Hello all,
I built a small temperature controller for my electric smoker using a Shelly 1 relay with the Temperature Add-on module. It has 110VAC input and relay-switched 110VAC output. My smoker plugs into the controller output and all three of the temperature probes go into my smoker. I installed the Generic Thermostat helper, using one of the temperature probe as my sensor and the relay as my switched output. I adjusted the setpoint temperature to 150F and ran it.
The heater stays turned on until the setpoint is reached and then shuts off. But rather staying off until the temperature drops below the setpoint, it continues to periodically cycle on/off driving the temperature higher and higher, never dropping below the setpoint. I aborted the process when the smoker hit almost 200F.
I expected there to be some overshoot and ringing of the temperature because of the on/off nature of the heater control, but this is a different problem. Somehow the relay is getting another trigger to turn on. I thought it might be caused by one of the other two temperature probes, but all three are in the smoker reading the same temperature.
Any ideas?
thanks,
Karl