GFCI Protection 240V 3 Wire?

[P-J]

I thought that three wire dryers were wired HHG, not HHN; two hots and an unshielded ground. No neutral.

Clothes dryers are 120V/240V devices. Power supplied to them using a 3 wire power feed are wired as hot, hot and neutral. The wire used at that time appear as you describe but it is actually "two hots and an unshielded neutral"

 

[sandyeggoxj]

Hey PJ, what about a 6-50r. Isn't that receptacle a H-H-G? Can a spa panel be used with a power source like that?

 

[Alt]

Isn't the typical home spa panel a single phase device? Whereas the 6-50R is intended for split phase usage, where each hot serves as the out-of-phase neutral for the other hot. You need to be sure your panel is wired to provide both phases if you are going to use type 6 wiring and connectors, most home panels are not setup that way. Or that is how I understand it.

 

[sandyeggoxj]

I was planning on running my brewery on the welding outlet. That is why I was asking. My welders are usually single phase but use the 6-50 ends. Definitely a different application than brewing though.

 

[P-J]

Hey PJ, what about a 6-50r. Isn't that receptacle a H-H-G? Can a spa panel be used with a power source like that?

That is a 50A outlet and it is not set up like the typical dryer outlet.
It's a completely different ball game. I would not use it.

 

[sandyeggoxj]

Good to know. Thanks.

 

[thirstyutahn]

So wait a minute...am I reading this correctly. I could take my spare 30amp dry outlet that's hot, hot, unshielded neutral, and put a 50 amp spa panel in and wire it as illustrated in the photo and I'd have a safe gfci protected outlet now? This would save me a tremendous amount of time, money and hassle.

I was advised in the past I'd have to run a completely new line directly from my main and couldn't make my spare outlet work.

I would be pretty thrilled if this could work.

 

[P-J]

So wait a minute...am I reading this correctly. I could take my spare 30amp dry outlet that's hot, hot, unshielded neutral, and put a 50 amp spa panel in and wire it as illustrated in the photo and I'd have a safe gfci protected outlet now? This would save me a tremendous amount of time, money and hassle.

I was advised in the past I'd have to run a completely new line directly from my main and couldn't make my spare outlet work.

I would be pretty thrilled if this could work.

IF your outlet is indeed a "spare" dryer outlet - the answer is Yes. Is certainly can be done. Three wire dryer outlets provide 240V and Neutral to the dryer.

 

[sandyeggoxj]

Ok, I have another question. Aren't the Neutral and Ground bonded in the main panel?

 

[ingchr1]

IF your outlet is indeed a "spare" dryer outlet - the answer is Yes. Is certainly be done. Three wire dryer outlets provide 240V and Neutral to the dryer.

and if your three wire dryer outlet is like mine, and many others out there, you may have a ground wire in the box just not connected to anything. Then you can convert it over to 4 wire.

 

[ingchr1]

Ok, I have another question. Aren't the Neutral and Ground bonded in the main panel?

Yes

 

[P-J]

Ok, I have another question. Aren't the Neutral and Ground bonded in the main panel?

Generally yes they are. If you open you panel and look at the wiring you will see that neutral and ground are delivered from 2 separate bus bars. The neutral is the line being delivered from the power company. Ground is developed within your home.

 

[thirstyutahn]

IF your outlet is indeed a "spare" dryer outlet - the answer is Yes. Is certainly be done. Three wire dryer outlets provide 240V and Neutral to the dryer.

Oh man this is great! Thanks PJ!

 

[johnp]

Clothes dryers are 120V/240V devices. Power supplied to them using a 3 wire power feed are wired as hot, hot and neutral. The wire used at that time appear as you describe but it is actually "two hots and an unshielded neutral"

HOLY COW! Finally an answer to a question I posted a year ago. As long as I have it wired like a dryer outlet (its wired to a 2 pole, 30A breaker), I can use this existing wiring for my planned system. Every one in that thread was telling me the bare was a ground, nobody mentioned an un-shielded neutral... Thank you!!

 

[brew_ny]

Ok, I have another question. Aren't the Neutral and Ground bonded in the main panel?

but not bonded in a sub panel as a rule, at a sub panel if I can I like to drive in a ground rod

 

[sandyeggoxj]

HOLY COW! Finally an answer to a question I posted a year ago. As long as I have it wired like a dryer outlet (its wired to a 2 pole, 30A breaker), I can use this existing wiring for my planned system. Every one in that thread was telling me the bare was a ground, nobody mentioned an un-shielded neutral... Thank you!!

