GFCI's in series?
- Thread starter Jon456
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jumper
Senior Member
- Location
- 3 Hr 2 Min from Winged Horses
No electrical problem that I know of.
Not a great design IMO.
Not a great design IMO.
- Location
- Massachusetts
I agree with Jumper.
I agree with both of you. The reason for the question...
There exists some low voltage landscape lighting. Two of the three external transformers are on GFCI's installed near the transformers in weatherproof boxes. There are a number of multi-way switches controlling these transformers, both inside and outside the house. I was thinking of simply installing a GFCI circuit breaker on the branch and calling it a day: it would protect everything. I was wondering if I should also remove the existing GFCI's or just leave them.
There exists some low voltage landscape lighting. Two of the three external transformers are on GFCI's installed near the transformers in weatherproof boxes. There are a number of multi-way switches controlling these transformers, both inside and outside the house. I was thinking of simply installing a GFCI circuit breaker on the branch and calling it a day: it would protect everything. I was wondering if I should also remove the existing GFCI's or just leave them.
I woul just leave them where are you will be better off just leaving them alone.
- Location
- Massachusetts
The problem with putting more equipment on one GFCI is that each thing you add has a bit of leakage current and that starts to take away some of the 'headroom' you would normally have.
As an extreme example: If you had 6 items that each had 1 mA of leakage current they would all work fine with each on a dedicated GFCI. But run all 6 of them through one GFCI and the total of 6mA might trip the GFCI immediately.
The other issue is if it does start tripping troubleshooting it becomes more difficult.
As an extreme example: If you had 6 items that each had 1 mA of leakage current they would all work fine with each on a dedicated GFCI. But run all 6 of them through one GFCI and the total of 6mA might trip the GFCI immediately.
The other issue is if it does start tripping troubleshooting it becomes more difficult.
Jim W in Tampa
Senior Member
- Location
- Tampa Florida
No NEC issues but very bad design because you will go crazy trying to reset them and as said leakage adds up. My advice is don't fix it if it is not broke.
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
Are the gfci recep. fed thru or just controlling each particular trany? If that is the case I would rather see that then see them as feed thru. Of course, I would probably change the hook up to not be fed thru.
Ok, I'll give more detail...
One circuit is low-voltage lighting of area 1. Two transformers. Power runs from breaker #8, to a number of multi-way switches (starting inside, then going to outside switches), to external GFCI receptacle, to both external transformers (on the load terminals of the GFCI).
One circuit is low-voltage lighting of area 2. Two transformers (I misspoke earlier when I said one; I forgot about the second, in-ground transformer). Power runs from same breaker #8 above, to a number of multi-way switches (starting inside, then going to outside switches), to both external transformers (no GFCI).
I was going to replace breaker #8 with a GFCI breaker.
One circuit is low-voltage lighting of area 1. Two transformers. Power runs from breaker #8, to a number of multi-way switches (starting inside, then going to outside switches), to external GFCI receptacle, to both external transformers (on the load terminals of the GFCI).
One circuit is low-voltage lighting of area 2. Two transformers (I misspoke earlier when I said one; I forgot about the second, in-ground transformer). Power runs from same breaker #8 above, to a number of multi-way switches (starting inside, then going to outside switches), to both external transformers (no GFCI).
I was going to replace breaker #8 with a GFCI breaker.
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
Heck I would just add one GFCI to cover the tranies in your second description. The inground trany does not need GFCI protection unless it plugs in-- I have not seen any that plug in.
Ok, but that requires adding another weatherproof box & cover, plus conduit. I thought adding the GFCI breaker would be simpler and less expensive. I had also been advised that, for circuits outside the house, a GFCI breaker inside is preferable to a GFCI device outside because internal corrosion can eventually cause the GFCI protection circuitry to fail.
But I can see the issue about cumulative leakage causing false trips.
I realize the inground transformer is in a sealed "can", but I would have thought a GFCI would be required to protect against any shorting from the high-voltage primary to the low-voltage secondary.
jxofaltrds
Inspector Mike®
- Location
- Mike P. Columbus Ohio
- Occupation
- ESI, PI, RBO
Go to http://www.leviton.com/OA_HTML/ibeCCtpItmDspRte.jsp?item=606332§ion=11625&minisite=10021
"DO NOT install the GFCI receptacle in an
electrical box containing (a) more than four (4)
wires (not including the grounding wires) or
(b) cables with more than two (2) wires (not
including the grounding wire). Contact a
qualified electrician if either (a) or (b) are true."
