Yet another wiring question

[cgallery]

As long as the new GFI isn't downstream from another GFI, you're good to go.

The GFI outlet has electronics that compare current in the neutral and hot legs. If the difference is more than 4 or 5 milliamps, it trips. The difference might be due to bad tool wiring or current leaking to a puddle of water (through you).

I feel safer with a GFI in a circuit than I do with a grounded outlet. All my extension cords, for my handyman business, are equipped with GFI's.

(1) So, basically you can only have one GFI per circuit, right?

(2) Additional outlets on that circuit have to be non-GFI?

(3) And does the GFI provide any protection to the non-GFI receptacles on the same circuit?

(4) And the non-GFI's on the same circuit, do you ground those?

(5) And, is grounding a GFI optional, or do you just never ground one?

Sorry for all the Q's.

[master53yoda]

(1) So, basically you can only have one GFI per circuit, right?

Yes.

(2) Additional outlets on that circuit have to be non-GFI?

Yes

(3) And does the GFI provide any protection to the non-GFI receptacles on the same circuit?

yes

(4) And the non-GFI's on the same circuit, do you ground those?

no The term here is bonding

(5) And, is grounding a GFI optional, or do you just never ground one?

GFCIs are grounded if a ground is available.

They are good questions

In summary:GFCIs are grounded if a ground is available.
all downstream receptacles are protected by the GFCI,
without the ground you will be limited as to how many downstream receptacles that you can place on the line beyond about 4 or 5 due to capacitive or inductive reactance in the wiring, If the system was grounded the grounding would carry that to earth ground and the GFCI won't see it.

Bonding (or grounding as referred by most of us here) equipment without carrying the bond to earth ground is not a good idea because you can end up with a static charge in the bonding loop that doesn't have any where to go. See the comment about the factory in my prior post.

Hope this answers your questions

[eccentrictinkerer]

(1) So, basically you can only have one GFI per circuit, right?

(2) Additional outlets on that circuit have to be non-GFI?

(3) And does the GFI provide any protection to the non-GFI receptacles on the same circuit?

(4) And the non-GFI's on the same circuit, do you ground those?

(5) And, is grounding a GFI optional, or do you just never ground one?

Sorry for all the Q's.

What master53yoda said!

[cgallery]

Just to clarify, you DO bond the GFI if available, but you DON'T bond any of the other receptacles on the circuit?

[master53yoda]

Just to clarify, you DO bond the GFI if available, but you DON'T bond any of the other receptacles on the circuit?

nope! If there is a bond path back to a earth ground you bond all receptacles both the GFCI and any down stream receptacles the only time you would not bond the downstream receptacles is if the GFCI does not have an earth ground available.

[Mr__Bill]

nope! If there is a bond path back to a earth ground you bond all receptacles both the GFCI and any down stream receptacles the only time you would not bond the downstream receptacles is if the GFCI does not have an earth ground available.

If at the GFCI there is no ground to bond to, do you do anything with the ground wire from the GFCI? I have seen it connected to the common but this does not seem right to me as a ground fault at the GFCI would not be detected, or am I missing something.

If you are wiring new receptacles from the GFCI that has no ground bond what do you do with the ground in the new Romex? At the GFCI and at latter receptacles? Should the latter receptacles be ungrounded 2 slots, or grounded 3 hole types?

Bill

[master53yoda]

If at the GFCI there is no ground to bond to, do you do anything with the ground wire from the GFCI? I have seen it connected to the common but this does not seem right to me as a ground fault at the GFCI would not be detected, or am I missing something.

If you are wiring new receptacles from the GFCI that has no ground bond what do you do with the ground in the new Romex? At the GFCI and at latter receptacles? Should the latter receptacles be ungrounded 2 slots, or grounded 3 hole types?

Bill

If there is no place to connect the ground/bonding wire cut it off and put a wire nut on it.

do not connect the down stream bonding wires. Also the receptacles that are not bonded back to an earth ground need to be identified that they are not grounded. There is some talk in the code world that you not use 3 prong plugs, or fill the ground plug hole with silicon. My personal feeling on this is that IDing them is sufficient, and plugging the hole in would invalidate the UL label.

i have attached some pictures that i have plagiarized off of the net. It was a bit surprising to me how many of the net sites either did not provide all the information needed or information that was completely incorrect.

