GFCI Protection 240V 3 Wire?

Brewer's Friend 728
Homebrew Talk - Beer, Wine, Mead, & Cider Brewing Discussion Forum

Help Support Homebrew Talk - Beer, Wine, Mead, & Cider Brewing Discussion Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
sandyeggoxj said:
Ok, I have another question. Aren't the Neutral and Ground bonded in the main panel?
Click to expand...
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.
 
P-J said:
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"
Click to expand...

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!!
 
johnp said:
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!!
Click to expand...

Shielded != insulated
 
brew_ny said:
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
Click to expand...

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.
 
sandyeggoxj said:
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.
Click to expand...

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
 
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.
 
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.
 
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).
 
fhk said:
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).
Click to expand...

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.

dryer-bondingstrap.jpg
 
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.
 
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?
 
bemerritt said:
How do I wire a H-H-G to the spa panel?
Click to expand...
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
 
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?
 
bemerritt said:
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?
Click to expand...
With that set up you do not have a neutral.
 
Ok, so wire the hots in/out of the gfci breaker and I am all set to have my two elements be gfci protected?
 
P-J said:
Yes.
Click to expand...

According to Seimens GFCI wiring datasheet:

Note: A load neutral is not required on the circuit.
However, the white line neutral (pigtail) must be
connected to the panel neutral for the device to
function.

Based on this statement there must be a neutral connection between the panel and the GFCI breaker in order for it to work.
 
jleiii said:
According to Seimens GFCI wiring datasheet:

Note: A load neutral is not required on the circuit.
However, the white line neutral (pigtail) must be
connected to the panel neutral for the device to
function.

Based on this statement there must be a neutral connection between the panel and the GFCI breaker in order for it to work.
Click to expand...
It will function just as well with that connection on the grounding conductor.
 
False a neutral and a ground are different neutral is the return path for the hots to carry unbalanced load so the will have voltage on them.
 
Yes but only at the first means of disconnect never again. A ground touching a neutral week trip a afci breaker. It's considered a fault.
 
scottyb710 said:
False a neutral and a ground are different neutral is the return path for the hots to carry unbalanced load so the will have voltage on them.
Click to expand...

scottyb710 said:
Yes but only at the first means of disconnect never again. A ground touching a neutral week trip a afci breaker. It's considered a fault.
Click to expand...

so if they are indeed bonded in the first disconnect how are they different ?

and yes after a GFCI breaker (220) if you try to use the ground coming from the breaker as a neutral to make 110 it will trip as it should

but as we know 220 needs only two hot legs to work and the ground is an equipment ground

correct ?

all the best

S_M
 
Here's my drunken, nonprofessional take. In a three wire application it's H-H-G. If you use that ground as a nutral from the spa panel to the main panel you should wire it to the nutral strip rather than the ground strip. What code doesn't want is a potential for current at the ground strip in the panel. Could be dangeous for someone messing in th panel.

What did I just sy? :drunk:
 
This is my favorite pointless arguement in the electric brewing world.

It was considered 100% safe for years, the code changed and now its considered unsafe.

I can see both sides, I feel educated in the matter now and as a grown man will make my own decision. Proving you're right on the internet is pointless. There are hundreds of things that endanger our lives everyday, its all calculated risks. Lets all stop playing internet police.

Lets get back to brewing gentleman...some on code safe equipment and some on "unsafe" equipment.
 
scottyb710 said:
.....neutral is the return path for the hots to carry unbalanced load so the will have voltage on them.
Click to expand...
Untrue.

NEC calls the neutral a "grounded conductor" and the ground a "grounding conductor". They are both at a 0 volt potential relative to the ground. If neutral has a voltage of anything other than 0, there is a problem.

The neutral will carry CURRENT while the ground should not, under normal circumstances. Maybe current is what you meant but I'm not sure what the unbalanced load part of that statement even means. Current on the neutral conductor is simply the result of 120VAC circuits, balanced or not.
 
It's manly if you share neutrals or have fluorescent lighting the neutral will have voltage if you hold both neutrals to complete the path it will zap you.
 
scottyb710 said:
It's manly if you share neutrals or have fluorescent lighting the neutral will have voltage if you hold both neutrals to complete the path it will zap you.
Click to expand...

If you hold two neutrals in a closed 120v circuit of course you will get zapped. If you hold a ground in either a properly wired (there is no ground fault), closed 120v or 240v circuit, then you will not. With a 3-wire dryer with neutral tied to the dryer chassis for ground, touching the chassis is in effect holding the ground, which logically seems to be the reason that they changed the code here. With a ground fault, you would get zapped.

I am not an electrician, so if I have this wrong, please use clear facts to educate me. :)
 
That's right the neutral would zap you If it had a load on it from like a light.
 
And yes they changed the code for that reason they didn't want the neutral to be tied to the dryer.
 

Similar threads

B
eBIAB PID Controller Wiring Diagram - Feedback Requested
Replies
14
Views
1K
beerisambrosia
B
P
Is this 240v GFCI working on my setup?
Replies
11
Views
942
mac_1103
mac_1103
David Coy
Power 1 and/or 2 Anvil Foundries at 240 from a 30 amp 240 spa panel
Replies
4
Views
581
David Coy
David Coy
kotamoore23
120/240v DIY PID Controller Help
Replies
17
Views
1K
whoaru99
W
H
240v GFCI breaker vs inline GFCI?
2
Replies
54
Views
3K
Langerz
Langerz
InkBird 300

Latest posts

Back
Top