Run two 120v elements off of 240v?

[Michael_Calgary]

Hi there,

Currently I have a two element kettle. Each element is 120v and completely separate from each other. Since I boil in my basement and the location I boil at is very close to the 240v dryer outlet, I want to eliminate having two 120v power cables going to separate circuits in my basement.

So I have seen wiring diagrams for 240v electric elements. Basically, you just put one hot wire on each element connection. (in Canada, that would be the red and the black wires)

I have two questions.

Question 1:
Can I just run the red to one side of element 1, run a "jumper" cable between element 1 and 2 and then run the black wire to the last connection on element 2? (see pic below)

Question 2:
On the wiring diagrams I've seen, It was stated to NOT connect the neutral wire to anything!! I am assuming it is not needed and would be dangerous to have connected in some fashion?

Thank you.

 

[Lax coach]

The correct way to run 120V off a 240V circuit is with one hot and the neutral. So your diagram would look like two copies of your first one, only with the right leg being white on both, and the left leg being black on the second one. Or put another way, one heater gets Red/White, the other gets Black/White

Your second diagram has both elements wired in series, which does provide 120V to both. This will work, but you lose the flexibility of switching the elements separately, if you decide down the road that's something you want. I would run the one extra wire.

 

[Wizard_of_Frobozz]

Your second diagram has both elements wired in series, which does provide 120V to both.

That's only true if the two elements are identical; if they are different sizes, you will get a different voltage drop across each one when they are wired up in series like this.

Electrically, it will work, since resistors in series just add together and the total current through the circuit will be determined by the total resistance and the voltage drop across the entire thing.

This will work, but you lose the flexibility of switching the elements separately, if you decide down the road that's something you want. I would run the one extra wire.

one heater gets Red/White, the other gets Black/White

I do agree with Lax coach that it limits your ability to control each one separately, so unless there is a really compelling reason to avoid running the neutral wire, I would use a 4 conductor cable (red, black, white, & green/ground). Only one power cord going to the heaters, and wired like Lax coach suggests. Just make sure you choose wire that's rated for the max. current.

If your 240V dryer outlet is a 3 prong outlet, then there is no neutral, and you don't have that option. If you have a 4 prong outlet, then you do have a neutral and you can do it as we suggest. Good description here: https://fredsappliance.com/service/3-prong-vs-4-prong-dryer-outlets-whats-the-difference/

 

[Lax coach]

That's only true if the two elements are identical; if they are different sizes, you will get a different voltage drop across each one when they are wired up in series like this.

Thanks for correcting me. It's been a while since I've messed with this stuff and I totally blocked that part out.

 

[Michael_Calgary]

The correct way to run 120V off a 240V circuit is with one hot and the neutral. So your diagram would look like two copies of your first one, only with the right leg being white on both, and the left leg being black on the second one. Or put another way, one heater gets Red/White, the other gets Black/White

Your second diagram has both elements wired in series, which does provide 120V to both. This will work, but you lose the flexibility of switching the elements separately, if you decide down the road that's something you want. I would run the one extra wire.

Hi thx for the reply. Yes, from some diagrams I did read and understand that I could "make" 120v with one hot and one neutral from 240v. But I want to have just one connection to my pot (with a quick connect) and I want to switch it with one double pole 240v switch.

Currently, my two 120v elements boil my 5 gallon batches with a vigorous boil but not overly vigorous. I did buy two element controllers but decided I didn't need to install them as the boil is to my satisfaction.

My electrician brother in-law wired my current pot for me... but he has left the city I live in so I no longer can make him work for free! (Actually... maybe that is why he moved away???) I just want to replace his wiring with a single 240v connection. I'll be reusing the electrical boxes etc., that he installed to keep me safe.

I think I'll try the in series connection.

 

[Michael_Calgary]

Also, both my elements are identical.

 

[Michael_Calgary]

I do agree with Lax coach that it limits your ability to control each one separately, so unless there is a really compelling reason to avoid running the neutral wire, I would use a 4 conductor cable (red, black, white, & green/ground). Only one power cord going to the heaters, and wired like Lax coach suggests. Just make sure you choose wire that's rated for the max. current.

Oh I see... I can still have one cable going to the pot, but I will have the ability to control one or even both of the elements should I find the need to do so.

 

[Michael_Calgary]

Also, each element can share the single neutral wire? And in this setup, I can still use a double pole switch to open/close the circuit?

 

[Wizard_of_Frobozz]

Oh I see... I can still have one cable going to the pot, but I will have the ability to control one or even both of the elements should I find the need to do so.

Yup, you got it! Keep in mind that you do have to have the 4-prong dryer outlet in order to make this work (see my past post - I edited in some additional comments late).

Assuming that your heating elements are 2000W or lower (at 120V), you should be fine using 12 gauge cable. This assumes that you have a breaker or other kind of over current protection sized for 20 amps or less. Breakers protect the wires, so you have to ensure that the breaker is equal or less than the maximum that the wires can handle (12 gauge = 20 amps; 10 gauge = 30 amps; etc)

Also, each element can share the single neutral wire? And in this setup, I can still use a double pole switch to open/close the circuit?

The neutral is common between both heating elements, but because each "hot" wire is 180 degrees out of phase with each other, the two "hot" lines will cancel each other out, and the only current flowing through the neutral wire is anything that might be due to minor resistance differences between the two elements.

