Heating Element Control

[rad14701]

Yet another rough schematic in an effort to help with dimmer-controller assembly... The ground lead is not shown but should be run from the outlet ground to the lead on the dimmer as well as run to the boiler...

[KG PackRat]

Thanks for the simple diagram Rad. I know newbies posting without reading is frowned upon here so I took the time and ready all 19 pages. I've noticed people are using various elements with different wattage. As I don't have access to 240, I can't go but so high. Would there be any reason I couldn't use 2 2000W elements? If so, would they have to be on seperate curcuits? Thanks.

[rad14701]

Thanks for the simple diagram Rad. I know newbies posting without reading is frowned upon here so I took the time and ready all 19 pages. I've noticed people are using various elements with different wattage. As I don't have access to 240, I can't go but so high. Would there be any reason I couldn't use 2 2000W elements? If so, would they have to be on seperate curcuits? Thanks.

Any two elements running on 120V would have to be on separate circuits if they push beyond 15A draw which is the circuit breaker limit in most homes here in the US... Drawing 2000W requires ~17A (2000W / 120V = 16.666A)... And from a safety standpoint we don't want to run a a circuits maximum rating, especially if other devices are also drawing power...

Now, all that said, the one advantage of running 120V is that we have a greater selection of elements to choose from because you can use 240V elements with 120V, but not the other way around... Therefore, we could use a 240V 4500W element which would yield 1125W @ 120V...If we mix and match elements, on two circuits, we can come up with custom maximum power inputs...

But there is a downside... If we want regulated power then we either need to run elements at full power or have a controller for one or both elements... Most folks running two elements only regulate one element and unplug the unregulated element once the boiler is up to temperature...

I hope this fully answers your questions... If not, ask away and we'll try to fill in the blanks...

[KG PackRat]

So it sounds to me like I should go with a 1500W element (1500W / 120V = 12.5A). They keg I'm using is a 15.5gal sankey (#2 in Decoy's KEG Identification Thread). My washes are usually only 6 gal. I'll have to look back at some older posts to do the math, but I would imagine it'd take quite awhile for 6gal to get up to temp with a single 1500W element.

[rad14701]

So it sounds to me like I should go with a 1500W element (1500W / 120V = 12.5A). They keg I'm using is a 15.5gal sankey (#2 in Decoy's KEG Identification Thread). My washes are usually only 6 gal. I'll have to look back at some older posts to do the math, but I would imagine it'd take quite awhile for 6gal to get up to temp with a single 1500W element.

Roughly, about 90 minutes...

[MuleKicker]

I started out with a 1500w on my 16gal keg. I am the impatient type, takes too damn long to heat up, especially running a 42" reflux collumn on top. Just aint enough heat there. You will be running more than 6 gal some day packrat. trust me.

Hey rad, i know that circuit works well with 110v, but I have never seen a cheap triac setup like that that will handle 12-15 amps on the 220v side. I looked for a triac that sized and came up short, as maybe i dont know what im lookin for.

I got my PWM arduino setup about ready to rock....just a few more parts, just dont want to spend too much now. Hell I dont even know how well its gonna work yet. Bench testing with current programming seems promising, if my theory holds up. Fingers crossed!

[rad14701]

Mulekicker, it's not the triac that's at fault with a 240V design, it's the control circuit... You need additional components whether using a dual time constant design or using a sensitive triac to drive a high power triac, which is essentially what the dimmer circuit is...

I haven't considered, until just thinking of it now, whether driving the control circuit off one leg of 240V would make it possible to drive the triac at the full 240V...

I've seen LM555 + Optoisolator circuits for driving 240V which may be an option...

Looking forward to hearing how your PWM controller works...

[MuleKicker]

Right, I just thought there was alot more to it, cause no one ever talked about it. Driving off of 1 leg is deffinately a good idea. I just wonder how many of us running electric are doing it 220v. Maybe not many so not much chatter/demmand for it? Yeah, im hoping this controller works out too. I plan on making a topic about the build after i know it works. Nothing worse than building up an interesting topic and......the big finish............It doesnt work!

[Dnderhead]

what whould happon if you ran 2 triacs (one each leg) off one controler?

[new guy]

Hey Mulekicker,

Ben reading a little bout those audrinos, what kind of programs do you plan on running? I think you should start that thread real soon. It would be pretty cool to program some temp control, maybe even a turntable for different receivers. Thats way beyond me though. good luck.

[MuleKicker]

NG,
Im a novice to this programming thing. I will be starting a thread soon with what I know and my findings so far.

[new guy]

MK, just picked up the book " Getting Started With Arduino" seems to me like the only way to create a repeatable process, so there is a consistency in our mashes, fermentations and distillations. But being the electronic newbie that I am, I will be following this very closley.

[MuleKicker]

Yeah, thats the book I got. It is the simplest of programs you will be making to do heat control with a SSR. It isnt always about consistancy, sometimes you have to stray off the path to come up with new ideas. I know these controlers have a lot more potential than simple heat control. This is where I will start.

[rad14701]

Just wanted to post a correction here... In a previous post, HERE, I incorrectly stated that the voltage would always read 120V... This is not an accurate statement in all cases... With a dimmer based controller the voltage will not always read 120V due to the components used... Now that I've re-read this topic and recall how busy I was at the time I can see that the post should have been edited... With all of the measurements I've done it was a blatant error on my part... One of those "DOH!" moments...

