Stc1000 for rims mash pid

[Sepanik1986]

So I was thinking of putting together a rims tube for mashing to maintain temps, and was curious if I could use an stc1000 to turn the element on. I'm planning on using it on 120volt if that helps. I like the idea but I'm only in the juvenile stages of this one

 

[doug293cz]

I wouldn't recommend it. STC-1000 is strictly an on/off controller. It cannot provide proportional power to your heating element. The minimum hysteresis settings IIRC are +/- 0.3˚C (+/- 0.54˚F), so the minimum range for your setpoint is a little over 1˚F. Any time delays due to the response rate of the thermal sensor (a negative temperature coefficient thermistor) will increase the setpoint range. The stock sensor is also not suitable for immersion in hot wort, so you will need to find a waterproof temp probe with the same nominal resistance and Beta as the stock probe. You could put the stock probe in a thermowell, but that will increase the time constant of the temp probe and reduce the accuracy of your setpoint control.

Also, the output relays in STC-1000's are only rated for 10A, so you shouldn't use them to run anything more than a 1000W heating element @ 120V. The relays are also mechanical, and the rapid cycling required for a RIMS application would likely lead to a short lifetime before wear out.

Use a proper PID in conjunction with an SSR. Or, better yet, use an Auber Instruments EZBoil (DSPR120 or DSPR300.) They perform the same function as a PID (plus much more) and are much easier to tune for acceptable performance.

Brew on

 

[Sepanik1986]

I'll have to check that one out. Thanks for the advice.

 

[augiedoggy]

The shortened answer while they can be made to work is An stc is not a pid and will never be a cost effective and functional equivalent replacement for one in this case... Even a $20 knockoff rexc100 is better suited to the task.