Two with One

Want to control 2, 5500w elements with "ONE" Pid.. dont know if its been covered, if so point the way.

Do you mean using the same PID to work both the MLT and boil kettle?

I'm curious if anyone has done a switched RTD probe input. I'd think it would increase the chance of making a mistake, but a good question.

Yes, Both the way i see it 2 SSr and 2 rtd sensors , just detach rtd from HLT plug into boil kettle . The 2 SSr's would be the thing to figure out. Maybe connect both to PID???

Double-R

I'm doing just that with my setup, check out my thread. Simple eHERMS with P-J schematics. Something like that, just to lazy to link since on my phone.

Double-R said:

Want to control 2, 5500w elements with "ONE" Pid.. dont know if its been covered, if so point the way.

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Squeeky's Diagram:

Auberin-wiring1-a4-4500w-30c.jpg
Auberin-wiring1-a4-5500w-30b.jpg

The temp probe stays in the HLT. Don't move it. The PID gets switched to manual mode to control the boil. BTW - you only need one SSR as the element switch is a double poll - double throw - center off switch.

THANK YOUUUUUUUUUUUUU. I'am in. EVER BODY TO :rockin:

Double-R feel free to shoot me a PM if you have questions. P-J walked me through a lot so if you have questions I probably have answers. Currently awaiting a free day to build my control panel. I decided recently that I want to mount my march pump in a toolbox with the panel.

If you looking to save costs, I recommend batch sparging so you only have 1 pump. There is also the option on 2 tiers, one pump, fly sparge.

Is there any reason you couldn't use two thermocouples and use a switch so I would be able to see temps in both the HLT and BK?

rcm_rx7 said:

Is there any reason you couldn't use two thermocouples and use a switch so I would be able to see temps in both the HLT and BK?

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You could do that - But - why bother with the boil kettle temp? Water simmer boils at 212°F & a very vigirous boil is also at 212°F.

P-J said:

You could do that - But - why bother with the boil kettle temp? Water simmer boils at 212°F & a very vigirous boil is also at 212°F.

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Yeah that's true. My reason for wanting it is only to see how close to boil I'm getting, and maybe to monitor temps during cooling and whirlpool. Might now be worth the hassle, and extra hole in the Kettle.

i used the connectors at auberins.com for the HLT/BK PID when I switch my power cord from vessel to vessel I switch the temp probe cord

rcm_rx7 said:

Yeah that's true. My reason for wanting it is only to see how close to boil I'm getting, and maybe to monitor temps during cooling and whirlpool. Might now be worth the hassle, and extra hole in the Kettle.

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If you are using RTDs, you could put a 3-pole, double throw switch (3PDT) in the box to select one probe or the other. RTDs are more tolerant to long wires and switches/connectors in their path than thermocouples are, so it would probably work.

But, remember.... each temp probe might (probably?) have a static error on it. I've used a couple of different probes and they all had different error values, from 0.5*F to 2.5*F. You can program the PID to account for the error, but if you are switching probes, then they could each have different error values.

But, if the BK probe is just to estimate how close to a boil you are and how close to pitching temps you are, then maybe the error on that probe can jus tbe left as an error and you can tune the PID for the other probe.