Semi-automated Electric Biab

[aaronpetersen]

I know that many of you don't agree with the idea of automated brewing, but it's an avenue that I have decided to head down. The first step I want to take on my way to what will hopefully one day be full automation, is to be able to do automated step-mashes. I'm a BIABer and I think this system lends itself well to automation (as proven by Zizzle) so I have decided to stick with BIAB for this system. I'm reasonably handy at mechanical type things (welding, drilling, tying shoelaces) but I know next to nothing about electrical gadgetry and associated witchcraft. So, can all you electronics whizzes please give me some advice.
My basic idea is to insert two 2200W elements (Craftbrewer ones) into my 50L aluminium pot with a false bottom covering the elements to keep the bag off them. I want two because I think one will be too slow at ramping temps for full batches. Also, because I often make half batches, I can just use one element when I want to. The elements will be controlled by a PID + SSR with a PT100 style temp probe to measure wort temp. The wort will be recirculated from the bottom to the top of the pot with a March pump to ensure even heat distribution. That all sounds simple enough, even to me, however there is one limitation that I need to mention that makes things more complicated.
I only have access to 10 amp circuits (one in shed and one from house via extension lead). That's enough juice to run the elements, but how do I wire the PID? Can I somehow connect both 10 amp circuits to one PID and have it split the current to each element (seems unlikely to me). Alternatively, do I connect each element to a separate PID, which is then connected to it's own power circuit. That seems like a feasible option but do I then need a separate temp probe for each PID or can they both share one probe via some tricky wiring and spell-casting? My final question is regarding the March pump. Can the March pump be operated by the PID/s so that it turns on whenever the elements are on?
Before LethalCorpse admonishes me for playing with electricity when i clearly have no idea what I'm doing, I promise to have everything I do checked by an electronics guru colleague at work before plugging anything in.
I shall now sit back and await the constructive comments and helpful advice.
Thanks in advance.

 

[beerbrewer76543]

I headed down this path before going 3V

One element controlled by the PID for mash control

The other simply plug into another circuit of your house via an extension chord for the boil

The temp probe could go in the recirculation line

 

[Malted]

Have you seen the German guy who made his own Braumeister? Let Google translate help you decipher it.
http://hobbybrauer.de/modules.php?name=eBo...p;orderdate=ASC

You've probably already seen this too? http://www.aussiehomebrewer.com/forum/inde...=55845&st=0

 

[Zizzle]

I haven't used one of the off-the-shelf PID controllers, but I think you should be able to use one for the job.

You will however need 2 Solid State Relays - one to switch the power to each of the heating elements. The output of the PID controller going to the input of both of the SSRs. i.e. the PID switches both relays on. Each relay is connected to a 10amp element circuit.

It looks like the PID controllers often have a 12V output.

You could also use a simple diode-resistorcapacitor circuit on the output of the PID to control your march pump. But I'm not sure that's really what you want.

It might be worth taking the plunge and learning to use something that can sequence the whole process. The arduino comes time mind as having a large enough community of beginner hackers to have a support base and tutorials to make it accessible.

On the other hand it's good to make a start and get something working, some part of the process automated.

I can do a circuit diagram for the above if needed.

 

[aaronpetersen]

I haven't used one of the off-the-shelf PID controllers, but I think you should be able to use one for the job.

You will however need 2 Solid State Relays - one to switch the power to each of the heating elements. The output of the PID controller going to the input of both of the SSRs. i.e. the PID switches both relays on. Each relay is connected to a 10amp element circuit.

It looks like the PID controllers often have a 12V output.

You could also use a simple diode-resistorcapacitor circuit on the output of the PID to control your march pump. But I'm not sure that's really what you want.

It might be worth taking the plunge and learning to use something that can sequence the whole process. The arduino comes time mind as having a large enough community of beginner hackers to have a support base and tutorials to make it accessible.

On the other hand it's good to make a start and get something working, some part of the process automated.

I can do a circuit diagram for the above if needed.

Thanks Zizzle. Your post has given me a slightly better understanding of how these things work. So the power to the elements goes through the relays only, not the PID? Reading between the lines on what you wrote, I assume the PID + relays can't be used to control the pump? As an easy solution, is there any problem with having the pump running continuously during the mash? I think that's how the Braumeister works.
I think I will have to go down the Arduino (or similar) path eventually, but as a first step I want to keep things fairly simple. With the setup you mentioned above, will that give me the flexibility to use only one element for when I do small batches? It would also be useful to have only one element going during the boil too,as I think both will cause boilovers.
A circuit diagram would be great!

 

[seamad]

I'm in the process of converting my urn. Have already got pid, ssr with heat sink, march pump etc.
Have attached some info that came with my pid which may be helpful.
Mine is a bit easier as only the one element.

cheers
sean


View attachment auber_pid1.pdf
View attachment auber_pid2.pdf

 

[aaronpetersen]

I'm in the process of converting my urn. Have already got pid, ssr with heat sink, march pump etc.
Have attached some info that came with my pid which may be helpful.
Mine is a bit easier as only the one element.

cheers
sean


View attachment 46944
View attachment 46945

Thanks Sean,
Those instructions have helped a lot.
Are you going to control the pump via the PID controller? If so, how? Do you just add an additional SSR to the SSR control output and use the PID in on/off mode or can you control the pump through one of the J1 or J2 control outputs?
Anyone know how many amps a march pump draws?

