Questions about outside outlet

[Jerry Bruette]

1. Is there a limit on how far away an outlet can be from the GFCI that controls it?

2. If I want to put the outlet on a post how far above grade does the box have to be?

I would like to extend a buried line about 75 feet from a GFCI outlet and mount a weather tight box on a 4x4 post. Is the 75 feet allowable and how far above grade should the box be?

[Paul F Franklin]

There's no code limit as to how far a receptacle can be from a GFCI that controls it, but as a practical matter, you are better off putting a second GFCI at the remote location, so when it trips, you don't have to walk all the way back to reset it. And, no, it doesn't matter if the remote GFCI is connected to the load or line side of the first GFCI, but one would typically connect it to the line side.

There's no code minimum for height above grade for an outdoor receptacle. But keep it high enough so it doesn't get flooded. If you anticipate using it in winter, keep it above typical snow depth.

You will need an "in-use" cover. I find that wasps love to build nests inside the type of in-use cover that has opening on the bottom that are always open, so I use the style that has no openings when it is not actually in use.

75 feet is no issue, but if you see yourself using the outlet for heavy loads like a compressor or larger power tools, I'd probably run 10 ga wire to minimize the voltage drop.

[Cameron Wood]

I agree with Paul above, except for this and the 10 ga comment:

"And, no, it doesn't matter if the remote GFCI is connected to the load or line side of the first GFCI, but one would typically connect it to the line side."

If the remote outlet is connected to the line side of the GFCI, it will not be GFCI protected. I hope this was a typo or something.


I find weatherproof outlets mounted lower than 24" to be super annoying- hard to access.

[Jim Koepke]

I agree with Paul above, except for this and the 10 ga comment:

"And, no, it doesn't matter if the remote GFCI is connected to the load or line side of the first GFCI, but one would typically connect it to the line side."

If the remote outlet is connected to the line side of the GFCI, it will not be GFCI protected. I hope this was a typo or something.


I find weatherproof outlets mounted lower than 24" to be super annoying- hard to access.

I think Paul was saying the receptacle on the extended location should be a GFCI receptacle as opposed to using the current GFCI for protection.

jtk

[glenn bradley]

I would query "the city" if you don't have access to the version of the NEC they are using. My recent build just slipped under the wire or I would have had to add many AFCI outlets and breakers to my shop. Using a GFCI as protection for additional downstream outlets has become pretty restricted around here. If you are going to ignore "code" I would just extend it and move on.

[Jim Becker]

I agree with Paul above, except for this and the 10 ga comment:

"And, no, it doesn't matter if the remote GFCI is connected to the load or line side of the first GFCI, but one would typically connect it to the line side."

If the remote outlet is connected to the line side of the GFCI, it will not be GFCI protected. I hope this was a typo or something.


I find weatherproof outlets mounted lower than 24" to be super annoying- hard to access.

The part you quoted was specifically about the OP putting an actual GFCI at the remote box, so yes, it would be protected with either connection method.

[Charlie Velasquez]

I agree with Paul above, except for this and the 10 ga comment:

"And, no, it doesn't matter if the remote GFCI is connected12 to the load or line side of the first GFCI, but one would typically connect it to the line side."

If the remote outlet is connected to the line side of the GFCI, it will not be GFCI protected. I hope this was a typo or something.


I find weatherproof outlets mounted lower than 24" to be super annoying- hard to access.

Also, whether your extension conductor is gfci protected before or at the the end outlet will affect the method you use to run those conductors.

If the extension conductor is not gfci protected till it gets to the last outlet you will need to bury it 18” in conduit or 24” direct bury (or 6” in rigid conduit, but who would do that for 75’.)
If hooked to the load side of the feeding gfci outlet, you can use uf cable and direct bury it at 12” depth. That may make your job a lot easier.

[Charlie Velasquez]

Additionally, Your conductors must be protected from physical damage, which suggests you will need to have at least a conduit sleeve from below grade to your feeder junction box and another sleeve at your remote box.

