Cheap method for throttling and electric element

[gregdech]

I am in the planning stages for making an electric boiler (for 5 gallon batches, 6.5-7 gallon boil volume) and I'm stuck on the control aspects. I am planning on going with 2-1500Wx120V elements (on seperate GFCI circuits) for the boiler. I suspect that one element won't quite be enough for the boil, but that both elements firing full blast will be a little too much. So, I was thinking of running one element full blast and throttling the second element to get the desired boil rate.

So, my question is, what is the simplest way to throttle the second element to control the boil rate? Cost is a major issue and as such I don't really want to invest in a PID/SSR setup at this time. So, does anyone have any simple ideas for throttling the power for a single 1500Wx120V element? Some of the ideas I was considering:

1) Using a kitchen range surface element control (as per CD's OLD Electric Wort Boiler). The local eco-station always has a few dead ranges kicking around that I suspect I could hack out one of the contollers.

2) Using a light dimmer switch. Not sure if these dimmers can handle the amperage (~12.5 A) that these elements will require.

Any thoughts or suggestions? Which of the above 2 ideas is the most likely to work? Are there any other cheap solutions that any of you have come up with to accomplish this task?

Thanks a bunch.

Cheers,

Greg

 

[brewmasterpa]

you would have to use an old coil style range thermistor for this to work if you used an old range control. i dont see why it wouldnt work. they operate off of 220 so you might consider using a 220 element. you could wire 2 of these elements in parallel, they do have varying wattage elements. you could use 2 different size elements such as how an electric water heater works. you can buy those elements at your local ace or other hardware store fairly cheap. there are duty cycle controllers out there that you could buy to vary the output. if you bought 2 220 volt elements of the same rating, and used a 110 volt duty cycle phaser module, you could theoretically run your elements at full duty cycle and attain a 60% output and this would definitely control your heat absorption. just brainstorming though. ive never looked into building a system like this, but just giving ideas for you to possibly build something like this.

 

[The Pol]

I generally use about 3200W of my available 5500W to maintain a boil in my kettle... you will more than likely be able to keep both running full power.

Now, realize that you are talking about using high watt density elements, which I have never seen anyone do in a boil kettle because of the sugars and concerns over scorching wort.

I have some experience with electric.. 3000W will probably be needed to maintain a good boil in an uninsualted kettle... and high watt density elements may not give you desireable results.

 

[ClaudiusB]

if you bought 2 220 volt elements of the same rating, and used a 110 volt duty cycle phaser module, you could theoretically run your elements at full duty cycle and attain a 60% output and this would definitely control your heat absorption. just

25% is the max you can get if you use a 220 V rated element on 110 V.
Simple formula to calculate effective wattage for any applied voltage.

Effective Wattage= Element Wattage * Applied Voltage²/ Rated Voltage²
Example:
Element Wattage: 2000W
Rated Voltage: 220V
Applied Voltage: 110V

110²=12100 / 220²=48400= 0.25 or 25%
Effective wattage= 2000*.25 = 500W

Cheers,
ClaudiusB

 

[Boodlemania]

you need one of these:

 

[The Pol]

Yeah, the red "x" is the key to completing this project

 

[Boodlemania]

ugh! I guess the direct link didn't work. (It was a shot of a Variac, BTW)

 

[brewmasterpa]

im pretty sure that if you disable the 3rd leg of the input to the 110v modulator, that rule would apply, but if you run the commons parallel you should be able to achieve the 60% i referred too. or electrocute yourself, not sure which one.

 

[garretto]

bump. Interested in going electric. I can only use 110v.

 

[The Pol]

What ya wanna know? You can get up to maybe 2000W with 110VAC... but that is high watt density I am sure. What sort of system do you want? RIMS? HERMS? Which? Neither?

 

[garretto]

Is high watt density more prone to scorching wort?
My idea has been to put two water elements into my keggle, which is my HLT and kettle.
From reading around in different threads, it sounds like 2 elements would maybe help to not scorch the wort.
Like I said, 110v is my only option for a long while.
I had an idea similar to the Op's, which is to regulate how many watts the elements put out with some sort of dial or something similar. My reasoning behind this is that it will also help lessen scorching and also be able to adjust to get a good boil.

I'm not really aimming for HERMS or anything like that. More of having at least two heatsticks built into my keggle, with some way of adjusting them so they aren't full bore.

Thanks, and hope this answers some questions for the OP, so it kinda lessens the thread jacking foul.

 

[gregdech]

Thanks for all the responses thus far. garetto, no worries on the thread jack, it sounds as though we are basically thinking along the exact same lines. A few thoughts based on some of the feedback so far and my thoughts:

- It sounds like (according to the Pol) 3000W may not be too much juice for a boil and as such I may not require any means of throttling the elements back.

- My plan was to use this vessel as both an HLT and a boil kettle. I would mount one element permanently and the other would be a heatstick. When used as an HLT, I would have the permanent element running on a RANCO (already have one) and use the heatstick to speed initial heatup. I would collect the first & second runnings (I double batch sparge) in a separate pot. Once the final sparge is added to the mash, I would transfer the pot contents (to the now empty HLT) for the boil. The heatstick would be used along with the permanent element (full blast, no RANCO) for the boil.

