Electric element temperature controller

[thommo]

evening everyone, I've purchased a 3kw heater for my keggle I shall be building
I'm looking to build a controller which will work that will be able to read the temperature and turn the element on or off accordingly.

I built something similar sometime ago for the fermentation fridge using an stc-1000
But read that it would be no good for an element of that power (3kw running on 240v)

Has anyone built something that would work .

Thanks

 

[cegan09]

Plenty of people have built controllers. You can't use something like an STC-1000 because that's not the right application. Temp controllers like that are meant to switch power on and off with large time delays in between. What you need is a PID controller that runs through a solid state relay and is able to switch the element on and off very very quickly.

You can buy controller kits from a number of sources, or you can piece one together yourself. If you are not confident working with high power electricity it is very much advised that you buy a pre-assembled controller, or pre-designed kit.

 

[doug293cz]

Here's a simple design you can build yourself.

This is about as simple as you can go safely. Adding pump control only adds a little more comlexity. You can obviously get much more sophisticated if you have a multi-vessel system, or want extra functions.

Brew on

 

[gnef]

I bought a basic temperature controller that switches an SSR for my 5.5kw element. I only wanted to put in 3 wires into the mini panel (I did a small panel for the HLT and a separate one for the BK using the still dragon SSVR kit), so I found a 220v basic controller, got a 220v ac switching and powering SSR rated for 40 amps mounted on a heatsink, and also got a 220v fan to provide ventilation into the mini panel. I did use strain reliefs for the 10 gauge power cord. I also use a 30 amp wall switch from the sub panel rather than a contactor inside the controller panel.

For me, I didn't see the need for a PID, but that would provide you with a more accurate temperature for your water. I also have the temperature sensor in a thermowell. I do get some drift - when the element turns off, it drifts up by about 2 degrees. I am also pump circulating during this time, as stratification around the element with no agitation was huge for my setup.

Here is a picture of my setup:

Here was a picture when I was testing and assembling things together (I replaced that SSR with a different one later):

 

[augiedoggy]

If this is for a boil kettle and you dont want to use the still dragon ssvr setup (which works well). If you want to be able to achieve a steady consistent boil you need a pid or controller with manual duty cycle like a mypin TD4-snr or inkbird ivh 106 if your on a budget which can be found for like $25-30. otherwise your boil will constantly stop and start and you cant dial in a boil off rate or as effectively even boil off the dms. the auber ezboil has a lot more features but is also a lot more complex to get down as far as menu structure in my opinion. I used it for a few months and still found myself fighting with remembering what was what and trying to decipher directions.