[LWTCS]

My voltage swings from 118 to 122

[still crazy]

Has anyone tried an Aquastat like you use on a hot water boiler to switch the heating element on and off?

http://www.pexsupply.com/Honeywell-L400 ... -5481000-p

You could set your hi limit to your boiler or tower temp, where ever you installed the probe. Then set the differential at minimum to maintain that temp.
More or less a cycle switch

[Dnderhead]

you answered your own question "it cycles"

[LWTCS]

Cycling input is not preferable.

Constant/steady input regardless of lot-o-input or lil input is best.

[still crazy]

That aquastat has a min 5 degree F differential.
If in the wash of the boiler thats a pretty tight range don't ya think.
I can't imagine that most can keep there boil at that constant a level by manual means.
I do understand that there will be some lag time and from sensing to adjustment.
Do you really keep your boil temp that constant if your reading temp at reflux on top of column thru scrubbers and reflux drip down.

[rad14701]

That aquastat has a min 5 degree F differential.
If in the wash of the boiler thats a pretty tight range don't ya think.
I can't imagine that most can keep there boil at that constant a level by manual means.
I do understand that there will be some lag time and from sensing to adjustment.
Do you really keep your boil temp that constant if your reading temp at reflux on top of column thru scrubbers and reflux drip down.

That 5 degrees really does make a difference... Yes, we keep our temperatures locked on at 172F/78C with a reflux column and that temperature will fluctuate, as well as our product purity, if cycling occurs... That is why some of us go to the trouble of using a diffuser plate when running on an electric stove or hot plate... And that is also why I am currently sourcing components for a boiler with an internal water heater element and triac based controller... The controller is made and just waiting for the new boiler...

[Pamulli]

For the 240 volt circuit, I used Mouser P/N: 74-4SP10
400V .1 uf MET POLY
The description is Vishay/Sprague Ployester Orange Drop Capacitor.
the variable resistor is P/N: 313-2441-500K
The discription is D-Shaft 500K
Tiawan Alpha 24mm Carbon Potentiometer.

Does anyone have an updated parts list for the 240V circuit? These aren't available anymore and I'm not sure what is a suitable substitute.

Thanks

[MuleKicker]

You kinda gotta look at it like driving a car. you push the throttle to get up to speed then back off, and maintain. You dont get to speed and pump your accelerator wide open then closed to maintain cruising speed. So if you had an ammeter on yer boiler circuit, you could see, say......15A to get up to temp, then back down to 3-4A (or whatever suits your setup) not get up to temp and go 15A-0A-15A-0A. Unless your doing that on a dutycycle, many times a second.

[still crazy]

RAD
I will address this to you as it seems like you new boiler is going to similar to mine.
In this I am assuming you are going to the face to face bowl design you had posted elsewhere on the site.
And you have built the controller outlined from your previous post. The 600W rheostat(dimmer) with the triad and other componets.

With that in mind I have a 10L boiler that I want to use a 120v, 2000w heater element in questions are:
1) Is my element over kill should I go 1500W
2) would I be better off with 220V
3) Can you link me to a parts list(in USA) for the build?

I want to keep my options open to reuse these components in a larger boiler for future.

Oh and Lastly did you get my PM on the tig welder available to join your bowls if your going that route?

I'll thank you in advance for any help you can provide

[HookLine]

Strictly speaking, the heat source can cycle, but the duty cycle has to be very short. Zero switching triac modules work very well for our purposes, and they cycle, typically with a duty cycle of 1 second. Much longer than that starts becoming a problem for distilling, especially for reflux columns, in depend on having a very finely balanced thermal equilibrium.

[Pamulli]

Does anyone have any good pictures and instructions on how to replace the potentiometer on a dimmer switch to make it work for the 240V setup? I know 600W was recommended, but is there anything else I need to look for when buying the dimmer? This is the potentiometer I bought, so hopefully it is the right one http://www.mouser.com/ProductDetail/Alp ... Y9hQ%3d%3d

Thanks,

[rad14701]

Pamulli, did you also buy a 75 Ohm 25 Watt resistor...???

[Pamulli]

Pamulli, did you also buy a 75 Ohm 25 Watt resistor...???

Yes, sorry forgot to mention that. The one I got is Mouser # 75-4PSP10.

Thanks

[rad14701]

Pamulli, did you also buy a 75 Ohm 25 Watt resistor...???

Yes, sorry forgot to mention that. The one I got is Mouser # 75-4PSP10.

Thanks

That is a Capacitor, not a Resistor... You need something more like Mouser #284-HS25-75F to reduce the power through the dimmer circuit that drives the high power Triac...

Just to be sure, which diagram are you going by...??? Some of them do suggest a more durable capacitor...

[Pamulli]

Yes I actually have one of those as well...that exact one actually. I was looking at the wrong part when I wrote that down in the previous post. I'm going by Pintoshine's first diagram along with his written instructions for modifying the dimmer for 240V. I understand the diagram (I think), but I'm not so sure about disassembling the dimmer and attaching new parts. I was hoping someone could show me a picture of how that is done.

[still crazy]

Pam
In the post above your potentiometer is rated at .5W the design calls for 600W for the 120 V curcuit. I am not great with electrical stuff but isn't this a tad undersized?