Shielded != insulated

 

[sandyeggoxj]

but not bonded in a sub panel as a rule, at a sub panel if I can I like to drive in a ground rod

I have heard that as well. Why is that? Or can you point me towards some reading material? Or even a set of "search terms" on google? I don't mind looking things up and reading on my own but I don't quite know where to start.

 

[brew_ny]

I have heard that as well. Why is that? Or can you point me towards some reading material? Or even a set of "search terms" on google? I don't mind looking things up and reading on my own but I don't quite know where to start.

I believe it is code but not being sparky I am not sure, I have also been told over so many feet from a main panel the sub panel must have a ground rod by code

I drive in a ground rod at a sub panel just because it cannot hurt

not sure what google but I will try to find some info

all the best

S_M

 

[grandequeso]

Sub panel is only required to have grounding electrode (rod, plate, pipe... Depends on what is accepted where you live based on the soil) if it is a detached building.

 

[brew_ny]

Sub panel is only required to have grounding electrode (rod, plate, pipe... Depends on what is accepted where you live based on the soil) if it is a detached building.

all my sub panels are in detached buildings

good to know thank you

S_M

 

[sandyeggoxj]

Thanks guys. Maybe I'll just reading the NEC for fun and see what I pickup.

Also, what would have a shielded neutral?

 

[jeffmeh]

My layman's understanding: If you permanently mount the spa panel, it would be subject to code, and you would not be conforming to code if you were to bond neutral to ground in the spa panel as depicted in the 3-4 wiring diagram. So, that configuration is not ideal, relative to running 4 wires from your main panel, and using 4-4 wiring in the spa panel to use the GFCI.

That said, the 3-4 wiring is safe (as safe as your dryer or range that is configured the same way), and if you make the spa panel a pluggable device (no changes to your house wiring), then it is not subject to code.

Bottom line: If you can, run H-H-N-G from your main panel. If you cannot, and you can run a separate ground to your spa panel, then do it. If neither of approaches are practical (you rent, not in the budget, etc.), then the 3-4 spa panel configuration is a workable solution.

 

[nosnhojm20]

Good lord, thank for dumbing it down. It finally makes sense.


Sent from my iPhone using Home Brew

 

[fhk]

Modern dryers have 4 conductors because they need a neutral for the 120 volt components in the dryer. 240 doesn't need a neutral but should have a grounding conductor. Older dryers have two hot and a grounding conductor,everything was 240 volts.
For heating elements that are 240 volt there is no "neutral" conductor. A grounding conductor is highly recommended for safety!
So, for anything that is strictly 240 volts, only 3 conductors are needed (verify this with your electrician before proceeding).

 

[jeffmeh]

Modern dryers have 4 conductors because they need a neutral for the 120 volt components in the dryer. 240 doesn't need a neutral but should have a grounding conductor. Older dryers have two hot and a grounding conductor,everything was 240 volts.
For heating elements that are 240 volt there is no "neutral" conductor. A grounding conductor is highly recommended for safety!
So, for anything that is strictly 240 volts, only 3 conductors are needed (verify this with your electrician before proceeding).

Actually, I believe the "typical" older dryers had H-H-N, not H-H-G. They needed the neutral because the control circuitry ran at 120v. The neutral was bonded to the dryer chassis with a bonding strap.

 

[fhk]

Could be, so I guess the overall point is that in older units the third wire functions as neutral and ground, in newer units, neutral and grounding are separate. Essentially because (in current grounding theory) you don't want to bond the neutral and grounding at ay point except in the service panel.

 

[bemerritt]

For some reason I am not able to figure out what to do in my situation. Should be simple and just need a quick answer for some piece of mind.

How do I wire a H-H-G to the spa panel?

 

[P-J]

How do I wire a H-H-G to the spa panel?

What is the H-H-G wiring set up for? If it truely H-H-G to the spa panel, you will not have a neutral. So the panel will only serve as a 240V power source. (In my opinion.) Now if it is old wiring and the circuit is set up for a dryer outlet (H-H-N) you will luck out.

P-J

 

[bemerritt]

The wiring is currently setup for an electric car and I am sure that it is H-H-G. The only things this will power are the two elements. So I assume that I just wire the two hots in/out of the spa panel and make sure that the panel is also grounded, does that sound right? Or should I tie the ground into the neutral inside the spa panel?

 

[P-J]

The wiring is currently setup for an electric car and I am sure that it is H-H-G. The only things this will power are the two elements. So I assume that I just wire the two hots in/out of the spa panel and make sure that the panel is also grounded, does that sound right? Or should I tie the ground into the neutral inside the spa panel?

With that set up you do not have a neutral.