#10 wire to GFCI outlet?

[KenB]

A little electrical advice, please. I'm using #10 wire for a long 20A circuit in my pole barn. I'd like to protect the downstream outlets by using a GFCI outlet as the first one from the panel. Trouble is, the 20A GFCI device I have seems to be designed to prevent using anything thicker than #12 wire -- the #10 is too thick and won't fit into the quick connect holes or under the screws. What is the trick?

Ken

 

[belvedere]

If the #10 wire really is needed, you may want to use a GFCI breaker. I know they're expensive, but...

 

[rockwithjason]

simple, don't use the stab holes. if the wire you are using is solid then wrap it around the terminals just like a regular outlet. If the wire is stranded you can use some crimp on fork terminals or use some 12 solid and pig tail it. make sure you connect to the line side and not the load side of the gfi.

 

[LoneGunman]

Put a 12 wire tail on the receptacle and wire nut it to the 10 wire. I'd use a deep 1900 box with a single gang mud ring so you have plenty of room. Don't use the quick connects on any device unless it has a screw to keep the wire tight. I can't count the amount of hours I have spent troubleshooting a partial power outage that was caused by a back stabbed device. They are UL listed for that purpose but they have a high failure rate.

 

[Mickey O]

Put a 12 wire tail on the receptacle and wire nut it to the 10 wire. I'd use a deep 1900 box with a single gang mud ring so you have plenty of room. Don't use the quick connects on any device unless it has a screw to keep the wire tight. I can't count the amount of hours I have spent troubleshooting a partial power outage that was caused by a back stabbed device. They are UL listed for that purpose but they have a high failure rate.

The newer outlets will only let you back-stab 14 ga so it shouldn't be an issue, the older ones you could do 12 ga, but I'd never use them.

 

[belvedere]

He said the #10 wouldn't fit under the screws, either.

 

[Mickey O]

He said the #10 wouldn't fit under the screws, either.

As suggested above, attach #12 to the outlet screws pigtailed to the #10.

 

[MrMark]

Put a 12 wire tail on the receptacle and wire nut it to the 10 wire. I'd use a deep 1900 box with a single gang mud ring so you have plenty of room. Don't use the quick connects on any device unless it has a screw to keep the wire tight. I can't count the amount of hours I have spent troubleshooting a partial power outage that was caused by a back stabbed device. They are UL listed for that purpose but they have a high failure rate.

What he said. Only way to do it. What is a 1900 box?

 

[MrMark]

A little electrical advice, please. I'm using #10 wire for a long 20A circuit in my pole barn. I'd like to protect the downstream outlets by using a GFCI outlet as the first one from the panel. Trouble is, the 20A GFCI device I have seems to be designed to prevent using anything thicker than #12 wire -- the #10 is too thick and won't fit into the quick connect holes or under the screws. What is the trick?

Ken

Imagine that. 10 won't fit under the screws! Wonder where we heard that before.

 

[Mickey O]

What he said. Only way to do it. What is a 1900 box?

It's the one bigger than the 1500 box.


It's a 4 x 4 box.


1900 box

1500 box

 

[MrMark]

It's the one bigger than the 1500 box.


It's a 4 x 4 box.

4S deep Box? 4 X 4 X 2 1/8

Never heard it called that. What does the 1900 refer to?

Your box is shallow by the looks of it.

 

[Mickey O]

4S deep Box? 4 X 4 X 2 1/8

Never heard it called that. What does the 1900 refer to?

The box pictured, in all seriousness I'm not really sure, I've heard it was a part number or something, I think the term is more popular in the mid-west and by union electricians and refers basically to a 4 x 4 two device box. I was taught (actually asked, funny story) that when I was young and have always know them as that.

Your box is shallow by the looks of it.

It's just a picture I grabbed off the internet.

 

[mrb]

pigtail #12 to the 10 to connect to the GFCI device. Even if you could cram a 10 into it or under a screw (I question placing a wire under the screw on a gfci with a pressure plate clamping type terminal, I dont think you are supposed to do that), the device is most likely only listed for #14 and #12 wire.

Second, I take it you are using #10 due to distance / voltage drop. You will have nothing but problems putting a GFCI ahead of a long wire run. Take a look at the instructions for a GFCI, they have a max distance for load side wiring.

 

[JBurgess]

Cooper GFCI will accept #10 wire

http://www.cooperwiringdevices.com/productCatalog/pdf/I 2-3.pdf

"Maximum wiring flexibility is provided with 8
separate backwiring holes that accept up to
#10 AWG stranded or solid wire."

 

[Fast Orange]

Just a quick answer to the box terminology-the numbers refer to Raco part numbers.
As for the #10 wiring issue-as long as the breaker for the circuit is a 20 A,pigtailing with #12 is the answer.Since the only reason # 10 is being used is to avoid a voltage drop problem,the foot or so of #12 in the circuit will have minimal,if any effect.

