PJ diagram modification

[dkmag]

I'm building a control panel based on one of PJ's diagrams, but I want to add one of the new Auber DSPR1 for boiling control. I've modified this diagram and wanted to get some feedback to see if I've done wiring correctly.

The idea here is to be able to use the PID to control the elements in both the HLT and the BK. The HLT is has a HERMS coil and so the PID will be controlling the mash temps. For the BK I want to be able to use the PID to set the temp just below boil and then trigger the alarm when the temp is reached. Then switch over to the DSPR1 for boil control for the rest of the boil.

I will do the auto-tuning on the HLT. The BK will have the same element (5500w Camco ULWD) and is the same size/volume and the HLT so I think I should be able to use the PID with the same settings.

Anyway, here's the modified diagram.

Thanks,
Dan

 

[schematix]

I wouldn't tie the 2 SSR- signals together. It could be ok, but without knowing the internal circuit for each one I'd be leery doing that. And even then if they don't have precisely the same voltage level you'll be short circuiting through them.

You could use a DPDT switch and switch both signal paths though and you'd be ok in that aspect.

 

[Brumateur]

Diagram is OK. You can tie to SSR signals together since PID has galvanically insulated power supply. However DPDT switch as schematix suggested will be safer option.

 

[dkmag]

Great. Thanks for the feedback.

Can I use the same switch (Auber SW2) and just stack another pair of NO/NC blocks on the switch? These.

 

[doug293cz]

If you want to use the PID on both the HLT and BK, you need to have two temp probes and a way to switch which one is connected to the PID. Ideally, this switch would be mechanically ganged to the switch controlling the heater current contactor coils.

Brew on

 

[jeffmeh]

If you want to use the PID on both the HLT and BK, you need to have two temp probes and a way to switch which one is connected to the PID. Ideally, this switch would be mechanically ganged to the switch controlling the heater current contactor coils.

Brew on

I believe you really only need one temp probe, say in the HLT, then when switching the BK to power the boil, you would use manual mode and the temperature would not be relevant.

 

[doug293cz]

I believe you really only need one temp probe, say in the HLT, then when switching the BK to power the boil, you would use manual mode and the temperature would not be relevant.

OP said: "For the BK I want to be able to use the PID to set the temp just below boil and then trigger the alarm when the temp is reached."

Brew on

 

[BadNewsBrewery]

Definitely need to switch the temp probe if you want to run Auto in both, which it sounds like OP wants to do.
Option 1- Put a probe in both, just switch the wire between the two. Easy enough to do with most of the temp probes out there as they come with a quick connect at the probe. Downside - if you forget to switch one, the PID isn't going to get feedback and will overheat the wrong kettle.
Option 2- Wire both temp probes to the same switch and stack on THREE NO/NC blocks, one for each of the 3 temp probe wires. Then one switch will switch the SSR signaling wire and the PID temp probe. Downside - can you really stack 5 contact blocks that deep in your box?
Option 3- Wire both temp probes to a separate switch with 3 blocks. Switch it at the same time you flip all the other switches.

The issue - you already have 2 switches you need to manipulate to make sure things are going correctly - 1 to determine which of the two outlets is getting power, and 1 to determine if the PID or DSPR1 is controling the SSR. Option 3 would mean another switch to determine which temp probe is sending signals. What a headache...

I'm missing why you don't want to use the PID in manual mode like so many others have. You can run the PID in auto to near boil temps, and then switch it over to manual for the final push. Install one outlet and one temp probe wire. When you're ready to switch from mash/HLT to boil, unplug the HLT element and plug in the BK element, move the temp probe wire from the HLT to the BK, and you're in business. Harder to mess that up, fewer switches to confirm they're in the right position, and fewer duplicate components in your panel. Just my 2 cents - your panel is yours to build like you want.

-Kevin

 

[Brumateur]

Regular DPDT switch is able to control thermosensor selection.
If you add a DPDT relay with 120V coil connected in parallel with one of contactor coil it will automaticaly select proper thermoprobe .

 

[schematix]

Regular DPDT switch is able to control thermosensor selection .

Don't do this if you have a thermocouple as your sensing device. You will be introducing another junction and you'll get an offset to your temperature. I've seen this done before and it changes by more than a few degrees. Other sensor types are ok though.

 

[Brumateur]

Don't do this if you have a thermocouple as your sensing device. You will be introducing another junction and you'll get an offset to your temperature. I've seen this done before and it changes by more than a few degrees. Other sensor types are ok though.

PT100 is pretty much standard type of temperature sensors for brewing application. And PT100 is not thermocouple.

 

[BadNewsBrewery]

Most temp sensors I've seen used around here are 3 wire. How is a DPDT switch going to handle 3 unique wires?

 

[jeffmeh]

OP said: "For the BK I want to be able to use the PID to set the temp just below boil and then trigger the alarm when the temp is reached."

Brew on

Agreed, to run auto mode in both vessels.

 

[dkmag]

Option 1- Put a probe in both, just switch the wire between the two. Easy enough to do with most of the temp probes out there as they come with a quick connect at the probe.

Thanks for the input. This is what I was planning to do. I will have the probes mounted on the outputs of the HLT and the BK and then just do the switch manually.

I also use and IC and whirlpool for chilling and with the probe on the BK I can monitor temps while chilling.

I'm missing why you don't want to use the PID in manual mode like so many others have. You can run the PID in auto to near boil temps, and then switch it over to manual for the final push. Install one outlet and one temp probe wire. When you're ready to switch from mash/HLT to boil, unplug the HLT element and plug in the BK element, move the temp probe wire from the HLT to the BK, and you're in business. Harder to mess that up, fewer switches to confirm they're in the right position, and fewer duplicate components in your panel. Just my 2 cents - your panel is yours to build like you want.

I understand about using the PID in manual mode but I'm a bit old school and just prefer knobs and switches to digital button interfaces. Just a personal choice.

For boil I will manually switch probes, flip the element select switch to the BK, set the PID temp to 208. When the temp is reached flip the switch to the boil controller.

I can always change the boil controller out later if I find out it's a hassle and maybe drop in a timer.

Cheers,
Dan