Double pole (230v) GFI for outside?

[slackdaddy1]

For those that have your compressors outside, in a shed or with just a lean-to. Are you running a double pole GFI?
I plan on the compressor in the shed 10' away from the shop, wire will be buried. 230 will kill you just like 120v,, I know the double ploe GFI is ~90.00 bucks,,, but seams like a bad idea running it outside, under ground and in a shed without the GFI protection?

Slack

 

[FMC1959]

First off, try posting in the electrical section, you might get more responses.
https://www.garagejournal.com/forum/forumdisplay.php?f=30

If you mean gfi breakers, I got some a few years ago for pool equipment in my shed, I don't remember it being that expensive.

 

[Dagny]

I wouldn't worry about it.

 

[slackdaddy1]

I never noticed we had an electrical sub forum,, now I do
Yeah, the SQ D double pole GFCI's are ~100.00

First off, try posting in the electrical section, you might get more responses.
https://www.garagejournal.com/forum/forumdisplay.php?f=30

If you mean gfi breakers, I got some a few years ago for pool equipment in my shed, I don't remember it being that expensive.

 

[dthor68]

It is difficult to answer a question like that without knowing a lot more about what is going on. If the compressor is in a dry, watertight spot, there is no need to use a GFCI breaker. Those breakers can be very sensitive. Pay attention to the amp rating on the compressor and run the right gauge wire. Use the proper breaker for that gauge of wire. If the shed is a good distance away, run a larger gauge wire/with proper breaker. make sure you use either a direct burial cable or conduit/pvc and dig deep enough.

 

[wyliesdiesels]

Whats the HP rating on the comp?

 

[cgrutt]

Not an electrician but personally I wouldn't use a GFI breaker on a direct-wired 220v compressor. I would ground the motor frame and tank though. I did use a 220v GFI breaker in a hot tub that I used to own though, LOL... Believe the requirements for GFI in garage/wet locations are for protection against shock from use of extension cords and equipment where the electric connection is being held by user.

 

[Norcal]

Unless you contact both legs of a 240 volt circuit your only getting hit by 120 volts, but a GFCI is not required in the OP's application by the NEC, nor is it needed.

 

[dthor68]

Unless you contact both legs of a 240 volt circuit your only getting hit by 120 volts, but a GFCI is not required in the OP's application by the NEC, nor is it needed.

I did lighting work for a couple years in Bilo's throughout SC and Ga. I was frequently bit by 230 volt ballest. It is not the voltage that kills you. Lets not forget about all of the people who live through a lightning strike (250,000 volts). What kills is the amperage. One leg of that 50 amp stove or 30 amp dryer can kill you.

 

[wyliesdiesels]

Unless you contact both legs of a 240 volt circuit your only getting hit by 120 volts, but a GFCI is not required in the OP's application by the NEC, nor is it needed.

I agree.

Its not needed

 

[teamextreme]

I did lighting work for a couple years in Bilo's throughout SC and Ga. I was frequently bit by 230 volt ballest. It is not the voltage that kills you. Lets not forget about all of the people who live through a lightning strike (250,000 volts). What kills is the amperage. One leg of that 50 amp stove or 30 amp dryer can kill you.

While all true, Norcal was only pointing out that just because you get shocked from a 240v circuit, doesn't necessarily mean you're getting shocked with "240v".

 

[dthor68]

While all true, Norcal was only pointing out that just because you get shocked from a 240v circuit, doesn't necessarily mean you're getting shocked with "240v".

Yeah, I know. I was just pointing out that voltage should not be your concern.

 

[wyliesdiesels]

Yeah, I know. I was just pointing out that voltage should not be your concern.

Theres a long thread about this.

It went back and forth between voltage and current being the deadly one.

Interesting read...

 

[alfredeneuman]

While all true, Norcal was only pointing out that just because you get shocked from a 240v circuit, doesn't necessarily mean you're getting shocked with "240v".

I've had wannabee electricians tell me "the worst thing is to be shocked with 3 phase", which would involve grabbing both hands and "somewhere else on their body" to separate phases simultaneously.

 

[dthor68]

I've had wannabee electricians tell me "the worst thing is to be shocked with 3 phase", which would involve grabbing both hands and "somewhere else on their body" to separate phases simultaneously.

Your comment made me notice a mistake that I made. The ballast were 277 volts, not 230. 277 volts is one of three phases (480 volts). Been a while. No way to get hit with 3 phases at same time without grabbing all three bus bars simultaneously. But, my guess is they meant 277 volts. Much rather grab that 277 volt 20 amp, than one leg (120 volt)#8, 50 amp.

