Please help me figure out my 240v plans

[samtriesnottodie]

So I have an old style 3 prong dryer outlet (nema 10-30r) that I want to use for power. My understanding is that this has 2 hots and a neutral wire.

I have purchased a still dragon controller kit -- then reading the instructions I realized they are for a 2 hots and a ground setup. Question 1, is there a way to wire it up with 2 hots and a neutral? My hopefully-not-too-stupid naive assumption is that I would wire the two hots as normal and the neutral as the ground.

My second question is.. there's no way I want to do this without GFCI protection -- I know I could use a circuit breaker switch, but I would prefer inline protection for portability. I found this: 30 Amp Inline GFCI but I'm unsure if this will work if I wire it with 2 hots and a neutral as well.

I plan on using L6-30p/r twist locks for everything after the dryer outlet, but according to the wiring diagram I saw for that, it's supposed to be two hots and a ground, not neutral. This seems like it should work for what I have planned, but I specifically don't know about the GFCI.

Thanks to anyone who can help shed some light on these questions for me... I want to make sure I do this right and safely.

 

[day_trippr]

3 prong is two "hots" and a ground. There is no neutral...

Cheers!

 

[samtriesnottodie]

3 prong is two "hots" and a ground. There is no neutral...

Cheers!

Really? Oh geez. So I just based this on a quick google of "10-30r wiring"... ala Google Image Result for http://waterheatertimer.org/images/3-pole-3-wire-250V-300.jpg

Looking a past the first image result, there's several diagrams that disagree: Google Image Result for http://waterheatertimer.org/images/How-to-wire-outlets-7.-750j.jpg

Thanks for clarifying. I saw that and freaked out that I was going to do something stupid. This is one of those situations where "thinking I have it right" just isn't cutting it for me. The more I've thought about it and googled though, the more I realized that that one non-hot wire going back to the breaker is the same thing, regardless of what it's called. Either way, cheers. Thanks for helping my peace of mind.

 

[day_trippr]

Well you definitely had cause - I've never seen a "non-grounding" 3 wire 240v setup diagram before. And I can't imagine in what jurisdictions that could be legit (definitely none I've owned homes in).

Heck, even 3-wire 240V is being "encouraged out" in favor of full four wire around here. I had an electric range from 1984 replaced last year and had to run four wire to meet current code in NH, and had we not switched to a gas range in our primary home when we totally re-did the kitchen we would have had to do the same...

Cheers!

 

[IslandLizard]

3 prong is two "hots" and a ground. There is no neutral...

Cheers!

Although that's correct, on a dryer all the electronics other than the heating coil, such as the timer, lights, sensors, audible signals, etc. likely run on 120V between one of the Hots and Ground. So the Ground will carry a small current as the "return" conductor.

That used to be totally normal and very acceptable for 50+ years...

Now if you want GFCI protection, there's no choice, you'll need a separate ground and neutral. Using a spa (sub)panel is often the logical choice as it contains the correct GFCI breaker for less money.

 

[samtriesnottodie]

Although that's correct, on a dryer all the electronics other than the heating coil, such as the timer, lights, sensors, audible signals, etc. likely run on 120V between one of the Hots and Ground. So the Ground will carry a small current as the "return" conductor.

That used to be totally normal and very acceptable for 50+ years...

Now if you want GFCI protection, there's no choice, you'll need a separate ground and neutral. Using a spa (sub)panel is often the logical choice as it contains the correct GFCI breaker for less money.

I definitely want GCFI protection -- why won't that inline extension cord I linked earlier work?

 

[Bobby_M]

This GFCI breaker can be jammed into a box along with the SSVR controller kit you bought.

https://www.amazon.com/NDB1L-32C-32...=din+mount+GFCI+breaker&qid=1597797334&sr=8-4
That breaker actually only monitors the L1 and L2 hots, not a neutral and since you won't be using a neutral, you're fine. It can also be used as a power on/off switch.

Even though the dryer was using that 3rd conductor as a Neutral, in 99% of cases it is terminated in the main breaker panel on a shared neutral/ground buss anyway. When you plug into it, that line will be used as a ground.

 

[samtriesnottodie]

This GFCI breaker can be jammed into a box along with the SSVR controller kit you bought.

https://www.amazon.com/NDB1L-32C-32...=din+mount+GFCI+breaker&qid=1597797334&sr=8-4
That breaker actually only monitors the L1 and L2 hots, not a neutral and since you won't be using a neutral, you're fine. It can also be used as a power on/off switch.

