power outlet

[blackcat]

I have two-prong outlet(old outlet) and like to change to grounding three-prong outlet. Since I have a lot of appliance that require three-prong outlet. I know I can use connector to covert to three-prong. I would rather change the power outlet. I got a three-prong grounding outlet from Home Depot. Some people say that I can just wire the third wire to the metal box and the grounding outlet, but some people consider I should not do that it is not safe.

Should I just wire the third wire, connect between metal box and the three-prong grounding outlet?

Thanks

[buffalobill]

any 3 prong 110v outlet should be physically grounded to a grounded box. chances are there is no ground available at the metal box. there are testers for this if you have no meter. if you have a meter measure 110v hot prong is smaller to the metal box. larger prong is common terminal.

see:

blackcat wrote:

[blackcat]

Thanks. I use 120V power, at the outlet prong is a metal box. Is the metal box called grounded box? I have never done this kind of work. Please help me. I just bought the three-prong outlet it comes with a grounded screw, but I am not very sure where should I connect with the grounded screw. I have power voltage meter, just bought one. I just wanted to be cautious.

Thanks

buffalobill wrote:

[Don Phillipson]

It is unsafe to do this work yourself unless you genuinely know which metal parts are live and which are grounded and why.

[trader4]

Simple solution is to replace the outlet with a GFCI which will provide protection with or without a ground.

[hallerb]

older boxes are often too physically small to have a GFCI fit:(

what you do is buy a book wiring simplified and do some reading.

to check box to see if its grounded try powering a 100 watt lamp between the metal box and hot side of receptable.

if it powers a lamp it should be a decent ground. generally BX that spiral would metal cover cable is a good but not perfect ground

[Al Bundy]

"blackcat" wrote in news: [e-mail]:

Bases on your couple of posts, you should not be messing with home electricity. I don't mean that as a slam. You could hurt yourself, hurt someone else, or create an unsafe condition unknowingly. Also, assuming this is your house, you could set something up wrong, by that I mean functional but a code violation, and when you go to sell it a home inspection will catch it and hold up the sale.

And with a handle of "blackcat", your luck sounds doomed :-)

[Tom The Great]

Questions like this imply to me that you aren't up to speed with the code. Have a qualified electrician check for proper grounding in the box, or upgrade your outlets via GFCI protection.

Just curious, do you have Armored Cable [AC] also called BX wiring?

later,

tom @

[<aemeijers]

I&#39;ll second this one- OP is clearly in over their head, which is not a slam, everyone has to start somewhere. Either hire somebody, or put off doing any rewiring till they take a &#39;basic home wiring&#39; course at the vo-ed center or something. Is possible to kill oneself or burn the house down, now or

20 years later, by doing this stuff wrong. I&#39;ve found a few things here that the previous homeowner did that made me shudder - the only reason they didn&#39;t burn the place down is because they were on low-draw circuits. I can do basic stuff, but for complicated stuff, I pull out the dummies guide with diagrams, or consult the actual experts I happen to be related to.

aem sends...

[Tom Horne, Electrician]

Modern Armored cable has a bonding strip inside the armor that assures a low impedance path through the cable&#39;s metal jacket for any fault current that is likely to be imposed. BX cable is the original form of that cable that was manufactured at the Bronx plant of the General Electric Company hence the name BX. BX has devolved into a common trade name for armored cable but the early BX does not contain a bonding strip and is not an adequate path for equipment grounding. Testing grounding pathways with actual loads such as light bulbs can cause arcing along the cable jacket. Such test loads should be applied only long enough to get a stable voltage reading with which to calculate the voltage drop in the grounding path. If that voltage reading does not stabilize at once remove the test load and resort to a testing device such as the Ideal Sure Test.

The grounding pathway through unbonded BX cable can change impedance quite rapidly in the presence of water or other corrosive influences.

[Tekkie®]

blackcat posted for all of us...

Did a lot of research didn&#39;t you? NOT Google broken at your house?

[blackcat]

Which kind of GVCI should I have, 15 Amp or 20 Amp? Thanks in advnce.

[e-mail] wrote: