PID for Boil Question

[JWS]

Alright, I'm getting ready to start setting up my E-HERMS system. Currently I am using propane so slowly buying everything for the electric system. I currently have a 50amp breaker running to my garage for the brewing.

I have a question on PID's for the system. I know I will need to use one for the HLT to get everything up to temp and hold it, but my question is do you actually need a PID for the Boil kettle?

I have seen people talking about dumbing down the power (85% or 65%) on the PID to maintain rolling boil, but I'm wondering couldn't you just run the element full blast?

The only thing I can think of is it will have a higher boil off rate, but as long as you establish that before brewing the first time, then you should be able to get a correct preboil volume to compensate.

I currently do 5 gallon batches in a 15 gallon kettle so I have no worry of boilovers. Could anyone let me know what the disadvantages would be to having the boil kettle element run full blast for the Boil?


Thanks in advance.

 

[slakwhere]

you don't need a PID, a PWM circuit would do the same thing... but you'll want to control it somehow, especially with something like a 4500 or 5500 watt element. you can use the same PID for both functions.

Option 1: use a contactor to switch the output of the pid from outlet 1 (HLT plug) to outlet 2 (BK plug)

Option 2: put a single outlet in the control box and unplug the HLT, plug in the BK.

Option 3: use a PWM circuit