 

[seamad]

They only draw .007kW (licensed to kill)

I'm just going to run mine off a seperate switch. Will turn off at mash out. I think they handle up to 85C, not 100 % on that though.

 

[seamad]

Stand corrected. can go to 121C.

 

[Filby]

No problems triggering two SSR's with one PID controller.

 

[leonjw]

Hi Aaron

I'm pretty much doing the same thing but not sure about the step mashes yet. I'm going to have 1 element on one 10A circuit and the pump and PID on the other while I'm mashing/heating strike water. Then when boiling the PID and pump are turned off and that circuit is switched over to the second element to get up to boil nice and quick. Just one SSR. I've drawn up a wiring diagram let me know if you would like me to upload

Cheers
Leon

 

[aaronpetersen]

Hi Aaron

I'm pretty much doing the same thing but not sure about the step mashes yet. I'm going to have 1 element on one 10A circuit and the pump and PID on the other while I'm mashing/heating strike water. Then when boiling the PID and pump are turned off and that circuit is switched over to the second element to get up to boil nice and quick. Just one SSR. I've drawn up a wiring diagram let me know if you would like me to upload

Cheers
Leon

Thanks Leon. I'm keen to see how you have the pump wired to the PID so would love to see the wiring diagram.

 

[Bizier]

I don't understand why you would want two elements*. I would just have one element rated to boil the full volume, turn it down for mash temps, and let it rip for the boil. Also, I think it is silly to run the pump via the PID, just have it on a separate circuit with a switch. You want the element pulsing, but not the pump, it should just be recirculating steadily.

ED: *unless you require 2 elements to boil entire volume, but will probably exceed 10A

 

[leonjw]

oh sorry nah the pump is not wired to the PID but it is on the same circuit. I've got the pump switch wired so that the pump has to be on for the mash element to work (so I don't burn anything), so the pump stays on the whole time until the rig is switched into boil mode. I've got 2 elements so I don't overload the house circuits I.e one on each 10A circuit. If the diagram is a bit confusing my bad.

 

[aaronpetersen]

I don't understand why you would want two elements*. I would just have one element rated to boil the full volume, turn it down for mash temps, and let it rip for the boil. Also, I think it is silly to run the pump via the PID, just have it on a separate circuit with a switch. You want the element pulsing, but not the pump, it should just be recirculating steadily.

ED: *unless you require 2 elements to boil entire volume, but will probably exceed 10A

One of the first things I'm going to do is install one element in my pot and see how long it will take to ramp the temps between steps. That will then inform me as to whether or not I need an additional element. Before I started this thread I didn't realise that it is quite simple to add an extra element via the PID if I need it.
Although, if I only have one element, how do I control the boil vigour for different size batches? The element may be fine for a 30L start of boil volume but it's going to be overkill for a 12 L boil. I think it can be done by altering the duty cycle on the PID, but that would have to be done manually by trial and error, which means it is no longer automated. Basically what I'm asking is, is there a way to automatically control boil vigour?
I am beginning to think you are right about running the pump via the PID and will probably just leave it on during the whole mash, however I would still like to explore other options.

 

[aaronpetersen]

oh sorry nah the pump is not wired to the PID but it is on the same circuit. I've got the pump switch wired so that the pump has to be on for the mash element to work (so I don't burn anything), so the pump stays on the whole time until the rig is switched into boil mode. I've got 2 elements so I don't overload the house circuits I.e one on each 10A circuit. If the diagram is a bit confusing my bad.

Thanks Leon. The diagram does confuse me a bit, but that's more to do with my lack of familiarity with wiring diagrams than any fault of yours. I like the idea of not allowing the element to work unless the pump is on. Is that a March pump in your diagram? Are they only 12V?

 

[leonjw]

I've got a cheapy food grade pump from ebay (40 bucks) its actually 24V so I'll need a small power supply for it but it's rated up to 120c so hopefully it will have enough guts to circulate the wort around at a decent speed. March pumps are generally 240V which makes them simple to wire into the brewery controls. I have seen 12V versions of the 809 pumps on ebay though.

You could probably control the boil vigour by temperature if you had a probe mounted in the pot and just set the PID to the temperature of a rolling boil.

 

[Thirsty Boy]

With 2 x 10A circuits you will be fine to run both 2.2kW elements and your pump too. I run a 2400W element (theoretically 10A) and my March pump simultaneously off one standard 10A household outlet. It does push it to its limits... but there is a little leeway in those household outlets and the bit of extra power running through them needed by the pump isn't an instant trip-out or house fire. Just keep an eye on things. Besides, you are running 2.2kW elements, so you have 200W spare compared to me on either circuit... so if I can do it, you should be able to do it easily.

