Electric Brewing Setup

[Clinton]

Over the past 2 weeks or so I have been looking at making my system fully electric. My proposed setup is as follows:

3000W Element from Ebay, $22 USD with free shipping. According to my calculations, it comes under the Ultra Low Watt Density designation, so it won't scorch the wort. I have also looked at the Camco 3500W ULWD Element from Amazon, which is what I have seen many other brewers using. However, it is around two times the price of the element on Ebay. I have checked my circuit breakers, and all of the wall socket circuits are rated for 20A, so I should be fine there.

To control the element, I intend to construct a box with a standard 3 pin input, leading to a PID, which will control an SSR that will switch the current going to a male IEC socket. Here are some pictures of something similar:

As you can see, the output used in this box is a female socket, which leaves exposed pins, which is not good.

I have done some reading up on the PIDs, and it seems that the cheap Ebay PIDs are not worth the hassle, as they will have compatibility issues with both the temperature probes I intend to use, and they will not natively control an SSR. Many brewers recommend the 'Auber' brand PIDs. These are more expensive, but seem to have less issues. They also have manual control over output, which means you can control boil intensity. The model I am looking at is the SYL-2352.

 

I think any SSR will do, as long as it is 15A or over and is capable of handling 250V. Is there any downfalls to using a 40A SSR when a 25A SSR would do fine, such as lower efficiency, etc? There are hundreds of SSRs for sale on Ebay, most of them are the same as the one in the picture above. They're only $5 or so, so that's no big deal.

 

I will probably use a PT100 temperature probe, which has three wires coming from it. Could a 3.5mm jack be used for quick swapping of probes?

So, does this seem like a good setup? Anything wrong here?

Lastly, if I do go through with this, I will most likely be ordering an Auber PID. If anyone would like to order one with me, we could split the shipping costs. Thanks in advance for any help.

[Vesku]

I think so, but you will lose some torque. The heat sink on this one seems to be a little under sized, it runs pretty hot under 3kW load...

[mattd2]

Yeah I got one on order to trial as a speed control. The drill is less than 0.5 kW but it might be dumping a bit of power so could still heat up the sink a bit.

I have seen a circuit using a triac and a diac which apparent gives a better speed control, since the back EMF is sued to sense the speed and thus ups the power if the motor is loaded and slows down - so that should give better control of torque instead of just power (which I guess is what this one does more).

I have to wait for my birthday to get it (I can only swing brewery related stuff twice a year!), but by the 30th I should have it hooked up and trialed.

[mattd2]

Here is one of the example speed (not power) control circuits http://electroschematics.com/444/motor-speed-regulator-with-triac/

But this would require more work than a couple of clicks on ebay!

[Vesku]

I think I made one like this for one of my 1st diy - electric jobs ever, almost 20 years ago. SHIT, time goes fast....

And it was for a drill. I didn't add any heat sink to it so that I could fit it  inside the drill. It failed when I was using it to screw a diy speaker together...all part already glued. My life story really ;)

Buy one without the metal frame, there's no threads or anything that can be used for mounting it to anything....

[Vesku]

The best way to control AC motors is to control the frequency, but that's not a simple/cheap thing to do.

This one seems to be a basic diac + triac, it's reducing the duty cycle of the sine wave.

The funny thing is that, to buy the parts from ebay (never mind from local sources) costs more that the whole setup. How long can this go on?

[mattd2]

Would a VFD be apropriote for a AC/DC universial motor though? And does the ebay unit have a diac aswell or is it a simple power chopper circuit?

Too late to get it without the frame, it is on the boat over! I'll be looking at mounting it in a junction box on a cord so I could still use it for my small BIAB setup if needed, at the moment I don't use it much because the 2.2 kW kettle element is a bit too rough for a full 17 ltr pot!

[Clinton]

Would it be necessary to upgrade the heatsink? I think I have some thermal paste lying around, and I could probably grab something off ebay to suit. Is the unit safe as is?

[Vesku]

I used it for a boil today with 3kW heating element. No issues with the original heat sink, it's running pretty hot, but seems to be holding the smoke inside the triac. It's very handy for step-less boil insensitivity control.

It's as safe as this sort of things are. No place to connect the earth on the case though. There seems to be an opto-isolator for the potentiometer to prevent mains getting in to it, if something fails.

Matt2, There's a diac, it's needed for the triggering.

An easy way to reduce power from heating elements is to put a diode in series with it. It cuts half of the sine wave off.

[Nick T]

I have added a simmerstat to my kettle system but it is on the wall on a box that I plug the kettle into. Just got it from the local electrical supplier, a part for a hobb. Haven't yet commissioned the new brewery so can't tell you how it goes. (Out of curiosity, what is the best way to attach things to a SS kettle? I want to mount some sort of cover over the element attachment points).

[Vesku]

I had a quick look at the simmerstat's on TM and they all seem to be only 15A or so. Did you have 4kW element? If so, that's over 15A.

For the element cover, I drilled holes on the element's flange and threaded those and used them to fix the enclosure on top of the element. I've water heater element that has enough room for the job.

[Nick T]

Its only just over 15A though. I can't recall which model I got now, but I actually have 2 No 2kW elements, so I have the simmerstat on one only (I am pretty sure, it was a while ago I wired it up). 

[Chris Banks]

My experiments with using simmerstats to control temps in a kettle have revealed they are rather coarse in thier control patterns so when used to control an element directly immersed in the liquid they tend to be a bit on/off without the heatsink/storage effect of an element heating through the exterior of a cooking pot as you get on a domestic stovetop for example.

In an Hlt situation they are a little easier to work with - once you have dialled in a temperature and a particular volume of liquid and the corresponding simmerstat setting they should be accurate within a couple of degrees+- but changes in volume require anything but linear changes in settings but Im sure you could nail it down after a few brews.

If your anything like me the experimental/acedemic side of learning about how a simmerstat works is good fun (especially if you get the parts for nout) but only up to a point after that it becomes a little tedious I got to the point where I would rather be tweaking the valve on a burner!

For my two cents at the end of the day you can do the calculations yourself via experiment to come up with simmerstat settings or just let a PID do it for you while your mowing the lawns or cleaning your fermenters ..

Cost wise Im sure a new imported PID,sensor and SSR  and a new simmerstat witin NZ would come out roughly the same cost wise?

Hey sorry Nick not trying to put you of just sharing my thoughts - very interested to know how your thoughts compare to mine once you get yours up and going!

Cheers

Chris