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Max Number Of Receptacles on GFI Protected Circuit?

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Quick question, when installing a GFCI receptacle, is there a maximum number of duplex receptacles you can have after it (protected)? I'm thinking only making sure the load doesn't exceed branch circuit capabilities (20 amps in my case).
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Wow! Never knew this was such a heated topic! This question was for my adolescent health treatment facility. My boss was wanting to have all receptacles in the sleeping areas GFCI protected. I told him the cheapest way would be to install a GFCI receptacle at the beginning of the circuit, thus protecting the outlets after it. Some circuits, according to the prints, serve multiple rooms and hallway receptcales.

That's what drove my question. I knew the 80% load limiting, and the rooms only have clock radios so overloading is not an issue.

Installing GFCI breakers for the circuits would have cost over $7K.
I can’t recall ever seeing a restriction on the number of receptacles that can be supplied downstream of a GFCI receptacle or blank face device, so I reviewed the listed instructions included with the P&S, Leviton, Cooper and some generic brand that I stock for my cheapskate Craigslist customers. They make no reference to such a restriction, so let good wiring practice be your guide here. As noted, excessively long runs can lead to nuisance tripping. I personally feel it’s generally not a good idea to feed receptacles in a different room or common areas downstream from a GFCI receptacle in another room, as it can become chaotic locating the GFCI to reset it if it trips.

I commend your boss for trying to make a safer installation, but if they are not on the specs and no change order approved, don’t cut your own throat.
Will you be using Tamper Resistant receptacles?

For a dwelling unit, let your conscience be your guide as to the number of general purpose receptacle outlets on a branch circuit because there is no NEC limit, but since this sounds like it is a non-dwelling application, 220.14, Branch-Circuit Load Calculations applies for branch circuit receptacle outlet loading, not merely for service and feeder calcs.
Using 220.14, a maximum of 13 receptacle outlets are allowed on a 20A circuit. They can be single or dulpex and still only counts as one receptacle.
The exception would be for simultaneous and non-simultaneous use of receptacles on multi-outlet assemblies [Plugmold] and single piece of equipment with four or more receptacles.
You don’t need to allow for 80% max load on a branch circuit used for these receptacles, the 80% limit is on the receptacle itself. 16A max load on a 20A receptacle, see Table 210.21,B[2]. The 125% [80% max] branch circuit rating your thinking of applies to equipment on individual branch circuits.

Note: using the 2008 NEC for reference.
 

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of course there rated for 15 or 20 amps.. I never said there not....Im just anwsering the question on calculating loads for a recepticle....1.5x12=18...but you should always caluculate at least 1 device to be 1.9 to be safe for a continous load. Im not saying each device is rated 1.5 amps....im saying it should be calculated 1.5amps when calculating a circuit
I don't understand your logic. How do you calculate an unknown load?

Suppose you have a GFI in your garage that feeds 4 outside receps. What is the load on those outside receps? String trmmer? Landscape lighting? Holiday decorations? I've seen outside receps that look like they've never been used. How do you calculate that?

Put the same GFI in a kitchen, and install 2 downstream receps. Now you've got a coffee maker, toaster and micro going all at once.
 

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I don't understand your logic. How do you calculate an unknown load?

Suppose you have a GFI in your garage that feeds 4 outside receps. What is the load on those outside receps? String trmmer? Landscape lighting? Holiday decorations? I've seen outside receps that look like they've never been used. How do you calculate that?

Put the same GFI in a kitchen, and install 2 downstream receps. Now you've got a coffee maker, toaster and micro going all at once.

N.E.C 220.14 I explains my logic
 

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On page 112 of the 2008 code, 220.14 says - other loads---ALL occupancies.

220.14 I
180va (watts) per duplex/triplex or individual single outlet
180 watts/120 volts= 1.5 amps

1.5 amps x 8 recepts = 12 amps max on a 15 amp circuit. This what I am getting at along with man..