The first picture shows the connection paths from the main transformer to shorted receptacle, and the return path on the bonding/ground system.

the second picture shows the operation of a GFCI, the only incorrect thing on this picture is that the neutral is opened as well as the power line on most GFCIs.

the third picture shows the proper connection when there is an available ground.

the last picture show correct and incorrect neutral connections when connecting a GFCI to protect the downstream receptacles

I hope this helps

[Mr__Bill]

If there is no place to connect the ground/bonding wire cut it off and put a wire nut on it.

do not connect the down stream bonding wires. Also the receptacles that are not bonded back to an earth ground need to be identified that they are not grounded. There is some talk in the code world that you not use 3 prong plugs, or fill the ground plug hole with silicon. My personal feeling on this is that IDing them is sufficient, and plugging the hole in would invalidate the UL label.
snip
I hope this helps

It makes sense, somehow I had it in my head that the GFCI provided a ground, and couldn't really figure out how. If I understand you correctly the GFCI provides protection for a short to ground where you are the ground or ground path but if you have something that is expecting a real ground it's not there.

Although the GFCI has a ground socket it's not connected to anything, additional receptacles on the load side of the GFCI are protected but have no ground and should be polarized two conductor without ground receptacles, the ground wire in the romex should not be connected to anything.

If three prong plugs have to be used downstream of the first GFCI then the downstream receptacles should also be GFICs and connected to the line and not the load side of the original GFCI and so forth downstream.

Thanks for the pictures and comments, I think I understand it better now.

Bill

[master53yoda]

If three prong plugs have to be used downstream of the first GFCI then the downstream receptacles should also be GFICs and connected to the line and not the load side of the original GFCI and so forth downstream.

.Bill

i think you may have this one not quite right yet. the downstream receptacles are protected by the first GFCI see the second picture of the group. the down stream receptacles are drawing the power through the sensors in the first one and are protected. The ground terminals in the downstream plugs are not connected to anything and do not provide a ground path. the reasoning behind not using the three prong receptacles is simply that you may think you have a ground when you don't, that is why the receptacles are supposed to me marked that they are not grounded.

I want to remind everyone that the only time you don't ground /bond the GFCI circuit is if there is not a grounded bonding path at the GFCI location to start with as in older then mid 1950s houses. many of the 50s houses had wiring run that had the bonding wire but was not connected to the plugs. In those cases I have gone completely through the houses and updated all the receptacles to 3 prong and verified the ground path at all receptacles and updated the service grounding to include ground rods and all water and gas piping. See the first picture.

I also always have installed GFCIs in the bathrooms of any house that I have worked on even if it was Knob a Tube wiring from the 30s.

Good luck in your wiring endeavors and be sure what your doing doesn't have any questions in your mind. If it questions get help.

[Sid]

i think you may have this one not quite right yet. the downstream receptacles are protected by the first GFCI see the second picture of the group. the down stream receptacles are drawing the power through the sensors in the first one and are protected.

See the fourth picture of your earlier post. You described the connections it shows as correct and incorrect, but the text in the picture just says that when the downstream outlets are connected to the line side, rather than the the load side of the GFCI, then the downstream outlets are NOT protected by the upstream GFCI. That's the scheme that Mr_Bill says to use when the downstream outlet is also a GFCI that will be protected only by itself, not by the upstream GFCI. What he says makes sense to me. Why is it "not quite right"?

Sid

[master53yoda]

See the fourth picture of your earlier post. You described the connections it shows as correct and incorrect, but the text in the picture just says that when the downstream outlets are connected to the line side, rather than the the load side of the GFCI, then the downstream outlets are NOT protected by the upstream GFCI. That's the scheme that Mr_Bill says to use when the downstream outlet is also a GFCI that will be protected only by itself, not by the upstream GFCI. What he says makes sense to me. Why is it "not quite right"?

Sid

yes what your saying is correct, but as long as the down stream receptacles are marked as not being grounded there isn't anything gained by using a GFCI at every receptacle.

What I wanted everyone to realize is that the neutral can't be common connected or pigtailed on a GFCI like it can in other applications and still have the downstream receptacles protected.