GFCIs in series?

[Keith Ruehl]

Is it permissable to install GFCIs in series?
If so, are there any restrictions as to their locations? For example, may one be located in the garage and another in the master bathroom?

 

[roger]

Why would you want to?

Roger

 

[480sparky]

No rule against it, but as Roger said, "Why?"

Unless you mean is it OK to have more than one GFI on a circuit. If you don't line-load the first one, then any 'downstream' receps that are required to be protected must have a GFI. This is a design issue, and some people like to install a lot of GFIs to make it easy to find the one that trips.

 

[Mule]

I would take the time and take them out and pigtail connections where you dont have to do this....Ive had service calls where this was done, and they were acting funky....pigtailed connections and no more problems...

 

[480sparky]

Is it permissable to install GFCIs in series?
If so, are there any restrictions as to their locations? For example, may one be located in the garage and another in the master bathroom?

After reading the OPs queston again.... the answer is NO. At least when it comes to the bathroom recep. 210.11(C)(3).

 

[Keith Ruehl]

Good question...

Good question...

Why? is exactly the question I asked.
Saw it on an inspection. Could not get an answer as to why it was done that way.

Thanks for your quick replies.
Best wishes.

 

[rabtrfld]

Wrong -- can't test them

Wrong -- can't test them

There may be no rule against it, but it is technically wrong because you can not test the devices.

Every GFCI that I have ever seen has "test monthly" embossed right on the front of it. With units daisy-chained you can not test them, therefore they are not installed in accordance with the manufacturers instructions.

If you press the downstream test button, any unit in the chain may trip. There is no way to control or predict this. This prevents positive testing of the downstream unit.

The test button connects a resistor from line to ground. This will work even if the electronic package is fried. If one of the upstream units trips, you have no way of knowing if the downstream unit is fried or not.

 

[480sparky]

There may be no rule against it, but it is technically wrong because you can not test the devices.
......
The test button connects a resistor from line to ground. This will work even if the electronic package is fried. If one of the upstream units trips, you have no way of knowing if the downstream unit is fried or not.

But it's still GFI-protected.....:wink:

 

[don_resqcapt19]

There may be no rule against it, but it is technically wrong because you can not test the devices.

Every GFCI that I have ever seen has "test monthly" embossed right on the front of it. With units daisy-chained you can not test them, therefore they are not installed in accordance with the manufacturers instructions.

If you press the downstream test button, any unit in the chain may trip. There is no way to control or predict this. This prevents positive testing of the downstream unit.

The test button connects a resistor from line to ground. This will work even if the electronic package is fried. If one of the upstream units trips, you have no way of knowing if the downstream unit is fried or not.

That is not how the test button works on a GFCI receptacle. The test botton on one will not show a ground fault to any upstream or downstream devices. The test button connects a resistor from the hot on one side of the current sensor to the neutral on the other side of the current sensor. This creates the unbalanced current required to trip the device but does not cause a ground fault that other devices would see.
Note this applies to the built in test button, a plug in GFCI tester does create a ground fault and other devices would see it.

 

[dnem]

If so, are there any restrictions as to their locations?

Circuiting restrictions ? Yes !

For example, may one be located in the garage and another in the master bathroom?

GFCIs, regular plugs, doesn't matter. . No garage plug on the same circuit as a bath plug [210.11(C)(3)]

Is it permissable to install GFCIs in series?

Maybe, it's an AHJ call.

About 2 years ago, we [Medina County Building Department] contacted UL to ask this exact question. . ULs answer was that GFCIs have never been tested in series with each other [GFCIs are tested and approved loaded in series with AFCIs]. . When a product is a tested listed product and is installed outside of its tested perimeters, it is the AHJs decision to accept that product as installed or not accept. . And the writeup could list 110.3(B).

In Medina County Ohio loading a GFCI from a GFCI is not accepted/approved. . Check with your AHJ to see what his call is.

 

[Inspectorcliff]

No rule against it, but as Roger said, "Why?"

Unless you mean is it OK to have more than one GFI on a circuit. If you don't line-load the first one, then any 'downstream' receps that are required to be protected must have a GFI. This is a design issue, and some people like to install a lot of GFIs to make it easy to find the one that trips.

This is ok, until they become wired incorrectly, and when one trips,they all trip. Which I have seen happen.

