Planning Ahead For my Control Panel

[jrmorrill]

I am planning on making an upgrade within the year to a HERMS system and I have a rough outline of how I would like the controls to work. Below is a quick sketch of the different circuits.

The top circuit has an electrical heating element controlled by a thermostat for the HLT. The bottom circuit contains three different methods for controlling the pump.

1. This circuit will be used for circulating the wort when it drops below the target temp.
2. This circuit will be used in the sparging process to automatically turn the pump on/off as needed.
3. This circuit will be used for pumping wort/water from the kettle when needed.

I think that I might need some kinda relay system but I'm no electrician so I have no clue how to go about it. If anyone could give me some pointers or a place to look for advice it would be greatly appreciated!

 

[Walker]

what kind of temp controllers are you planning to use?

I am not sure how the float-switch will work out for you for controlling a pump. I think that is going to make the pump rapidly turn on and off, which may not be good. You're probably better off using a valve to control the flow rate from the pump and just match it to the MLT drain rate. The float could be used as a back-up safety measure to shut the pump off if the MLT starts to get too full, though.

Also.... i think you have some conflicting design points here. Most people turn on and off the heating element with a controller during circulation but just leave the pump running constantly. Meaning, I don't think you need 2 temp controllers at all for this. I am not sure how well two controllers would work, but it all depends on a lot of things.

Where are your temp probes going to be located?

 

[SweetSounds]

It should work - Controller 1 maintains HLT temp for the herms, and controller 2 fires the pump when mash temp drops.

It may not be necessary, though. Once you learn the thermal loss in your system you can plan for the temp drop, and dial in the HLT temperature difference. IOW you'll learn that for 152 degrees in the mash, you HLT/HERMS will have to be set for 156 or whatever it winds up being.

Once you're there, just leave the pump on and throttle it with a valve on the output.

heh - Walker beat me to it...

 

[Walker]

BTW: I realized that I made the assumption that you are fly sparging. Is this correct?

SweetSounds: I see what you are saying about the two controllers and cycling the pump. That's kind of why I was asking where the temp probes are going to be in this thing.

 

[Ohio-Ed]

I had the same thought as Walker about maybe an issue with turning on the pump based on temp... One problem is that the pump & plumbing is going to cool between cycles, and will cause the temp to drop even further when it initially comes back on.

I would be interested in the design requirement to cycle the pump vs run continuous?

As for a float switch... I considered using a grant during fly sparging. So basically, you drain the MT slowly into the grant and pump the grant into the BK when it gets full. This would prevent any "suction" on the MT and prevent stuck mash. However... I have been recirculating and pumping straight from the MT to the BK and have yet to have a stuck mash. I don't foresee the need for a grant in my system.

Ed

 

[Bret86944]

I am not sure how the float-switch will work out for you for controlling a pump. I think that is going to make the pump rapidly turn on and off, which may not be good.

Why would the pump turn on and off rapidly?

 

[Walker]

Everytime the level drops and triggers the switch, the pump comes on. It won't take very long at all for the pump to push enough liquid in to make the switch flip the other way, and then the pump turns off.

It'll constantly be turning on and off keeping the liquid level bouncing back and forth and flipping the float switch.

 

[jrmorrill]

what kind of temp controllers are you planning to use?

Possibly a Ranco or a Johnson Controlls ETC

Where are your temp probes going to be located?

The top temperature probe will be in the HLT to maintain a constant 180 degree temp. The other probe should be in the mash tun somewhere... Probably as far away from the return manifold as possible.

I realized that I made the assumption that you are fly sparging. Is this correct?

Yep that's right.

This would prevent any "suction" on the MT and prevent stuck mash.

What would cause a suction? For my system, the MLT will be located above the Kettle and during sparging the wort would be gravity fed to the kettle. I shouldn't hafta worry about suction if I'm not pumping from the MLT right?




I think I see what you guys mean when you are talking about the float switch problem. The pump would be turning on and off as the mash fills with water and then drops. I based my design off the Powers and Lama systems and I'm not sure what they do to control the flow...

http://powersbrewery.com/
http://www.lamabrewery.com/

I suppose I could connect the float switch to a solenoid valve that half-closes to reduce the flow. At any rate though I can work without the switch and simply adjust the ball valves as necessary to compensate for the flows until they are nearly equal.

 

[Walker]

What would cause a suction? For my system, the MLT will be located above the Kettle and during sparging the wort would be gravity fed to the kettle. I shouldn't hafta worry about suction if I'm not pumping from the MLT right?

But you WILL be pumping from the MLT. During the recirculating mash, you will be pumping the wort from the MLT, through your HERMS coil, and then back into the MLT.

 

[Ohio-Ed]

What would cause a suction? For my system, the MLT will be located above the Kettle and during sparging the wort would be gravity fed to the kettle. I shouldn't hafta worry about suction if I'm not pumping from the MLT right?

If you were doing a single tier, you would have to pump from the MT to the BK... But as I said, I do it and so do lots of others with no problem.

But you WILL be pumping from the MLT. During the recirculating mash, you will be pumping the wort from the MLT, through your HERMS coil, and then back into the MLT.

I don't know that the OP has gotten that far... I think he is just thinking about heating the HLT?? But, we know where this is going don't we

 

[Walker]

If you were doing a single tier, you would have to pump from the MT to the BK... But as I said, I do it and so do lots of others with no problem.

Right. I don't use a grant and (provided I don't run the pump wide open) don't have problems with the suction.

Oh, and if he was doing single tier with fly sparging, he'd need another pump, too.

I don't know that the OP has gotten that far... I think he is just thinking about heating the HLT?? But, we know where this is going don't we

Well... he did have "HERMS" in his very first sentence in the of this thread, and he's got one probe in the MLT to trigger wort pumping and one in the HLT to maintain a waterbath temp.

It seems pretty clear what the plan is from where I am sitting.

 

[jrmorrill]

But you WILL be pumping from the MLT. During the recirculating mash, you will be pumping the wort from the MLT, through your HERMS coil, and then back into the MLT.

Oops I totally forgot about that... Yea I will be pumping from the MLT and through the heat exchanger and then back to the MLT from the return manifold. Sorry, I'm still a newbie haha! I haven't even made an All-Grain brew yet. But I'm really excited to get started on one! Here is a link to my post about my Stage 1 plans for an economy system with out all these bells and whistles.

https://www.homebrewtalk.com/f36/im-ready-build-my-first-all-grain-system-any-advice-185675/

Once I get that built and pump out several good quality All-Grain brews I'm sure I will have a better idea about whats going on I already got a Belgian Triple recipe I want to try for my first All-Grain beer!