Johnson(or Ranco) Controllers vs PID for Maintaining Target RIMS Temperature

I know this is an old, tired subject, but it is new to me. Has anyone actually built a RIMS setup using a Johnson type controller, and if so what temperature range where you able to maintain with it? I’ve read that PID controllers provide tighter temperature control than Johnson controllers, but can somebody show me the data? If there is an ExBEERiment or other test results comparing these two using actual performance data, please point me to it. I did a search here and did find this data I am looking for. (I’m aware that the Johnson controller uses an electromechanical relay, versus the PID which is used to control a solid state relay.)
Thanks, and Cheers!

Auburn instruments…
Sneezles61

Probably a spellcheck incident Sneezles. You mean Auber Instruments.

1 Like

I’m looking for test comparison data between a Johnson controller and PID/SSR. I did a search on the Auber Instruments website and got nada.

I’m not getting any responses with actual performance comparison data between a “Johnson” and “PID/SSR” temperature controller, so maybe there is not any. Inkbird offers an Electronic Temperature Controller for $35 (Amazon Prime) that I might play around with. Maximum output load is 1kW at 120V. On initial look it should work for my 120V/2kW element. If nobody produces any test data I might do an ExBEERiment with this unit.

https://www.ink-bird.com/products-temperature-controller-itc308.html

From what I was told several years ago: The relays in the Johnson type temperature controllers aren’t robust enough for the frequent on/off cycles experienced when driving a heating element in a RIMS or HERMS arrangement. You’re much better off with PID/SSRs, etc.

ETA: Technically it would work, but the lifespan of the controller will be disappointing.

That is a very good point. Makes sense. Is there a PID/SSR system out there for under $50?

Doubtful. I don’t even know if you can buy the components for that and DIY.

I found these items that would work for my setup for $60 shipped, not including a box, so I’m estimating all in would be ~$100 for a 25A RIMS heating controller. My element is rated 2kW at 120V so the current would be 16.7A.

However, for now I think I’ll just be the temperature controller myself, man in the loop, by watching the mash temperature and adjusting my propane burner.

90-265V Digital F/C PID Temperature Controller Thermostat TA4-SNR SSR output
https://www.ebay.com/itm/90-265V-Di...er-Thermostat-TA4-SNR-SSR-output/301269919439

D PT100 Temp Sensors 1.5"L,1/2”NPT with Telfon Cable & Detachable Connector
https://www.ebay.com/itm/RTD-PT100-...elfon-Cable-Detachable-Connector/173844497101

25A AC Solid State Relay SSR with Heatsink