Even if outside receptacles cant be counted like 480 said, you still have to account for other recepts on the same circuit.
The code does say max 10 recepts on a 15 amp breaker and 13 on a 20 amp in 220.4 but does not say how many GFCI's.

Next time you open a GFCI box, look to see how many "protected BY" stickers are in there. P & S has 7 stickers. They put the quantity in there for a reason, 1 gfci receptacle and 7 non-gfci receptacles stickers...adding up to 8 receptacles on a gfci.
Why would someone want 40 recepts on a GFCI anyway.

Health care facilities are considered exceptions in 220 and 517 of the code gfci are not always used. Read carefully and save yourself money.

I have really enjoyed this discussion on GFCI's. I like to hear others input and hope others are as open minded as I am.
 

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On page 112 of the 2008 code, 220.14 says - other loads---ALL occupancies.

220.14 I
180va (watts) per duplex/triplex or individual single outlet
180 watts/120 volts= 1.5 amps

1.5 amps x 8 recepts = 12 amps max on a 15 amp circuit. This what I am getting at along with man..

Even if outside receptacles cant be counted like 480 said, you still have to account for other recepts on the same circuit.
The code does say max 10 recepts on a 15 amp breaker and 13 on a 20 amp in 220.4 but does not say how many GFCI's.

Next time you open a GFCI box, look to see how many "protected BY" stickers are in there. P & S has 7 stickers. They put the quantity in there for a reason, 1 gfci receptacle and 7 non-gfci receptacles stickers...adding up to 8 receptacles on a gfci.
Why would someone want 40 recepts on a GFCI anyway.

Health care facilities are considered exceptions in 220 and 517 of the code gfci are not always used. Read carefully and save yourself money.

I have really enjoyed this discussion on GFCI's. I like to hear others input and hope others are as open minded as I am.
You could certainly apply those restrictions to your residential installations if you wanted, but those aren't NEC requirements.
Continue on and read 220.14 [J], Dwelling Occupancies then even 220.16 as well.
For resi, the allowance for general-purpose branch circuit receptacle loads has already been made through the general lighting load calcs done for the service and feeder calcs.
For other than dwelling units, 20A X 120V = 2400W /180VA = 13 maximum receptacle outlets on a 20A circuit. No further calcs or reductions are required.
The NEC states receptacle outlets and makes no differentiation as to the whether they are standard or GFCI receptacle outlets. See 406.3, D[3] about use of those stickers.
There is also no 80% load limitation on a branch circuit used with these receptacles.
The 80% limitation is on the receptacles themselves based on Table 210.21,B[2], which states 16A maximum load on a 20A receptacle.
So, as far as the NEC is concerned, your 20A branch circuit is now already sized at 125% of the maximum load because of this supposed receptacle load limitation, but the NEC makes no differentiation as to continuous or non-continuous loads on receptacle outlets. It states only one value and that is the maximum regardless as to whether the load is plugged in for 10-minutes or 10-years.
In reality though, the NEC is a paper tiger here, because it is impossible to have any real control over what is plugged in after the installation is complete. Presumably manufactures are designing their cord and plug connected equipment within these parameters, but this still doesn’t prevent someone from possibly overloading a receptacle outlet by using an adapter or even a branch circuit by plugging in multiple pieces of equipment into several of these receptacles at once. This is where design issues come into play. :)
 

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The code allows you to load a circuit to 80% of its overcurrent rating and each receptical is counted as 180 Watts' so 15A X 120V = 1800 Watts/.8= 1440 Watts=180= 8 recepticals

20A X 120V = 2400 Watts X .8 = 1920/180 =10.6

Remember these are the minimum requirements I have always use 75% instead of 80.
so, if you had a customer in a home that wanted a new receptacle added in an upstairs bedroom, and the panel is in the basement, and the existing circuit has let's say 10 receptacles and a couple of lights on it but nothing much being plugged into these outlets, are you going to add a new circuit for this? If so then great as long as you have no problem selling this to the homeowner, but I would never even try to do this. I would simply tap off of the existing, as I can sleep knowing that I did the job correctly and didn't overkill it and rip off the HO.
 
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