Question for you electricians

[rockyrude]

The setup:
Where I live residential electrical code is homes are wired from a breaker box to a room with EMT conduit. Inside is a white and a black wire sized for the circuit. The black goes from the breaker to the controlled side of the room ( I'll call this the "hot side", the white ( I'll call this the "low side") is returned from the room to a bar on the breaker box. The third prong of an outlet (ground prong) is normally not connected assuming ground along the conduit. Finally, the breaker box is grounded to the earth through a bar in the ground.

The question:
I ran into a house while wired according the above has two rooms wired with two wire romex. These rooms also use two wire outlets. I want to upgrade to three wire outlets. While I understand not the most ideal, could the third prong be tied to the white side thus grounding the third prong?

 

[bruceb58]

Re: Question for you electricians

No. Don't do that! If the neutral ever opened somewhere, the case of anything you had plugged into that outlet would be hot!

How long ago was that section of the house wired?

 

[bigdee]

Re: Question for you electricians

Bruce is correct.....NEVER use the neutral as the equipment ground.
The easy way out is to install a GFCI receptacle upstream and feed out from of it to the 2-wire receptacles downstream. You don't need a ground for a GFCI to work.

 

[rockyrude]

Re: Question for you electricians

Thanks , I've run into these kind of situations more than I like. This house was built mid 70's and conduit was through out but apparently some yahoo was too lazy to do things correctly in these two rooms. Guess I'll have to brush up on my drywall skills.

 

[bigdee]

Re: Question for you electricians

Thanks , I've run into these kind of situations more than I like. This house was built mid 70's and conduit was through out but apparently some yahoo was too lazy to do things correctly in these two rooms. Guess I'll have to brush up on my drywall skills.

Like I said before, if you do not want to rewire with romex with ground just feed the 2 wire circuit that you have with either a GFCI breaker or receptacle. Putting 3 prong receptacles on an ungrounded circuit is misleading. Code does not require that you have to bring an older house up to code unless you do a remodel but this is a way that you can make it safer with little expense.

 

[rbh]

Re: Question for you electricians

Invest in the little electrical code book (maybe theres one online??), should walk you right through you dilemma.

 

[rockyrude]

Re: Question for you electricians

I know the "right answer" , I was hoping that in my mind that since the neutral and ground are common at the breaker box, I could work around this one.

 

[rbh]

Re: Question for you electricians

I know the "right answer" , I was hoping that in my mind that since the neutral and ground are common at the breaker box, I could work around this one.

UMM, I am not an electrician, "BUT", I am betting thats wrong right there.
Hot to hot and neutral to neutral at the breaker and plug, ground is the only one that should be tied back into the ground bar with the rest of the grounds, this is AC, you get power on both sides.

 

[bigdee]

Re: Question for you electricians

I know the "right answer" , I was hoping that in my mind that since the neutral and ground are common at the breaker box, I could work around this one.

Theoretically your right but as Bruce pointed out the neutral is a current carrying conductor....soooo, if you break it for whatever reason it will have 120 full potential volts on one end! What are your reasons for wanting to ground the receptacles? Do you have devices that have a 3-wire plug that you plan to plug in or are you looking at safety issues? The GFCI will solve the later.

 

[rbh]

Re: Question for you electricians

Theoretically your right but as Bruce pointed out the neutral is a current carrying conductor....soooo, if you break it for whatever reason it will have 120 full potential volts on one end! What are your reasons for wanting to ground the receptacles? Do you have devices that have a 3-wire plug that you plan to plug in or are you looking at safety issues? The GFCI will solve the later.

For a "GROUND FAULT" to work, don't ya need a ground??

 

[rockyrude]

Re: Question for you electricians

Basically it's the three prong plug situation. Since these are normal switched type outlets, adding a GFCI isn't going to work. I don't want to put a three prong outlet on a two wire system since it's the same as cutting the prong off the cord.

 

[HopinImFloatin]

Re: Question for you electricians

while im not an electrician, ive never seen 2 wire romex. should be 2 wire(one black, one white) with bare ground(wrapped in paper). Maybe someone just cut the ground back? Unless its not romex. My 2 cents

 

[bigdee]

Re: Question for you electricians

For a "GROUND FAULT" to work, don't ya need a ground??

No a GFCI does not even need a ground wire to work. A GFCI works by constantly measuring the current in the "hot" conductor and the current in the neutral....they will always be equal and in balance unless the current is being bled off on one side by a fault.

 

[levittownnick]

Re: Question for you electricians

There are other reasons for not using the neutral as a substitute for ground. In some switched circuits (where the fixture (ceiling light for example) has power brought directly to the fixture, a 2-wire (1-black & 1-white) run is brought to a switch. This switch properly has 1-black and 1-white wire connections. That white wire is live (hot-wire). If that white wire were mistaken for a neutral and substituded for ground, anything that were plugged into that "ground" would have the case live and even a GFCI could not interrupt that connection. There are documented situations in which a person has been electrocuted (Death) with just such wiring.
The ground conductor must not be a current carying conductor (except from circuit failure). The white wire is a current carying conductor.

 

[rockyrude]

Re: Question for you electricians

Are you saying that if I replace the two prong outlet with a GFCI problem solved?

 

[bruceb58]

Re: Question for you electricians

UMM, I am not an electrician, "BUT", I am betting thats wrong right there.
Hot to hot and neutral to neutral at the breaker and plug, ground is the only one that should be tied back into the ground bar with the rest of the grounds, this is AC, you get power on both sides.

Ground and neutral are tied together at the circuit breaker box.

 

[dingbat]

Re: Question for you electricians

For a "GROUND FAULT" to work, don't ya need a ground??

yes and no. The device trips on an open circuit, "open" meaning that the current has found and alternative path to ground.

 

[bigdee]

Re: Question for you electricians

Are you saying that if I replace the two prong outlet with a GFCI problem solved?

From a safety stand point,yes. Some sensitive electronic equipment require an "equipment ground" which could be obtained from a good earth ground.

 

[bruceb58]

Re: Question for you electricians

yes and no. The device trips on an open circuit, "open" meaning that the current has found and alternative path to ground.

Not even an open. As little as a few milliamps bleeding off will cause them to trip.

 

[bigdee]

Re: Question for you electricians

I also forgot to mention that this practice feeding ungrounded circuits with a GFCI IS allowed by the NEC as long as you label the ungrounded three prong receptacle with the words "no equipment ground" If it is a 2 prong recptacle you do not have to label it, as it is obvious.