 

[teamextreme]

Much rather grab that 277 volt 20 amp, than one leg (120 volt)#8, 50 amp.

Trust me, you don't. When I was a service electrician years ago, I got shocked more times that I can count. The worst by far was the high voltage secondary on a neon sign transformer. The second worst, a close second, was 277v off some high bay lights in a Price Club (remember those). The larger circuit size, 50A in your example, increases the arc flash risk, but doesn't increase the shock risk.

 

[slackdaddy1]

I do have a double pole 30 AMP GFCI for my Welder outlet, As I commonly use a 20' 6ga ext cord and roll the mig cart into the driveway. It has never caused any problem with any of the welders.

Yes, most likely someone would get shocked from 115v (from 1 leg to earth),, when getting "shocked" from a 230v circuit.

The compressor would be in a wooden "tool" shed that is 10" from the shop,, the cable run from panel in shop to compressor would be about 20-25'
Compressor is a true 5hp, 21.5 running Amps.

Thinking about running 8/3 cable (3 plus grnd) and tapping 115v off one leg and the neutral for a light and outlet

 

[wyliesdiesels]

I've had wannabee electricians tell me "the worst thing is to be shocked with 3 phase", which would involve grabbing both hands and "somewhere else on their body" to separate phases simultaneously.

wannabes or apprentices?

Your comment made me notice a mistake that I made. The ballast were 277 volts, not 230. 277 volts is one of three phases (480 volts). Been a while. No way to get hit with 3 phases at same time without grabbing all three bus bars simultaneously. But, my guess is they meant 277 volts. Much rather grab that 277 volt 20 amp, than one leg (120 volt)#8, 50 amp.

gotta remember ohms law.

The ampacity of the circuit doesnt matter as you wouldnt be getting hit with all 20a or 50a or 100a...

Ive never been shocked by 277 but trust me, it would hurt a whole lot more than 120v....

Trust me, you don't. When I was a service electrician years ago, I got shocked more times that I can count. The worst by far was the high voltage secondary on a neon sign transformer. The second worst, a close second, was 277v off some high bay lights in a Price Club (remember those). The larger circuit size, 50A in your example, increases the arc flash risk, but doesn't increase the shock risk.

exactly

I do have a double pole 30 AMP GFCI for my Welder outlet, As I commonly use a 20' 6ga ext cord and roll the mig cart into the driveway. It has never caused any problem with any of the welders.

Yes, most likely someone would get shocked from 115v (from 1 leg to earth),, when getting "shocked" from a 230v circuit.

The compressor would be in a wooden "tool" shed that is 10" from the shop,, the cable run from panel in shop to compressor would be about 20-25'
Compressor is a true 5hp, 21.5 running Amps.

Thinking about running 8/3 cable (3 plus grnd) and tapping 115v off one leg and the neutral for a light and outlet

That would not be allowed unless you had secondary overcurrent protection for the light and outlet.

BTW, 8/3 NM-b CANNOT be ran outside or underground.

You should run either individual conductors in pipe or UF-b....

If running individual THWN conductors, you can use #10 for 5HP motor...

 

[alfredeneuman]

wannabes or apprentices?

Self proclaimed journeymen no less

 

[wyliesdiesels]

Self proclaimed journeymen no less

Tell them to try it on 480v and see how far they get... And of course Im kidding....

 

[cgrutt]

Thinking about running 8/3 cable (3 plus grnd) and tapping 115v off one leg and the neutral for a light and outlet

I think you'd be better off running a subpanel to the shed with a 220v breaker for the compressor, 20A GFCI for the outlet and 15A breaker for the lights. You should also pull individual wires buried in PVC conduit from the main panel to the subpanel. Again not an electrician but that's how I ran power to my shed (which has four 220v circuits, a bunch of outlets, and lights.

 

[sberry]

You need additional over current protection doing this, cant simply tap it for a recept without adding an additional fuse.

 

[slackdaddy1]

Yeah, I was going to split it off in a mini sub panel with a 15amp breaker.

You need additional over current protection doing this, cant simply tap it for a recept without adding an additional fuse.

 

[alfredeneuman]

Yeah, I was going to split it off in a mini sub panel with a 15amp breaker.

A subpanel, no matter what size, will need a ground rod or 2 driven, attached to the ground bus of the panel (not the neutral)

 

[slackdaddy1]

Thanks for the heads up,, Having my electrician put it in, I will make sure he includes a ground rod,, or actually I believe it is 2 rods 6' apart.

A subpanel, no matter what size, will need a ground rod or 2 driven, attached to the ground bus of the panel (not the neutral)