My outlets are not grounded
#1
10-27-03, 08:47 PM
My outlets are not grounded
I couldn't find an answer in my electrical book so I'm asking the forum.
Most of the outlet and light switch boxes in my house have only two wires coming into them - a black and a white. The house was built in 1961 and the boxes are metal and there is no ground wire at all. I have a nifty little tester device that I bought at Home Depot and these outlets all read as "open ground" using the tester.
Is this unsafe? Is there a way I can make these outlets and switches safe without re-wiring the entire house? Does attaching a ground wire from the grounding screw (green) on the receptacle to the box make any difference at all?
Most of the outlet and light switch boxes in my house have only two wires coming into them - a black and a white. The house was built in 1961 and the boxes are metal and there is no ground wire at all. I have a nifty little tester device that I bought at Home Depot and these outlets all read as "open ground" using the tester.
Is this unsafe? Is there a way I can make these outlets and switches safe without re-wiring the entire house? Does attaching a ground wire from the grounding screw (green) on the receptacle to the box make any difference at all?
#3
10-27-03, 09:40 PM
Non-metallic.
Please allow me to start over since I just went through my book again. Problem #1 is I think I need a better book, perhaps the Black & Decker one. My book is the Home Depot Wiring 1-2-3. It's helpful but just too basic for most of the situations I come across. Don't get me wrong, the book has helped me immensely with the basics but always leaves me with questions once I embark on a new project. You guys help me out a lot more than the book does. Problem #2 is that I don't think I had a grasp on what exactly grounding means. I understand it more now, having read about it again.
What we have here is metal boxes that are attached to studs and no other metal, and no ground wires. So they can't really be grounded. Is my best option using a GFCI at the beginning of the circuit? I realize now that connecting a ground wire from the ground screw to the box will serve no purpose and will in fact give a false impression that it is grounded when it is indeed not.
Also, what about the light switches? Does it hurt anything if they are not grounded? This all pertains to the living room and 3 bedrooms. I'm not having issues with any other areas of the house at the moment. Bottom line, I want to have correctly wired outlets for safety's sake, if possible.
And the tester device that I referred to in my original post is a yellow receptacle analyzer and I apologize for the layman's terms.
Please allow me to start over since I just went through my book again. Problem #1 is I think I need a better book, perhaps the Black & Decker one. My book is the Home Depot Wiring 1-2-3. It's helpful but just too basic for most of the situations I come across. Don't get me wrong, the book has helped me immensely with the basics but always leaves me with questions once I embark on a new project. You guys help me out a lot more than the book does. Problem #2 is that I don't think I had a grasp on what exactly grounding means. I understand it more now, having read about it again.
What we have here is metal boxes that are attached to studs and no other metal, and no ground wires. So they can't really be grounded. Is my best option using a GFCI at the beginning of the circuit? I realize now that connecting a ground wire from the ground screw to the box will serve no purpose and will in fact give a false impression that it is grounded when it is indeed not.
Also, what about the light switches? Does it hurt anything if they are not grounded? This all pertains to the living room and 3 bedrooms. I'm not having issues with any other areas of the house at the moment. Bottom line, I want to have correctly wired outlets for safety's sake, if possible.
And the tester device that I referred to in my original post is a yellow receptacle analyzer and I apologize for the layman's terms.
#4
10-27-03, 10:21 PM
If you want to use 3 hole recepts the only option without rewire is to gfci at the beginning of a circuit. Sometimes in bedrooms 2 wire is still fine as a lot of stuff only has a 2 wire plug anyway. My parents home is like that, built around the same time, I have just added grounded recepts where needed or on new installs. With plastic switch covers, covered floors and very limited ground potential its not a serious issue in some areas. Bathrooms and kitchen areas need to be gfci and appliances with metal cases, laundry, fridge, micro, etc need grounded circuits. I put furnace on grounded circuit. I think gfci circuits may be great idea if you have little kids around. Certainly couldnt hurt.
