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wis_remod 02-23-2009 02:07 PM

ground ? in old two wire elect system
 
I am installing new lighting & some outlets in a 60 year old house. It only has 2 wire electric system - hot & neutral only, no ground wire. What do you do with the ground wire that is on all the lights purchased? For the outlets can replace with polarized 2 prong outlets, but was told this not acceptable by city electrical inspector. He said if replacing must used grounded 3 prong outlet. So how does this get resolved? Can ground and neutral be joined since they both connect to neutral bus bar in panel? I did not think that was allowed.
Thanks,
Matt M

RippySkippy 02-23-2009 02:14 PM

Quote:

What do you do with the ground wire that is on all the lights purchased?
I generally twist it up and leave it in the box. If you wanted to you can put electrical tape around it as well.

Quote:

For the outlets can replace with polarized 2 prong outlets, but was told this not acceptable by city electrical inspector. He said if replacing must used grounded 3 prong outlet. So how does this get resolved?
In this situation, the only 3 prong outlets you can install are GFCI...and you would need to install one for each duplex you wanted to replace....no down stream protection...

Quote:

Can ground and neutral be joined since they both connect to neutral bus bar in panel? I did not think that was allowed.
NO! if you do and there's a short that does not trip the breaker, external surfaces will become energized...not a biggie for lights...but think about appliances....lots of opportunity for disastrous results...

wis_remod 02-23-2009 02:37 PM

OK, so a GFCI can be used as a replacement in a two wire system?

Also, on the new lights I hooked up the white to white & black to black, left ground unattached. However, at the other end of the wire had both ends of wire attached together to metal frame of light. Does not seem right to me.

Thanks again,
Matt M

RippySkippy 02-23-2009 03:42 PM

yes they can.

Not sure I understand "the other end" ....are you describing the ceiling box wiring or the switch box...

220/221 02-23-2009 04:16 PM

Quote:

In this situation, the only 3 prong outlets you can install are GFCI...and you would need to install one for each duplex you wanted to replace....no down stream protection...


That's not correct. As long as the circuit is GFCI protected, you can install 3 prong receps.

GFCI breakers are often the easiest solution in these cases.

As far as fixture grounds, there's not much you can do with them but cut them off or leave them hanging safely in the jbox.

ACB Electric 02-23-2009 04:43 PM

Quote:

Originally Posted by 220/221 (Post 235474)
That's not correct. As long as the circuit is GFCI protected, you can install 3 prong receps.

GFCI breakers are often the easiest solution in these cases.

As far as fixture grounds, there's not much you can do with them but cut them off or leave them hanging safely in the jbox.


Agree'd, that is actually what is required here for ungrounded plug replacements, either a gfi breaker or install a gfi plug at the panel protecting that circuit, or install a gfi in the first receptical in the circuit putting the rest of the circuit on the load side, I don't like that method as a peice of funature can be placed in front of it then it gets forgotten and when it trips ,,,,, also some of the older boxes don't have suficient space with the existing conductors to properly install a gfi. by gfi'ing all the ungrounded circuits you will also be protecting the lights as well.

the comment about jumping from the neutral to the ground on a receptical,,, definately not, thats an accident waiting to happen

HouseHelper 02-23-2009 04:52 PM

Quote:

Originally Posted by wis_remod (Post 235389)
I am installing new lighting & some outlets in a 60 year old house. It only has 2 wire electric system - hot & neutral only, no ground wire. What do you do with the ground wire that is on all the lights purchased? For the outlets can replace with polarized 2 prong outlets, but was told this not acceptable by city electrical inspector. He said if replacing must used grounded 3 prong outlet. So how does this get resolved? Can ground and neutral be joined since they both connect to neutral bus bar in panel? I did not think that was allowed.
Thanks,
Matt M

The only way you can have a grounded 3 prong outlet is to run a new ground wire back to the panel, or rewire the circuit. A GFCI or a new 2 prong receptacle are both NEC acceptable replacements. Neither has a grounded third "prong".

wis_remod 02-23-2009 05:55 PM

"other end" clarification
 
Hi again,

Thanks for your help on my questions!

The "other end" is the end of the two conductor electric wire after it runs through the three lights.

The light consists of three separate lights mount to a straight bar that is suspended from the ceiling. The wire starts with the ends that are joined with the wires in the ceiling box, then it continues through the light fixture and exits on the other side. It is this end consisting of the two wires that are joined together and fastened to the metal frame that holds the light up
that is attached to the ceiling box. To me it does not seem right - kind of like my previous point of the neutral & ground being combined not being right.

Thanks,
Matt

220/221 02-23-2009 06:02 PM

You need to describe it better.

The conductors should not be tied to the fixture except at the lampholders.

The ground wire, yeah. The black and white, no.

wis_remod 02-23-2009 06:20 PM

I didn't think that was right. Will try to get a picture.

InPhase277 02-23-2009 08:29 PM

Everyone's answered but no one has mentioned the requirement for the supply conductors to be rated at 90 degrees C.

220/221 02-23-2009 11:02 PM

That's because:

1) it's the real world

2) it aint gonna happen

3) it would just confuse him even more.

rgsgww 02-24-2009 08:24 AM

Quote:

Originally Posted by 220/221 (Post 235713)
That's because:

1) it's the real world

2) it aint gonna happen

3) it would just confuse him even more.


Hmm...I don't think I would have torn my walls up, spilled blown in insulation just to pull out that old, groundable bx out because of the darn tw insulation.

windowguy 02-24-2009 08:55 AM

i'm SLOWLY learning electrical guys so take it easy on me here, but i thought you just connect the ground wire from the fixture/outlet to the metal box, don't you?

If its a fixture you take the ground wire from the (light) and fasten it to the metal box, and if you are going from a 2 prong outlet to a 3 prong outlet you buy some green wire and connect the green screw on the outlet to the metal box with green wire.

I thought it was that simple. and i thought that's what his question was but boy i'm seeing all these GFI replies and i'm doubting myself now.

rgsgww 02-24-2009 12:07 PM

Quote:

Originally Posted by windowguy (Post 235851)
i'm SLOWLY learning electrical guys so take it easy on me here, but i thought you just connect the ground wire from the fixture/outlet to the metal box, don't you?

If its a fixture you take the ground wire from the (light) and fasten it to the metal box, and if you are going from a 2 prong outlet to a 3 prong outlet you buy some green wire and connect the green screw on the outlet to the metal box with green wire.

I thought it was that simple. and i thought that's what his question was but boy i'm seeing all these GFI replies and i'm doubting myself now.


You can do that if you have a proper grounding path to the main panel. If you have metallic conduit (like emt) or bx (armored cable) with a bonding strip, than you can tie a ground wire to the box. If the box is metal and romex is entering, a ground still needs to be attached to the box.


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