a true separate earth ground. The GFI solution will also not help if you work with detecting signals (like Ham radio, AM radio, etc.). The voltage potential of the return line vs. true ground may mess you up.

Your surest solution is to find a way to actually run a ground line into the outlet chain. Metal cold water pipes (IF you've got a ground passthrough on the dielectric barrier that is usually in the water shutoff valve area) are good sources of ground. When I was growing up, we had a late 40's house with two wire plugs. My Dad liked to listen to short wave, so he just bought a copper ground rod, bashed it all the way into the earth next to his bedroom, and ran a true ground line from it to the outlets he hooked his stuff up to.
Options:  Reply • Quote
Re: How important are grounded 3-prong outlets?
Posted by: threeprong
Date: June 23, 2006 02:00PM
Just so you know, three prongs are EXTREMELY, EXTREMELY, EXTREMELY, EXTREMELY, EXTREMELY, EXTREMELY, EXTREMELY, EXTREMELY, EXTREMELY, EXTREMELY, EXTREMELY, EXTREMELY, EXTREMELY, EXTREMELY, EXTREMELY, EXTREMELY, EXTREMELY, EXTREMELY, EXTREMELY, EXTREMELY, EXTREMELY, EXTREMELY, EXTREMELY, EXTREMELY, EXTREMELY, EXTREMELY, EXTREMELY, EXTREMELY, EXTREMELY, EXTREMELY, EXTREMELY, EXTREMELY, EXTREMELY, EXTREMELY, EXTREMELY, EXTREMELY, EXTREMELY, EXTREMELY, EXTREMELY, EXTREMELY, EXTREMELY, EXTREMELY, EXTREMELY, EXTREMELY, EXTREMELY, EXTREMELY, EXTREMELY, EXTREMELY, EXTREMELY, EXTREMELY, EXTREMELY, EXTREMELY, EXTREMELY, EXTREMELY, EXTREMELY, EXTREMELY, EXTREMELY, EXTREMELY, EXTREMELY, EXTREMELY, EXTREMELY, EXTREMELY, EXTREMELY, EXTREMELY, EXTREMELY, EXTREMELY, EXTREMELY, EXTREMELY, EXTREMELY, EXTREMELY, EXTREMELY, EXTREMELY, EXTREMELY, important.




ThreeProng
Options:  Reply • Quote
Re: How important are grounded 3-prong outlets?
Posted by: billb
Date: June 23, 2006 02:31PM
Just the THIRD prong is THAT important ...
Options:  Reply • Quote
Re: How important are grounded 3-prong outlets?
Posted by: RgrF
Date: June 23, 2006 03:27PM
Quote
billb
Just the THIRD prong is THAT important ...

He thinking about a different kind of middle prong.
Options:  Reply • Quote
Re: How important are grounded 3-prong outlets?
Posted by: wowzer
Date: June 24, 2006 02:09AM
Quote
AlphaDog
"Before you have the bright idea that the electrical system might need updating, check your lease very carefully before contacting any public agency. The wily jerk we rented space from in downtown Tacoma had it clearly stated that any upgrades would be done at the expense of the tenant and become the property of the owner of the building, without reimbursement for cost. If you have a lease that contains something similar, don't rattle any cages until you know what might be involved. If the electrical is outdated and the fire department finds out, you might not like the outcome. sad smiley


AlphaDog,

Did you try to call the public agency on the owner, and then had to foot the bill? If so, then I'd say that you were trying to be wily, but the wily landlord had already thought of your wily move ahead of time. winking smiley



All I ever really needed to know, I learned from watching Star Trek.
Options:  Reply • Quote
Sorry, only registered users may post in this forum.

Click here to login

Online Users

Guests: 88
Record Number of Users: 186 on February 20, 2020
Record Number of Guests: 5122 on October 03, 2020