Even though the dryer was using that 3rd conductor as a Neutral, in 99% of cases it is terminated in the main breaker panel on a shared neutral/ground buss anyway. When you plug into it, that line will be used as a ground.

Ah cool. Thats sort of what I figured -- since its a dedicated dryer only circuit, and i'll be using it as a dedicated circuit for this, using it as a ground seemed fine.

 

[day_trippr]

Although that's correct, on a dryer all the electronics other than the heating coil, such as the timer, lights, sensors, audible signals, etc. likely run on 120V between one of the Hots and Ground. So the Ground will carry a small current as the "return" conductor. That used to be totally normal and very acceptable for 50+ years...

100% accurate. Hence my comments about having to upgrade our NH house to four-wire due to modern code requirements, which are also current in MA.
I'm ok with it though. A circuit ground should be reserved for safety use only...

Cheers!

 

[samtriesnottodie]

Yeah, upgrading that particular circuit is actually not going to be too bad I hope (blessed with an unfinished basement and most of the wiring in the ceiling of that. I'm like 3 deep in recursive projects at the moment though, so I want to get this all put together before i tackle that. Anyway, I appreciate all the help, I was second guessing a lot of what I was doing and would rather ask a stupid question than electrocute myself or burn my house down.

 

[Willee]

As far as physics goes the neutral and ground go to the same place ... the ground buss bar in your breaker box.
As far as code and regulations go they are different ... go figure.
I would never use a 220v setup up that did not have a ground or neutral wire with it.
The risk is there just waiting to bite you.

 

[MN brewer]

I have a GE box, but this is also compatible with Siemens, this went into my regular box for my dryer outlet set up for my Bleichman tower of power. My neighbor electrical engineer looked at my set up. This works with the two hots and a ground set up and doesn’t require a 4th wire.

https://www.menards.com/main/electr...l2130gftp/p-1464866379487-c-1489583170892.htm

 

[tinoespinosa69]

So I have an old style 3 prong dryer outlet (nema 10-30r) that I want to use for power. My understanding is that this has 2 hots and a neutral wire.

I have purchased a still dragon controller kit -- then reading the instructions I realized they are for a 2 hots and a ground setup. Question 1, is there a way to wire it up with 2 hots and a neutral? My hopefully-not-too-stupid naive assumption is that I would wire the two hots as normal and the neutral as the ground.

My second question is.. there's no way I want to do this without GFCI protection -- I know I could use a circuit breaker switch, but I would prefer inline protection for portability. I found this: 30 Amp Inline GFCI but I'm unsure if this will work if I wire it with 2 hots and a neutral as well.

I plan on using L6-30p/r twist locks for everything after the dryer outlet, but according to the wiring diagram I saw for that, it's supposed to be two hots and a ground, not neutral. This seems like it should work for what I have planned, but I specifically don't know about the GFCI.

Thanks to anyone who can help shed some light on these questions for me... I want to make sure I do this right and safely.

This is the extension cord with GFCI I bought at a really great price (lower than the ones you mentioned). It did include 100' of cable. The only con was the lead time (they are offering 9 days now, but in my case it said 16 days and took 1 month)
https://www.galco.com/buy/Arrow-Hart-Cooper-Wiring-Devices/GFI23A7NN
It is a 3 wire GFCI. You will have to add the plug connector. I used this taking apart the neutral blade.
https://amazon.com/gp/product/B07XBY7JSH/ref=ppx_yo_dt_b_asin_title_o00_s01?ie=UTF8&psc=1
And the 204V receptacle. In my case I used a box for the receptacle, but can can use other types
https://amazon.com/gp/product/B00002NAT9/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1

 

[Bobby_M]

As far as physics goes the neutral and ground go to the same place ... the ground buss bar in your breaker box.
As far as code and regulations go they are different ... go figure.
I would never use a 220v setup up that did not have a ground or neutral wire with it.
The risk is there just waiting to bite you.

No one ever suggested using a circuit that didn't have a ground or neutral. We're talking about using an outlet that has Hot, Hot, Neutral by NEMA receptacle definitions only. When the brewing controller is plugged in, that 3rd wire will be USED as an equipment ground, which offers all the same fault protection that the same conductor labeled "ground" would.

 

[samtriesnottodie]

Yeah, since the only thing on the circuit is going to be the brewing equipment, my plan is just to use the neutral as a ground for the first iteration of this. This, plus an inline gfci.

 

[Bobby_M]

If you want to go really overboard, change out the receptacle for a 6-30R or L6-30R to make it fully legit.