Frostline in Peshtigo is… 62” ?
Assuming you are not going to bury your 4x4 that deep. If your conductors and post are not buried to the same depth you may have an issue with differing heave amounts. You will need some way to deal with that; either an expansion fitting on your conduit or a flexible piece of conduit. You almost will assuredly need one at your feeder site if it is on your house.

[Cameron Wood]

OK, that makes more sense, but a GFCI downstream from another GFCI is not good practice- I've seen that malfunction.

[Bill Dufour]

I prefer to mount the master GFCI indoors out of the weather or at least under the house eaves. I had one that got rainwater in and things got rusty. Who knows if it would have worked or not?
Bill D

[Jerry Bruette]

Also, whether your extension conductor is gfci protected before or at the the end outlet will affect the method you use to run those conductors.

If the extension conductor is not gfci protected till it gets to the last outlet you will need to bury it 18” in conduit or 24” direct bury (or 6” in rigid conduit, but who would do that for 75’.)
If hooked to the load side of the feeding gfci outlet, you can use uf cable and direct bury it at 12” depth. That may make your job a lot easier.

Additionally, Your conductors must be protected from physical damage, which suggests you will need to have at least a conduit sleeve from below grade to your feeder junction box and another sleeve at your remote box.

Frostline in Peshtigo is… 62” ?
Assuming you are not going to bury your 4x4 that deep. If your conductors and post are not buried to the same depth you may have an issue with differing heave amounts. You will need some way to deal with that; either an expansion fitting on your conduit or a flexible piece of conduit. You almost will assuredly need one at your feeder site if it is on your house.

Charlie thanks for replying to my question. Here's a poor drawing of what I want to accomplish. I have the conduit and wire purchased and I'd like to go that route in case something goes wrong with the system I can pull new wire. I only have about 3 feet from grade to ledge rock where I want to run the conduit so you're right I won't be burying anything at 62". How deep should I bury the conduit?

IMG_1151.jpg

[Charlie Velasquez]

18”
Assuming thwn conductors?

[Thomas McCurnin]

A GFI breaker in the service panel, when tripped, will of course turn off all outside receptacles governed by the GFI. I find that really annoying, because one cannot determine which receptacle is shorting out. Therefore, put an ordinary breaker in the service panel and a GFI receptacle for each outside line. 75 feet is quite a distance and you will have voltage drop. Going from 12 gauge to an 8 or a 10 would be wise. There are specific calculations for voltage drop which will depend on the amps being sent through the wire and the length. Any qualified electrician will have these tables or they are on line. Your local code will also inform you how deep to bury the lines, but typically that number is around 18-24 inches. I'd put them in the grey pvc schedule 80 and yes, I find having the covered box a couple feet off the ground makes it easier to open the box and insert the plug.

[Jerry Bruette]

18”
Assuming thwn conductors?

Thanks and yup

[Cameron Wood]

A GFI breaker in the service panel, when tripped, will of course turn off all outside receptacles governed by the GFI. I find that really annoying, because one cannot determine which receptacle is shorting out. Therefore, put an ordinary breaker in the service panel and a GFI receptacle for each outside line. 75 feet is quite a distance and you will have voltage drop. Going from 12 gauge to an 8 or a 10 would be wise. There are specific calculations for voltage drop which will depend on the amps being sent through the wire and the length. Any qualified electrician will have these tables or they are on line. Your local code will also inform you how deep to bury the lines, but typically that number is around 18-24 inches. I'd put them in the grey pvc schedule 80 and yes, I find having the covered box a couple feet off the ground makes it easier to open the box and insert the plug.

Many houses, including mine, have 75' or more from the panel to far convenience outlets. How many of them have larger than #12 wire? None, I'd wager.

The OP's use is not mentioned, but standard GFCI recepticals are rated at 15 amps. #8 wire in conduit in earth is rated about 60 amps.

Voltage drop for 75' of #12 wire at 10 amps would be a little over 3%; for #8 wire it would be about 1%.