As long as the double pole switch is rated for the maximum current that your setup will have, you will be fine.

 

[Michael_Calgary]

Sweet. Ok, I will see what dryer connection type I have. If I have 3 prong dryer connection, I'll be limited to a series connection. If I have a 4 prong dryer connection, I can wire both elements separately using the neutral commonly between them.

 

[Michael_Calgary]

As long as the double pole switch is rated for the maximum current that your setup will have, you will be fine.

I am looking at double pole switch on amazon rated at 30 amps. As I understand, I can use this to open/close the connection for two different circuits. Or, in my case, attach one hot to each side of the switch to kill the power to my kettle.

 

[Wizard_of_Frobozz]

This one?: https://www.amazon.com/dp/B002MPPTBQ/?tag=skimlinks_replacement-20

I use this exact switch as an off switch for my entire panel and it works fine. It should work for you too. The only real downside to what you are thinking is that you can't regulate the power going to the heaters with just this kind of switch. On/Off is basically all the control you have. I would consider something like the Auber EZBoil or Electric Brewing Supply's Unit paired with a SSR so you can control your boil power. It's a whole lot easier...but also a lot more complicated control panel build.

 

[Michael_Calgary]

This one?: https://www.amazon.com/dp/B002MPPTBQ/?tag=skimlinks_replacement-20

I use this exact switch as an off switch for my entire panel and it works fine. It should work for you too. The only real downside to what you are thinking is that you can't regulate the power going to the heaters with just this kind of switch. On/Off is basically all the control you have. I would consider something like the Auber EZBoil or Electric Brewing Supply's Unit paired with a SSR so you can control your boil power. It's a whole lot easier...but also a lot more complicated control panel build.

Yup! that is the switch. I do have two element controllers. What I was thinking is that I will use a 3 gang box. One spot to hold the switch and the other two spots to hold one element controller each.

 

[augiedoggy]

in this setup most people find its ideal to have one element with on/off control and one element connected to a controller to regulate it. you may want to consider a single 240v ulwd element down the road as well since you already have the 240v.. much quicker and less likely to have any possible scorching depending on what you use now.

 

[Michael_Calgary]

in this setup most people find its ideal to have one element with on/off control and one element connected to a controller to regulate it. you may want to consider a single 240v ulwd element down the road as well since you already have the 240v.. much quicker and less likely to have any possible scorching depending on what you use now.

Ya, I wish I had of gone with one of those 240v 5500 watt (or whatever) wavy elements. I went with two 120v 1500 watt ULWD elements as I didn't want to spend money getting getting electrical cable installed or the large $ amount needed for a controller.

The only issue now is that I have 2 holes drilled in my Kettle. So I am stuck with 120v elements. Unless I can somehow plug the other hole.

But yes, this makes sense to control only one element. I see your point. Right now my Kettle does boil quite nice but not near as powerful as when I was using propane. I just wanted to move out of the garage to indoors.

So, I'll get a 2 gang box. One side with the switch and the other side with a single controller.

So will this work? (this is just a topographical representation.. it will just have one 4 conductor cable going from the 2 gang box to one element housing and then a "connector" cable will run from that element housing over to the other element housing)

 

[Lax coach]

The only issue now is that I have 2 holes drilled in my Kettle. So I am stuck with 120v elements. Unless I can somehow plug the other hole.

This is $4:

https://www.brewhardware.com/product_p/tc15bc.htm

 

[Michael_Calgary]

This is $4:

https://www.brewhardware.com/product_p/tc15bc.htm

Thx Lax couch. Unfortunately my kettle does not have tri-lock ports. just holes drilled in the side.

 

[Lax coach]

Thx Lax couch. Unfortunately my kettle does not have tri-lock ports. just holes drilled in the side.

Gotcha.

 

[dinokath]

Thx Lax couch. Unfortunately my kettle does not have tri-lock ports. just holes drilled in the side.

How about this - https://www.brewhardware.com/product_p/plugwl12.htm

 

[Michael_Calgary]

How about this - https://www.brewhardware.com/product_p/plugwl12.htm

Shoot! That would have been nice.. except the holes in my kettle are 1 inch.

I suppose I could just do some thing like this:

https://www.hopgoblin.com/1-NPT-to-1-2-NPT-Bushing-Stainless-Steel-p/be64124.htm

The nut and O-ring seal on my current element will fit that.

and then and then install a 1/2 plug:

https://www.hopgoblin.com/1-2-inch-MPT-Stainless-Steel-Plug-p/be64098.htm

 

[Michael_Calgary]

Also, I just checked, the element controller I currently have IS rated for 240 volt! So I could get one nice wavy 240V element and control it with my controller. Not only that, if I just use one 240v element, I don't need to worry about screwing around with splitting a 240v supply to run two 120v elements... and, I can easily plug the second hole in my kettle. HAPPY DAYS!!!

 

[Lax coach]

NICE!!

 

[Michael_Calgary]

Well here is where I've ended up.
I've got a dedicated water line for my filter and my Counter flow Chiller, I got a small digital thermometer attached to the wort outflow of the chiller to help adjust (flow) chilling temp and of course my element controller. The sink will be replace with a stainless model soon! (and, I've already cleaned the mess on my counter while building all of this as I have to share it with my wife for laundry folding.) My plan to completely take over this room is in full swing!