Click on the instruction sheet link.
Now read step 6. Is it saying no more than two cables in a box?
If so this is a new one to me.
Do they mean a single gang only?
"DO NOT install the GFCI receptacle in an
electrical box containing (a) more than four (4)
wires (not including the grounding wires) or
(b) cables with more than two (2) wires (not
including the grounding wire). Contact a
qualified electrician if either (a) or (b) are true."
Click on the instruction sheet link.
Now read step 6. Is it saying no more than two cables in a box?
If so this is a new one to me.
Do they mean a single gang only?
You must not read that as you would the NEC. These instructions are basically "Installing GFCI's for Dummies". They are intended to walk a layman through the process of installing a GFCI without an electrician. That is why they say: " Contact a qualified electrician if either (a) or (b) are true." Leviton's concern is that if there are more than four CCC's present, then the layman won't be able to properly identify the purpose of the wires and won't be able to connect the GFCI correctly. Section 6 is NOT a restriction on the device; it is merely a restriction on the untrained installer.
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
Why can't you replace the receptacle that feeds the above ground trany? Is that direct wired? If so no GFCI is required on that either. GFCI is to protect people from plugging into the outlet with equipment that may have leakage and cause problems. Generally if there is no cord and plug then a GFCI is not req.
All the transformers are direct-wired. Two come off a single GFCI (direct-wired from the load terminals); two are direct-wired with no GFCI protection.
Why does the absence of a cord and plug make a device immune from leakage? Can't the direct-wired transformer be just as dangerous as, say, a plug-in portable radio? I realize the portable corded device can be dropped into a puddle. But from some of the messy wiring I've seen, I'd be equally worried about a bare hot line wire inside that transformer box, touching against one of the low voltage lines. In other words, I've never seen faulty wiring inside a factory-produced corded device, but I've seen LOTS of faulty wiring inside devices wired by "professional" electricians.
IMO, even if not required, I'd feel a whole lot better knowing there's a GFCI on those transfomers.
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
You can install a gfci wherever you want but the code does not require it in those instances.
Note the articles states receptacles.
Note the articles states receptacles.
- Location
- Massachusetts
I agree with your thoughts but unfortunately UL says all included instructions are part of the listing and labeling meaning that 110.3(B) makes it an NEC issue.
I realize that, but this is the fault of the manufacturer for being unclear. Leviton needs to re-write their instruction book, because it's pretty unambiguous (to me at least) that they are not prohibiting the GFCI from ever being installed in any box with more than "four (4) wires". If that was their intent, then why would they tell the layperson to stop and contact a qualified electrician?
Surely the GFCI doesn't care if there are additional wires passing through the same junction box in which it's installed. It couldn't be an EMF issue because Leviton didn't mention anything about the energized state of any extra wires. For example, if there was 14-3 NM cable, and the red wire was not connected at either end, then a literal interpretation of the instructions would prevent you from installing a GFCI in that box because of the presence of that evil "cable with more than two (2) wires".
Btw, what is the "qualified electrician" supposed to do when the layman calls him? Leviton provided no additional instructions for the pro to follow to resolve the situation.
I understand your point, and I had a feeling someone would call me out on this interpretation, but I think we all know what these instructions are trying to accomplish. I like to be a stickler on the code, but this may be going overboard.
jxofaltrds
Inspector Mike®
- Location
- Mike P. Columbus Ohio
- Occupation
- ESI, PI, RBO
Maybe they have a higher cube rating for this device????
Like I said this is news to me. I was curious if others would turn down an application with more than the '2 cables'.
We all now how hard it is to install a GFCI in a single gang box.
Calling the electrician, I assume, is so that the electrician can change the wiring so as to make the installation conform with the instructions. Like making the box a two gang or adding another box.
Like I said this is news to me. I was curious if others would turn down an application with more than the '2 cables'.
We all now how hard it is to install a GFCI in a single gang box.
Calling the electrician, I assume, is so that the electrician can change the wiring so as to make the installation conform with the instructions. Like making the box a two gang or adding another box.
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