#5
10-27-03, 11:05 PM
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MartyMcFly
Yes, you are correct in assuming that connecting the ground wire to the box has absolutely no effect in providing a ground path. I would double check the wiring to see if a ground wire does exist inside the sheathing. If not I believe the only way to ground all the outlets would be to re-wire. I cannot see how a GFCI at the beginning of the circuit will fix things. It is true that having a GFCI should protect you from shock if you touch the hot wire. However, it will not trip if the case of the appliance you connect to the outlet becomes live due to the hot wire touching the case. In this case the case will remain live until you touch it in which case hopefully the GFCI will sense the imbalance in current and trip.
However, there is no way around not having a ground wire if you want your outlets to have this protection. If you had a ground wire, even if you did not have a GFCI, the breaker is likely to trip if there is a short to ground since the overload will be sensed by the breaker. Without a ground the breaker and GFCI will not trip if a short was to occur since there is nowhere for the current to go.
hope this helps.
Yes, you are correct in assuming that connecting the ground wire to the box has absolutely no effect in providing a ground path. I would double check the wiring to see if a ground wire does exist inside the sheathing. If not I believe the only way to ground all the outlets would be to re-wire. I cannot see how a GFCI at the beginning of the circuit will fix things. It is true that having a GFCI should protect you from shock if you touch the hot wire. However, it will not trip if the case of the appliance you connect to the outlet becomes live due to the hot wire touching the case. In this case the case will remain live until you touch it in which case hopefully the GFCI will sense the imbalance in current and trip.
However, there is no way around not having a ground wire if you want your outlets to have this protection. If you had a ground wire, even if you did not have a GFCI, the breaker is likely to trip if there is a short to ground since the overload will be sensed by the breaker. Without a ground the breaker and GFCI will not trip if a short was to occur since there is nowhere for the current to go.
hope this helps.
#7
10-28-03, 07:13 PM
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rav12,
GFCI receptacle do not require a ground to function. In the event that a fault should occur finding some other path to ground (other than the third prong of the recept), such as a incidentally grounded plumbing pipe, the GFCI will offer protection.
GFCI receptacle do not require a ground to function. In the event that a fault should occur finding some other path to ground (other than the third prong of the recept), such as a incidentally grounded plumbing pipe, the GFCI will offer protection.
#8
10-28-03, 08:42 PM
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Sorry – let me clarify my previous post. Yes, I agree – a ground is not required for the GFCI to function. A GFCI will trip if for example a person touches the hot wire on a GFCI protected circuit. In this case, the person provides the current path to ground causing an imbalance in the GFCI and thereby causing it to trip. The ground wire in this case has no effect. On the other hand if we consider an appliance that has a case that becomes live due to a short between the hot wire and the case, the GFCI will not work since there is no ground fault (unless as mentioned the appliance is connected to grounded plumbing or something similar). This will only be true if this was something like a dishwasher or water heater. Unlikely to be the case it if were a radio. So the ground fault will occur when the person touches the appliance.
However, if a ground wire were present the ground fault will hopefully occur via the ground wire before the person touches the appliance and cause the GFCI to trip hopefully before the person touches the appliance. Also if a GFCI were not present it is likely that the breaker would trip due to current overload. I guess what I was trying to say is that while a GFCI will offer some protection in the event that a ground wire does not exist from a safety point of view it would be much better to have the ground wire present, since the ground wire and not the person would conduct the current.
However, if a ground wire were present the ground fault will hopefully occur via the ground wire before the person touches the appliance and cause the GFCI to trip hopefully before the person touches the appliance. Also if a GFCI were not present it is likely that the breaker would trip due to current overload. I guess what I was trying to say is that while a GFCI will offer some protection in the event that a ground wire does not exist from a safety point of view it would be much better to have the ground wire present, since the ground wire and not the person would conduct the current.
