120v Dual Element (one at a time) PID Controller Questions (and then hopefully build)

Attn: P-J, maybe you have done this before but I can not find it so…

My current setup is a double keggle system, one for the hot liquor tank and one for the boil kettle, with a 10 gallon water cooler mash tun and a March pump. I have a single 2000w heating element in each keg, which has served me well so far but I would like finer control and to stop physically plugging elements in. My problem lies in that I currently have access to a single 20A circuit to brew off of. So this controller will need to control both elements, but only one at a time (i.e. the HLT OR the BK, no need to have both running). Further I don't really need the PID to control the BK, at least not automatically the temp probe will live in the HLT (it all ready has a thermowell). I really like the design of the following post.

I would like something very similar but with the option of choosing which element is on and an indicator light to remind me which one is. I was thinking a switch that chooses between the two as opposed to on/off switches for each, that way both elements can not be on simultaneously thus preventing an overload. I am guessing pre contactor or SSR?

Thanks in advance for any help, I really appreciate it.

Edit: I just thought of another possible option, instead of a 2 way switch (HLT or BK) maybe a 3 way switch (HLT, off, BK) that would remove the need for a separate element switch.

https://www.homebrewtalk.com/f170/110v-recirculating-ebiab-2-5-gallon-batches-341219/

Twitched,

I Hear you and want to help you but at the moment I am having a serious problem with my computer that I hope to get resolved in a few days. I cannot boot my system normally and have to come up and running in safe mode. I lost 2 critical program files in my op system. This seriously limits my ability to do drawings at this time. I figure (hope) to be back up on Tuesday or Wednesday. (Please.!)

Sorry.

P-J

No problem at all! Take your time, your help is very much appreciated. good luck with the computer! Thank you

P-J,
After much digging I finally found one of your diagrams that is almost exactly what I need except it is in 220V, and has an extra pump. I am fairly confident I can wire this up as a 120V instead, I have a couple quick questions.
1) What type of contractors would I use the 30A 120V or the 40A 240V?
2) Does the 3-way selector switch between the HLT and Boil kettle function as a main power on/off as well? I don't think so but I am not sure. If not I will still need a diagram to wire in a main power switch.
Thanks again

You just want the 30a with 120v coil contactor. The 3-way switch would have an off for the elements, yes; neither contactor would be opened. That's not a main-power though to your whole panel..

How you do that is have your neutral and hot from the power-in running through another one of those contactors first thing. Then from there to your power distributors/blocks. Here's pictures from my old 240v rig, but it's the same premise. Look on the left.

Thanks, iijakii that's what I was thinking.

I went ahead and ordered the parts from Auberins today based on the 2nd diagram, except in 120V. The only differences are that I went with the 120V 30A contractors, selector switches instead of push buttons with separate LED indicator lights, and a keyed selector switch for a main power switch.

Here is the total list from Auberins:

• 1 ea. Panel mount connector for RTD sensor
  Item #: RTDCON
• 1 ea. Platinum RTD. PT100 (6 ft. cable)
  Item #: PT100S
• 1 ea. 1/16 DIN PID Temperature Controller (SSR control output)
  Item #: SYL-2352
• 3 ea. Contactor, 2 pole, 30A, 120V Coil
  Item #: CN-PBC302-120V
• 1 ea. External Mount Heat Sink for 40A SSR (Rectangular)
  Item #: HS40ETL
• 1 ea. 40A SSR
  Item #: MGR-1D4840
• 1 ea. Flashing Buzzer, 110 or 240V AC. 22 mm
  Item #: FLBuz Power Voltage Option - 120V AC/DC
• 2 ea. LED Indicator, 22 mm, 120/240V
  Item #: IND-1
• 3 ea. LED Indicator, 22 mm, 120/240V
  Item #: IND-1
• 3 ea. Selector Switch, 2-Position Maintained 1NO 1NC, 22mm
  Item #: SW2
• 1 ea. Selector Switch, 3-Position Maintained 2 NO, 22mm
  Item #: SW3
• 1 ea. Key Selector Switch, 2-Position Maintained 1NO 1NC, 22mm
  Item #: SW8
• 1 ea. Emergency Stop (E-Stop) Switch, 22mm
  Item #: SW6

I got all the parts in today. I'm gonna start cutting the panel tonight, and hopefully get it painted tomorrow.

So life got in the way, but everything is painted and attached now. All that is left is to install the wiring and labeling.


All cut and partly sanded


Primed


After the second coat


Cured and all components installed, except the heatsink

Did you install a bunch of stuff on the back of the face? Odd.

Yes. The screws are for the contractors, and terminal strip.

The housing is an old cash register drawer. The front is what used to be the top. It already had a bunch of holes drilled in it. And the back (old bottom) is much thinner metal. So that's the way it worked out. It's actually kind of nice because the back has no components or wiring. Makes it very stable, no moving wires.

Here is a look at the inside

Makes sense. Certainly made wiring easier I reckon!

So I'm about halfway done with the wiring. But I've come across a question I can't find an answer too. I'm working on E-stop (based on the 1st pj design above) and am now wondering what gauge wire to run for the hot line. I'm guessing that 14 gauge thhn should be enough, since it's running thru those in-line resistors. Is this correct?

Twitched said:

So I'm about halfway done with the wiring. But I've come across a question I can't find an answer too. I'm working on E-stop (based on the 1st pj design above) and am now wondering what gauge wire to run for the hot line. I'm guessing that 14 gauge thhn should be enough, since it's running thru those in-line resistors. Is this correct?

Click to expand...

The wire size for that circuit can be much smaller that that as the trip current is less than an amp of current,

Just sayng.

P-J

Awesome, that is what I was thinking. Thanks so much! Hopefully I'll have it up an running in a day or two.

Subbed


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Alright, I got the wiring complete and everything sealed up. All that's left is to replace the regular house outlet with a gfci 20A outlet. And then a test run.



Wiring all done!



In place



With the whole rig