 

[mrb]

Cooper GFCI will accept #10 wire

http://www.cooperwiringdevices.com/productCatalog/pdf/I 2-3.pdf

"Maximum wiring flexibility is provided with 8
separate backwiring holes that accept up to
#10 AWG stranded or solid wire."

cool thanks. (i hate cooper wiring devices, but thats good to know)

 

[MrMark]

pigtail #12 (I question placing a wire under the screw on a gfci with a pressure plate clamping type terminal, I dont think you are supposed to do that), the device is most likely only listed for #14 and #12 wire.

I put it under the screw although it is not as nice to do as a regular outlet without the backwire capability. The screw is not stable until is is cinched down as it floats in a captive nut. Sidewire is definitely permissible, at least with the leviton, as the device is stated to be sidewire and backwire. They give you a strip guage on the back which states "only for backwire."

I wonder about the cheap clamping plates. They don't seem secure to me with solid wire. Stranded, yes.

 

[KenB]

Thanks guys. I really appreciate all the suggestions!


Ken

 

[Stuart in MN]

Cooper GFCI will accept #10 wire

I looked at the Leviton website, and interestingly their residential grade GFCI only has capacity for up to 12 gauge wire. So, it will depend on the brand.

 

[BioHazard]

I looked at the Leviton website, and interestingly their residential grade GFCI only has capacity for up to 12 gauge wire. So, it will depend on the brand.

Yeah, I had the same problem in my shop bathroom with a 20A Leviton industrial grade GFCI. For some reason they wired my bathroom with 10ga at the end of about 40' of 12ga.

I just crimped on a spade terminal and put that under the screw...

 

[sberry]

I would be skeptical of a crimped on terminal on solid wire on a current carrying conductor. Maybe its made just for that?

 

[BioHazard]

I would be skeptical of a crimped on terminal on solid wire on a current carrying conductor. Maybe its made just for that?

Actually it was crimped, soldered, then heat shrunk. I don't know if that's code but I figure if it's good enough for my boat it's good enough for my bathroom... (I do a lot of marine wiring that way)

 

[LoneGunman]

Solid wire is not good enough for your boat or any boat. The constant vibration from wave action and/or the motor will eventually break the wire. Talk to anyone familiar with marine wiring and they will tell you the same thing unless they have a bunch of solid wire they need to get rid of.

Actually it was crimped, soldered, then heat shrunk. I don't know if that's code but I figure if it's good enough for my boat it's good enough for my bathroom... (I do a lot of marine wiring that way)

 

[mrb]

solder does nothing to improve a properly made crimp terminal.

 

[BioHazard]

Talk to anyone familiar with marine wiring and they will tell you the same thing

Well, as someone who is quite familiar with marine wiring, I say BS. There is no one size fits all wiring, that's like saying "anyone who has wired a house will tell you 14ga wire is big enough for most things". Not all areas of a boat are subject to extreme vibration.

solder does nothing to improve a properly made crimp terminal.

Besides plating the entire thing so that no corrosion can ever happen. Not really an issue inside my walls, but it's not hurting anything either. I generally don't trust crimp only connections...seen too many come apart...for the same reason I stay away from wire nuts as much as possible.

That's why marine wire is tinned...and it's available in both solid and stranded.

 

[LoneGunman]

LOL it seems we are going to **** heads on everything tonight. I did a lot of research before I rewired my boat even though I was already an electrician for 17 years, EVERY credible source, online and in person said solid wire is not recommended for boats. Do an easy google search and show me one CREDIBLE source that says solid wire should be used in boats, I can post an easy 20 that say under no circumstances should it be used.

Now maybe you are talking about a 12 foot boat in a lake, well then have at it, any ocean going or large body of water vessel is subject to vibration throughout the boat, again, that is a fact. I also said nothing about "extreme" vibration, I said "vibration". Will it break in six months, probably not but I have seen the result of careless boating numerous times up close, I don't take chances out on the water.

PROPERLY made crimp connections do not come a part, the problems start when someone who is using a non ratcheting crimper has tired hands or weak hands.

Well, as someone who is quite familiar with marine wiring, I say BS. There is no one size fits all wiring, that's like saying "anyone who has wired a house will tell you 14ga wire is big enough for most things". Not all areas of a boat are subject to extreme vibration.


Besides plating the entire thing so that no corrosion can ever happen. Not really an issue inside my walls, but it's not hurting anything either. I generally don't trust crimp only connections...seen too many come apart...for the same reason I stay away from wire nuts as much as possible.

That's why marine wire is tinned...and it's available in both solid and stranded.

 

[BioHazard]

Well, if you read it on the internet it must be true!

"Marine wiring" could be anything from a canoe to a cruise ship. Or something dockside for that matter. Like I said, there is no "one size fits all".

PROPERLY made crimp connections do not come a part, the problems start when someone who is using a non ratcheting crimper has tired hands or weak hands.

Until robots start doing our wiring, there will always be a margin of error. Asking solder vs crimped on a boat forum is like asking Chevy vs Ford on a Dodge forum. It's almost a religion.

 

[LoneGunman]

"Asking solder vs crimped on a boat forum is like asking Chevy vs Ford on a Dodge forum. It's almost a religion. "

That's something we agree on, also like the 9mm vs .45 argument, Glock vs everything else argument ETC