240/120volt switching RIMS tube

[choirjon]

Next week, I will have a 50amp plug on a 50amp gfci breaker in my garage. I large step closer to electric brewing. For the foreseeable long term, I will brew in a cooler and a keggle. My electrician neighbor (who works for beer) has said that he can create a rims controller that can be switched between 120 and 240. The way I see it is that this would allow me to heat strike water in my cooler at 240, and then brew at 120. Win, win. I do, however have a few questions that I have been unable to find answers to.

1.) Does the Auber PID need to be reset or reprogrammed if I flip a voltage switch during my brew day? Does the PID care about the voltage of the element that it controls.

2.) It seems that guys only run RIMS tubes on 120volts. Is this really the case? Is is just to easy to burn your beer if you have a 5500 watt tube?



Thanks for looking,



Jon

 

[muhteeus]

1. The auber PID should use a 'set' line voltage, 110V should be fine. The switching would probably be from Neutral to Vb(-120V) -> element (e.g. switch the "common" to the element from Neutral (for 110V) to Vb (for 220V). The PID is probably controlling an SSR, which is 8-24VDC. So No and No.
2. I don't really know a ton about RIMS, but I can tell you about Watt density. The element kal uses spreads the heat over a large area compared to other elements. Same wattage, physically larger element. Now, since the volume you are heating is dependent on flow, you could probably adjust your pump output (using a manual valve) to a level that would prevent scorching. I honestly don't see an issue with 100%. From what I have been reading on here, it seems scorching is less of an issue than it is made out to be.

 

[stlbeer]

Regarding using 1 pid for both 120v and 240v RIMS tube - I think it would depend on how you use it. If you use a 5500w element at 120v then you're putting something like 1375w into the system. That's enough to hold temps or to slightly increase the temps for a 10G batch in a reasonable amount of time. Running a 5500w element at 240v has the capacity to easily boil 10G of wort, however, it doesn't really have the capacity to create on-demand sparge water. i.e. it puts a whole lot more power into your system.

When you tune a PID it learns how the temperature gain and loss and how quickly each one occurs. As such, tuning at 120v would create one set of parameters. Then running at 240v would throw the PID off because there's 4 times the power going into the system. It would probably overshoot the temperature by a massive amount while trying to achieve the set point.

Regarding point 2 - I use a 240v/2000w element in my RIMS tube for 10G batches. It works just fine and does not scorch the wort. It is a ULWD element though. Watt density is important because the higher the watt density of the element the more likely you'll scorch your wort. I say more likely because there are folks who do use high density elements and do not scorch their wort. That could be due to faster flow rates of wort through the tube and I think that would present a problem when you end up with a slow moving mash drain.

 

[muhteeus]

Regarding using 1 pid for both 120v and 240v RIMS tube - I think it would depend on how you use it. If you use a 5500w element at 120v then you're putting something like 1375w into the system. That's enough to hold temps or to slightly increase the temps for a 10G batch in a reasonable amount of time. Running a 5500w element at 240v has the capacity to easily boil 10G of wort, however, it doesn't really have the capacity to create on-demand sparge water. i.e. it puts a whole lot more power into your system.

When you tune a PID it learns how the temperature gain and loss and how quickly each one occurs. As such, tuning at 120v would create one set of parameters. Then running at 240v would throw the PID off because there's 4 times the power going into the system. It would probably overshoot the temperature by a massive amount while trying to achieve the set point.

Regarding point 2 - I use a 240v/2000w element in my RIMS tube for 10G batches. It works just fine and does not scorch the wort. It is a ULWD element though. Watt density is important because the higher the watt density of the element the more likely you'll scorch your wort. I say more likely because there are folks who do use high density elements and do not scorch their wort. That could be due to faster flow rates of wort through the tube and I think that would present a problem when you end up with a slow moving mash drain.

He does have a point. You would need to have the PID tuned for each element. You may be able to adjust the Proportional band based on the ratio of 120V Watts to 240V watts. Honestly, I would just keep the 240V element.

 

[choirjon]

Thanks for the replies. So my best way forward balancing my wish for power, and my need to not ruin beer is to select which element...

Smallish 240 volt (3500 watt) LWD run at 240
Large 240 (4500 - 5500) volt ULWD run at 240
Large 240 volt (6000watt) LWD or ULWD run at 120

Really appreciate the quick replies.



Jon

 

[sumbrewindude]

Bobby had a post on here not long ago about use a RIMS tube as both an on-demand sparge setup in addition to a traditional mash heater using a 240 element switched between 120 and 240.

He had a diagram for wiring it up, using a 30A DPDT switch, as well as a video explaining times and issues with programming running the PID.

Really neat stuff, I'd recommend checking it out and deciding if that's the route you want to go.