 

[Inspectorcliff]

True

True

That is not how the test button works on a GFCI receptacle. The test botton on one will not show a ground fault to any upstream or downstream devices. The test button connects a resistor from the hot on one side of the current sensor to the neutral on the other side of the current sensor. This creates the unbalanced current required to trip the device but does not cause a ground fault that other devices would see.
Note this applies to the built in test button, a plug in GFCI tester does create a ground fault and other devices would see it.

and they do see it, and often you have to play hide and seek to find which recept has tripped.

 

[Inspectorcliff]

Circuiting restrictions ? Yes !



GFCIs, regular plugs, doesn't matter. . No garage plug on the same circuit as a bath plug [210.11(C)(3)]



Maybe, it's an AHJ call.

About 2 years ago, we [Medina County Building Department] contacted UL to ask this exact question. . ULs answer was that GFCIs have never been tested in series with each other [GFCIs are tested and approved loaded in series with AFCIs]. . When a product is a tested listed product and is installed outside of its tested perimeters, it is the AHJs decision to accept that product as installed or not accept. . And the writeup could list 110.3(B).

In Medina County Ohio loading a GFCI from a GFCI is not accepted/approved. . Check with your AHJ to see what his call is.

David, I have visited one county, that requires a gfci recep in each bath outlet location, even if you run them all off of the same 20 amp. OCD. Go figure.

 

[480sparky]

This is ok, until they become wired incorrectly, and when one trips,they all trip. Which I have seen happen.

No.. what I meant was if you have a circuit that has several receps that are required to be GFI-protected (like all the bath receps, all receps in a garage or unfinished basement, etc.) and don't want to line-load the first GFI, then all the others must have GFIs as well.

Some electricians prefer this method as it's easier for a homeowner to locate the tripped GFI by simply following the cord to the receptacle.

If I had a GFI in a garage or basement that protected half a dozen exterior receps, someone who trips that GFI may find it time-consuming to locate it.

 

[480sparky]

and they do see it, and often you have to play hide and seek to find which recept has tripped.

What Don is saying is that a GFI receptacle creates a ground-fault by using the hot and neutral, not the hot and ground. If it used the ground, how does it work if there's no ground present in the circuit? It has to use the neutral.

Plug-in testers, however, must use the ground to test.

 

[Inspectorcliff]

line line, load line something.

line line, load line something.

No.. what I meant was if you have a circuit that has several receps that are required to be GFI-protected (like all the bath receps, all receps in a garage or unfinished basement, etc.) and don't want to line-load the first GFI, then all the others must have GFIs as well.

Some electricians prefer this method as it's easier for a homeowner to locate the tripped GFI by simply following the cord to the receptacle.

If I had a GFI in a garage or basement that protected half a dozen exterior receps, someone who trips that GFI may find it time-consuming to locate it.

Sparky, I agree with this wiring method, My point was when a sparktrician, incorrectly wires, perhaps 3 GFCI outlets and instead of the line to line to line, on these, he line to load and then load to lines the next one, often with the plug tester, one or both or either will trip. How confusing is that??? allot I think.

 

[480sparky]

Sparky, I agree with this wiring method, My point was when a sparktrician, incorrectly wires, perhaps 3 GFCI outlets and instead of the line to line to line, on these, he line to load and then load to lines the next one, often with the plug tester, one or both or either will trip. How confusing is that??? allot I think.

My understanding is, at least with the newest generation of GFIs, that they will not close the circuit and allow power at either the recep or load terminals if they are miswired.

 

[dnem]

David, I have visited one county, that requires a gfci recep in each bath outlet location, even if you run them all off of the same 20 amp. OCD. Go figure.

I'm not talking about a local code or amendment. . Ohio has none allowed. . All rules are state dictated only and electrical is NEC only. . I was talking about inspectors enforcing within the NEC language.

 

[dnem]

No.. what I meant was if you have a circuit that has several receps that are required to be GFI-protected (like all the bath receps, all receps in a garage or unfinished basement, etc.) and don't want to line-load the first GFI, then all the others must have GFIs as well.

I assumed that when the OP said "series" he was talking about line-load. . "Daisy chaining" [with individual whips at each GFCI] isn't putting GFCIs in series. . They're all still in parallel, the route is a "daisy chain" which kinda looks like a series run but electrically it's definitely parallel.

 

[dnem]

Sparky, I agree with this wiring method, My point was when a sparktrician, incorrectly wires, .....

"sparktrician" :grin:

I've never heard that term before and I've got to say that I love it. . Am I assuming the proper definition ?

Sparktrician:
A hack doing electrical work.