PWM on primary only during boil

[jimhiggs]

I have two separate elements. Primary and Secondary.
I am using the secondary element for mash stage driven by an SSR (so that it can use PWM).
I use primary and secondary elements for boil. My primary element is on a relay just on or off.
I want to be able to set a % PWM during boil but I only want it to affect the element on the SSR, not the one on the relay. Is this possible?

If not I could combine both elements as primary and run them both off the SSR.
Combined my elements are only 2400W with a 40L capacity so I may not need to run at less than 100% during boil.

[frank-nobrega]

Sounds like you already done some wiring on that S40 to bypass the controller it comes with. So that machine has two heating elements like the G30? One small one for mashing and one larger for the boil (both power on for the boil I assume). If so, you might want to wire it up like the old G30 system which is what I have. On those systems the is a rocker switch on the base of the system that lets you toggle the large element on or off. There is only on power cord for the heaters and another one for the pump. I have the pump on a small relay but use an SSR for the heat because PID control will cycle that quite frequently and a relay wouldn't last very long under those conditions. So wire the one power cord to the SSR and wire it so that the smaller element is always on and the larger one comes on only when you flip the switch. I just brewed today and it is pretty well automated with Brewpiless, I flip the switch when it is time to raise the temp to mashout because the small element would take forever to raise the temp that much. I have a 110v system and I have to have PWM at boil set to 100% but it is adjustable in the settings. Once you get everything set up and dialed in you will love it.

[jimhiggs]

I have the system built but am now ready to install it into the S40. Yes the S40 has a switch to turn off one element, but both elements are powered by individual relays in the S40.
I am trying to leave it so it works as standard when the new controller is not plugged in so existing wiring is left as is. One idea was to use the relay to short the two elements when the auto box is powered up rather than use it to switch on the 2nd element. The SSR would then be driving both elements (it would need a bigger heatsink). The relay switch could go to the live side of the second element switch which would then work like yours, or directly to the second element in which case both would be controlled by the SSR, even when mashing. Brewmaniac does a great job of controlling multiple elements though and with the way I have it now, once plugged in the auto box controls both elements with no need to do any switching on the S40.
It would be nice if one of the elements could be switched to no pid/pwm then this one could be just switched on automatically when the boil step is activated. Like you say you don't want rapid switching on relays. It may already be possible I just cant see anything in settings. Maybe something in config files.

[jimhiggs]

Here is my circuit
SCH1.pdf