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Electric Element and PID Question

PostPosted: Wed Jul 18, 2018 6:59 pm
by gsx913
Hi All,

I've' spent a fair bit of time reading through the forums and I couldn't find a comprehensive answer, so I thought I'd see what the general consensus is.

Electric elements: any concerns with using a Camco 02965 5500w ULWD element in a still? According to the manufacturer the element is made from "high performance nickel-chromium stainless steel alloy" and the base is stainless steel (unlike some other hot water heater elements).

PID controlling an element: I understand that liquid temperature is not a good indicator of whether a still element should be firing or not. Also, from what I've read on the forum, "the only stable way to regulate the temperature of the element is to limit the electrical flow through the element". Certain PIDs (such as the Auber SYL-2352) can be put into a 'manual' mode where you set a cycle time (e.g. 1 second) and then use the controller up and down switches to allocate power to the element on a percentage of that cycle time (e.g. 10% power with a 1 sec cycle time) means the controller will be on for 1/10th of a second, every second (switching handled by a SSR). Is there any reason this couldn't be used effectively to regulate still output? I've noted its use on other distilling forums but given the misinformation that appears to be out there, I thought I should check anyway.

I own this element and PID for brewing and it would be easier (and cheaper) if don't need to buy alternative parts when I'm considering a sill setup, but I want to do it the right (safe) way.

Thanks,

Daniel

Re: Electric Element and PID Question

PostPosted: Wed Jul 18, 2018 8:13 pm
by db1979
G'day mate, I've got no idea but I think this needs to be moved to the electrical section as it will then have the generic electrical disclaimer at the start of the thread. I'm sure a mod will chime in and sort that out soon enough :handgestures-thumbupleft:

Re: Electric Element and PID Question

PostPosted: Wed Jul 18, 2018 8:41 pm
by Sam.
I'm no electrician but I am fairly certain that cycling the power on and off is not a good thing, this is why most people here use an SSR etc to be able to reduce the power input to the element.

5500w element would be fine as long as you have the power circuit to run it :handgestures-thumbupleft:

Re: Electric Element and PID Question

PostPosted: Wed Jul 18, 2018 8:57 pm
by Professor Green
Sam. wrote:5500w element would be fine as long as you have the power circuit to run it :handgestures-thumbupleft:


Indeed. That's 23 Amps @ 240V.

Re: Electric Element and PID Question

PostPosted: Wed Jul 18, 2018 9:41 pm
by gsx913
Sam. wrote:I'm no electrician but I am fairly certain that cycling the power on and off is not a good thing, this is why most people here use an SSR etc to be able to reduce the power input to the element.

5500w element would be fine as long as you have the power circuit to run it :handgestures-thumbupleft:


I've got a 32a outlet so all good there :handgestures-thumbupleft: In regards to cycling the element via a SSR, I believe this is what the PID was designed to do in relay mode. Even when the PID is in automatic mode (where you set the temperature you want and it maintains it) it regulates by cycling on and off in conjunction with a SSR-rather than by reducing the current--to ensure a stable temperature.

I'm thinking the same cycling logic in manual mode would be similar to reducing the current to ensure the right speed of output from the still. If the still outputs too fast, reduce the time it is on, much like you would if you were reducing the current that went to the element.

Re: Electric Element and PID Question

PostPosted: Wed Jul 18, 2018 10:33 pm
by EziTasting
Not a sparky, but turning an electrical item On and Off repeatedly, be it fast or slow, would wear it out so very much faster!!

My limited understanding is that THAT is the reason most build a ‘Volt-Controlled’ controller... please correct me if I am wrong.

Re: Electric Element and PID Question

PostPosted: Thu Jul 19, 2018 7:47 am
by Professor Green
Auber do a "zero crossing" controller that limits the number of cycles in every 100 cycles the element receives rather than chopping the cycles as with phase angle controllers or switching the element on and off for periods of time like PIDs do. If that is the one you're looking at then it will be suitable.

Re: Electric Element and PID Question

PostPosted: Thu Jul 19, 2018 8:21 pm
by gsx913
Professor Green wrote:Auber do a "zero crossing" controller that limits the number of cycles in every 100 cycles the element receives rather than chopping the cycles as with phase angle controllers or switching the element on and off for periods of time like PIDs do. If that is the one you're looking at then it will be suitable.


Interesting. Thanks for that. I noted they also do a distillery controller which can control the amount of power going to an element in a linear fashion. Thanks everyone!

Re: Electric Element and PID Question

PostPosted: Fri Jul 20, 2018 7:13 am
by warramungas
Sutronics used to do a burst fire controller that did exactly that. Switch on and off.

Re: Electric Element and PID Question

PostPosted: Sun Oct 14, 2018 9:21 am
by mako
This one works great.
10000W High Power SCR BTA10 Electronic Voltage Regulator Speed Controller.
Search ebay - very cheap.