GFCI receptacles feeding other devices

[LAYMAN JOE]

Im new here and maybe this question has come up before.

How many devices can one GFCI receptacle feed from the load side terminals? This is hugely debated in the field. Many say only three can be protected by one rec.

I dont see anywhere in the code that would limit how many devices a general purpose GFCI rec can feed. As long as the downstream devices current rating is the same as the GFCI, I dont see a problem.

 

[bstoin]

You won't find anything in the NEC concerning this specifically.
I believe (if memory serves) that you may feed 6 outlets downstream...this is found in the listing of the GFCI itself.

 

[LAYMAN JOE]

You won't find anything in the NEC concerning this specifically.
I believe (if memory serves) that you may feed 6 outlets downstream...this is found in the listing of the GFCI itself.

the manufacturers listing? I have looked at different manufacturers to find no limitation.

 

[bstoin]

the manufacturers listing? I have looked at different manufacturers to find no limitation.

I remember some time (years) back looking this up and I believe this was the case. I am sure someone will either verify this or prove me wrong. Either way, I'm sure an answer does exist.

 

[LAYMAN JOE]

indeed an answer does exist. I was thinking this would be a hot subject because its so highly debated in the field.

 

[tallgirl]

indeed an answer does exist. I was thinking this would be a hot subject because its so highly debated in the field.

There's very likely no "official" answer because the limit is based on things that fall outside the code.

The practical limit is based on current leakage between conductors, particularly because hot and ground. When two wires run close to each other there can be capacitive and inductive coupling. As that gets closer to the 5ma limit for GFCIs, the circuit will start to think there is a ground fault and trip.

 

[Dennis Alwon]

How many devices can one GFCI receptacle feed from the load side terminals?

I have never seen a GFCI that limits the number of receptacles on the load side of a GFCI receptacle or breaker for that matter. In all lilkelyhood there is no limit since design of the circuit will usually limit the number anyway.

I have never had a need to put more than 4 or 5 receptacles on a GFCI just because of the way I design my circuits.

 

[gmreynol]

The NEC probably wouldn't tell you the limitations and how a manufacture's product should work, possibly check U.L. I have seen manufactures recommendations in the booklet which comes with the device. The last time I read one it said six, but i agree there could be a many variables. I dont believe there are many quality applications which would call for over six down stream devices fed from a GFCI.

 

[LawnGuyLandSparky]

There's very likely no "official" answer because the limit is based on things that fall outside the code.

The practical limit is based on current leakage between conductors, particularly because hot and ground. When two wires run close to each other there can be capacitive and inductive coupling. As that gets closer to the 5ma limit for GFCIs, the circuit will start to think there is a ground fault and trip.

That would explain limiting the downstream circuit length, but not the number of receptaces.

 

[bstoin]

some answers

some answers

I did a little research online on the subject and here's what I found:

The following excerpt came from the following web-page:
http://ecmweb.com/mag/electric_think_gfci/

...
GFCI installation tips

Again, the best GFCI installations are those where you "think like a GFCI" and lay out the installation to minimize "nuisance tripping." At the same time, you should "think like the owner" and consider the GFCI's location, visibility for monthly testing, and resetting convenience should it trip.

Length of circuit. A GFCI is subjected to tests that simulate long branch circuits. While there are no specific rules concerning the length of the circuit protected or the number of receptacles on the protected circuit, remember that the GFCI will add up all the harmless leakage currents and capacitive leakages. Under extreme circumstances, this could "preload" the GFCI and make it appear overly sensitive or, worst case, result in nuisance tripping. Therefore, you should minimize the length of circuits to the degree possible.

Do not protect some appliances. While the NEC requires a number of receptacles in the kitchen, garage, and basement to be GFCI protected, protection is not required on those serving refrigerators, freezers, or sump pumps. In addition to the obvious reasons of not wanting to interrupt power to these important appliances, some older types of frost-free refrigerators and freezers have relatively high leakage currents when in the defrost cycle. GFCI circuits should be routed so these appliances are not on protected circuits.

The Code requires lighting fixtures and exhaust fans in bathrooms to be grounded, but does not require them to be GFCI protected. Exhaust fans accumulate dust and moisture, possibly increasing leakage levels. Some types of fluorescent fixtures may generate switching transients. This type of equipment should not be wired on the protected portion of the circuit.

 

[LAYMAN JOE]

I just bought a home built in 1956. The branch circuits dont have a GEC. I need to find the first receptacle on a circuit and install a GFCI and then protect the rest of the circuit.

Im lazy and cheap. I hope I dont get nuisance tripps :grin:

On new installations, I have never needed to protect more than 3 rec from 1 GFCI.

 

[LarryFine]

Im lazy and cheap.

If you're lazier than you are cheap, install GFCI breakers instead.

 

[George Stolz]

The branch circuits dont have a GEC.

I think you meant to say "EGC."

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