[Spitfired]

Ok, so I've got 2 prong outlets in my near 100 year old house. The outlet boxes are metal as well as the conduit.
I'd like to convert them to 3-prong, but I don't have a ground wire to tap. Can I ground to the box simply by screwing the outlet onto it? In research, I read that most older homes have all the boxes/conduit grounded, but I'm not 100% sure.
How can I test to see if my boxes are grounded?

 

[splat]

Maybe.

first check your local electrical codes, 2nd go to home depot and get a curcuit test , the type you plug in and the lights light up to tell you if it is wired correctly or not.

 

[Spitfired]

So basically, wire one of the new outlets in and test it?

 

[N8 v2.0]

Ok, so I've got 2 prong outlets in my near 100 year old house. The outlet boxes are metal as well as the conduit.
I'd like to convert them to 3-prong, but I don't have a ground wire to tap. Can I ground to the box simply by screwing the outlet onto it? In research, I read that most older homes have all the boxes/conduit grounded, but I'm not 100% sure.
How can I test to see if my boxes are grounded?

Chances are you have metal flex conduit to your outlet boxes which is not an approved ground per the NEC. However, if you are lucky you may have rigid steel conduit connecting your system in which case grounding the receptical to the box is approved.

 

[Brian HCM#1]

Chances are you have metal flex conduit to your outlet boxes which is not an approved ground per the NEC. However, if you are lucky you may have rigid steel conduit connecting your system in which case grounding the receptical to the box is approved.

If the house is 100 years old, it's probably knob & tube wiring.

 

[N8 v2.0]

If the house is 100 years old, it's probably knob & tube wiring.

Maybe in the attic... not the walls...??

I've only ever seen it being used in the attic spaces...

 

[Brian HCM#1]

Maybe in the attic... not the walls...??

I've only ever seen it being used in the attic spaces...

It's in the walls too.

 

[splat]

So basically, wire one of the new outlets in and test it?

Bingo!

and test every outlet you wire there after .

 

[psychobiker]

you can put 3 prongs in there but that alone will not make them grounded outlets spend some money and rewire the house... I've seen too many people lose there homes due to this kind of "home improvement" contact a NARI sponsored electrician. its your life

 

[Spitfired]

Ok, so I disected one of the outlets that is already three prong, and they have a ground wire run to them (looks like a fairly new cable).

Knob and Tube is the ceramic stuff, right? Theres a tiny bit in the basement, but as far as I can tell there doesn't really seem to actually be any conduit anywhere... going up the walls
The wiring in the basement is a total cluster****. We had breakers installed recently, but didn't really rewire anything past them. Out of the boxes, the wires go all over the basement ceiling.

 

[psychobiker]

keep messing with it and youll be spitting fire, look at the breakers. white is neutral black is hot bare copper is ground. remember there is over 300 volts coming into a breaker box

 

[splat]

: remember there is over 300 volts coming into a breaker box

there is ? not last time I checked !

 

[johnbryanpeters]

there is ? not last time I checked !

Peak. sqrt(2) * 220

 

[N8 v2.0]

Peak. sqrt(2) * 220

LOL!

 

[splat]

Peak. sqrt(2) * 220

that is in a 3 phase Delta Config .
Most Hoshold supply is 3 phase Y
and in a Standard Y configuration it is sqrt(2) * Cos(120) * 220

 

[Ian F]

Guys... please... if you know not of what you speak, don't say anything... a lot of WRONG info here. It's one thing to spew crap when it's about bikes and it really doesn't matter (hell knows I do it enough...), but quite another when someone's life depends on it.

I design this crap for a living. I NEVER give out design advice online.

Please... Hire an electrician.

 

[jonKranked]

greg, get in touch w/ stuntmatty. he's local, and he renovates houses. i'm sure he'd be glad to lend you a hand, or at least point you in the right direction.

also be sure to add a flux capacitor to your house.

 

[N8 v2.0]

Guys... please... if you know not of what you speak, don't say anything... a lot of WRONG info here. It's one thing to spew crap when it's about bikes and it really doesn't matter (hell knows I do it enough...), but quite another when someone's life depends on it.

I design this crap for a living. I NEVER give out design advice online.

Please... Hire an electrician.

LOL!

We are only a bunch of electrical engineers in here....

Here's my 2005 NEC right here.

:eviltongu

 

[DirtyMike]

Guys... please... if you know not of what you speak, don't say anything... a lot of WRONG info here. It's one thing to spew crap when it's about bikes and it really doesn't matter (hell knows I do it enough...), but quite another when someone's life depends on it.

I design this crap for a living. I NEVER give out design advice online.

Please... Hire an electrician.

I have to agree with this statement, its too hard to describe exactly what needs to be said and SEEN, there IS enough voltage coming into your house to KILL you. As in there is enough [power that you can get enough amperage across your heart to .... for lack of a better word.... Make it explode. Call a professional, very worth it

 

[splat]

I have to agree with this statement, its too hard to describe exactly what needs to be said and SEEN, there IS enough voltage coming into your house to KILL you. As in there is enough [power that you can get enough amperage across your heart to .... for lack of a better word.... Make it explode. Call a professional, very worth it

Yeah and the same can be said of your car battery too!

and the voltage across your heart WILL NOT make it explode , it will just Screw up the Beating pattern ( if not stop it )

 

[N8 v2.0]

Ok, so I've got 2 prong outlets in my near 100 year old house. The outlet boxes are metal as well as the conduit.
I'd like to convert them to 3-prong, but I don't have a ground wire to tap. Can I ground to the box simply by screwing the outlet onto it? In research, I read that most older homes have all the boxes/conduit grounded, but I'm not 100% sure.
How can I test to see if my boxes are grounded?

Look, it's all clearly explained here:
http://tinyurl.com/dk4ug