- The Pol makes mention of using low OR ultra-low watt density elements to avoid caramelization. I will do my best to find low watt density elements, but I am not that concerned about it. I suspect this is a boogeyman kinda like yeast autolysis and hot-side aeration. I have seen many warnings about caramelization, but not really much mention about actual cases where an electric element caused it to a large degree. Basically I'm not overly worried about this.

At the end of the day, I think that I may just build it without any controls and see what kind of boil I get. If it is too vigorous with a full 3000W then I will come up with a means of throttling it.

Cheers,

Greg

 

[The Pol]

Yeah guys... I run my 5500W element at 65% to maintain a vigorous boil. If I go much less, the boil is noticeably anemic. This ammounts to 3,575 watts... so my opinion 3000W of power in a kettle will not be too much at all.

 

[jkarp]

Is high watt density more prone to scorching wort?
My idea has been to put two water elements into my keggle, which is my HLT and kettle.
From reading around in different threads, it sounds like 2 elements would maybe help to not scorch the wort.
Like I said, 110v is my only option for a long while.

2KW 120V elements absolutely, positively, won't scorch your wort. I've brewed everything from stouts to pilseners to wits in my e-kettle with fantastic results every time.

[ame=http://www.youtube.com/watch?v=EV8t5iBiaEA]YouTube - Red Head Ale boil[/ame]

 

[garretto]

That's good to hear jkarp. Are they full bore or do you have them regulated with a ranco or love or something? And do you have one or two elements? How big of boils are you doin?

Pol: How big of boils are you doing?

 

[The Pol]

I boil 7.5 gallons for 5 gallon batches. I use 5,500W to get the boil rolling, then dial it back to 3,500W to keep it going. I do 90 minute boils and boil off 1.5 gallons/hour.

 

[garretto]

And you have no issue with scorching?
How do you have it hooked up? Are you using a controller of some sort?
I was under the impression that I could wire the element into an extension cord and just run the element full power. Positive to postive, neutral to neutral, negative to negative. Would there be issues with this?

two 2000w elements would be 4000w, which is about what you tone your's down to Pol.

 

[The Pol]

My 5500W element is ultra low watt density... so I dont know what other elements will do. Peoples results with scorching vary.

I have my element wired to a 30A cord, which then plugs into my control panel. The outlet is power with a PID and SSR controlling the current to the element. Elements are only HOT and NEUTRAL, there is no third connection. You have to ground the element to something, I ground mine to my kettle. My element is 240VAC, so it is HOT and HOT... no neutral or ground. The ground runs to the kettle.

You CAN just wire an element to a plug and let er rip... Id say 3000 to 4000 watts would be good for the size of boil that I do, that is where I run mine when the boil gets going.

 

[garretto]

Alright, so is it grounded to your kettle because it screwed into your kettle? Or do you actually have a wire ran to the kettle?

 

[The Pol]

You will have three wires on a 120VAC cord... HOT, NEUTRAL and GROUND... te ground wire needs to lead somewhere, becuase it does not connect to the element, there are only two terminals on the element. Mine screws to the kettle, where my thermocouple is located.

 

[garretto]

Ok I'm trying to digest all of the info. I appreciate all of your help, you have really cleared up a lot of issues I wondered about.
So let me get this straight, the ground wire from your cord comes from the wall, directly to your kettle. That makes sense.
So the white and black wires from the extension cord will attach to the element, and the green will attach to the keg?

 

[garretto]

oh by the way, I was looking thru your photos and saw your cubes. I started doin no chill. The two batches I've done are still fermenting. I'm pretty excited. I added my 5-15min additions into the actual cube instead of boil.

 

[The Pol]

Exactly right about the ground. The hot and the neutral will attach to the element. You will want to protect your connections and yourself by potting them in epoxy.

 

[The Pol]

I am trying to chill and ferment in the "cube"... I do a lot of FH'ing and my 20 minute and under additions that are left, I plan to add at flameout to account for the isomerization in the cube.

 

[garretto]

yea I was planning on epoxying it all.
But the set up we've come up with so far SHOULD get her running? I'll keep reading up about PIDs and SSRs and try to determine how I can work those in.

 

[The Pol]

Yeah, wiring the element and plugging it in will work. If you have 3,000 - 4,000 watts of power you should be pretty good to go with a 7 gallon boil from my experience.

 

[garretto]

Alright, sounds good. Happy I got a basic understanding now.

But yea, I was reading about how you were planning on chilling and fermenting in the same vessel. That is a pretty cool idea. I'm interested in seeing how it turns out.

Thanks again for the help.

 

[The Pol]

No problem, I hope to have a brew in the fermentor in a week or two. I am getting a sight glass together and some silicone tubing as well.

 

[garretto]

Nice... I'm excited to see the difference in aroma with cube hopping. I've got a bourbon vanilla porter and a kolsch goin right now. we'll see how it turns out. I do need to get a hold of some silicone tubing tho.

 

[jkarp]

That's good to hear jkarp. Are they full bore or do you have them regulated with a ranco or love or something? And do you have one or two elements? How big of boils are you doin?

One element, running full bore for boil. I'm a small batch brewer so I never start with more than 5 gallons. The element is SSR controlled during recirc. This kettle is now part of a counter-top Brutus 20 system.