I think you can make your life a little easier though - you might need/want both elements running to give you speed in raising water to strike temperature, or raising wort from mash to boil - but for your temperature control and mash temp ramping purposes, ie: the stuff that will need to be driven by the PID and SSRs... I think you only need to have one element online.

In fact, I think that there is probably almost no point at all having 4400W worth of power running to your control circuit, its very unlikely that you will be able to re-circulate at a flow rate high enough to distribute that much heat anyway... so all that will happen is the exit wort will heat to target temp and all that power will get turned off (assuming you are measuring wort temp not mash temp... which is what you should be doing). To go back to my system as an example... I am running a 2400W element in my RIMS and bigger would serve no purpose... the mash temp lags behind the wort temp, because the re-circulation system cant distribute the heat as quickly as the element can supply it. Your ramp rate limitation in a re-circulating system isn't element power, its how fast you can re-circulate before you compact your grain bed, stick the mash and choke off the flow rate completely. I have heard of systems that allow you to run a march at full throttle, and everything being perfect, mine comes close to that - but even then... ramp time is limited by flow not element power.

In your system with a BIAB bag I suspect (don't know for sure but my book learnin' makes me think...) that your flow rate will be even more a limiting factor - the mesh of a BIAB bag is far from the ideal ratio of close space to open space for run-off and flow dynamics in a lautering system and my gut feel is that it will be even more prone to sticking. Remember, during the re-circulation phase - its not acting as a stuck mash proof BIAB bag, its just an extra layer on the false bottom of a normal mash tun, a less than ideal one.... so there is a goodly chance that your flow rates might be even trickier to manage than they would be in a more traditional tun.

All of which adds up to this - if it were me building this system (well, I would do it completely differently but...) I would put in the two elements, but - Have one of them just as a straight install, element in, directly to plug, it gets power and its on, nothing fancy about it - done. Have the other element wired via the SSR and PID, but no need for splitting etc, you can just do it the way everyone else does it without anything extra to complicate matters. Pump can run off whichever circuit you like via something no more complex than a double adapter.

When you are designing this system... think about flow rate as much or more than elements and power. Flow rate is the thing that will mess with your temp controller's ability to remain accurate and stable, flow rate is what will primarily influence your ramp rates during the mash, flow rate is what will stick it, ruin your mash and burn the snot out of your mash. The faster you can get it the better thing will work. Think about the fact that flow rates depend on false bottom surface area, grain bed permeability and to a lesser extent false bottom design. Consider the fact that a grain crush that gives a fantastic, fast, efficient BIAB mash - will be a nightmare of stuck mash hell the second you try get it to behave in a re-circulating system. You are abandoning the BIAB paradigm for a goodly chunk of your process, so you will have to start thinking like a mash tun brewer for those bits... grain crush, rice hulls, grain bed depth etc etc - all exacerbated by the re-circulating thing. Its not all that hard, its just different and you need to take it into account. Oh and ideally, your pump runs continuously and doesn't turn on and off at all.

Hope that gives you a bit of extra ammo in your decision making process. Cheers

TB

PS - the right sort of PID will allow you to throttle your element like a dimmer switch and thus allow you to control boil vigor ... most of the cheap ones don't work that way and you can't control boil vigor with them at all. You can't control boil vigor by temperature... its all isothermal in a boil. So be careful in your PID selection if that's what you want to do.

 

[aaronpetersen]

With 2 x 10A circuits you will be fine to run both 2.2kW elements and your pump too. I run a 2400W element (theoretically 10A) and my March pump simultaneously off one standard 10A household outlet. It does push it to its limits... but there is a little leeway in those household outlets and the bit of extra power running through them needed by the pump isn't an instant trip-out or house fire. Just keep an eye on things. Besides, you are running 2.2kW elements, so you have 200W spare compared to me on either circuit... so if I can do it, you should be able to do it easily.

I think you can make your life a little easier though - you might need/want both elements running to give you speed in raising water to strike temperature, or raising wort from mash to boil - but for your temperature control and mash temp ramping purposes, ie: the stuff that will need to be driven by the PID and SSRs... I think you only need to have one element online.

In fact, I think that there is probably almost no point at all having 4400W worth of power running to your control circuit, its very unlikely that you will be able to re-circulate at a flow rate high enough to distribute that much heat anyway... so all that will happen is the exit wort will heat to target temp and all that power will get turned off (assuming you are measuring wort temp not mash temp... which is what you should be doing). To go back to my system as an example... I am running a 2400W element in my RIMS and bigger would serve no purpose... the mash temp lags behind the wort temp, because the re-circulation system cant distribute the heat as quickly as the element can supply it. Your ramp rate limitation in a re-circulating system isn't element power, its how fast you can re-circulate before you compact your grain bed, stick the mash and choke off the flow rate completely. I have heard of systems that allow you to run a march at full throttle, and everything being perfect, mine comes close to that - but even then... ramp time is limited by flow not element power.

In your system with a BIAB bag I suspect (don't know for sure but my book learnin' makes me think...) that your flow rate will be even more a limiting factor - the mesh of a BIAB bag is far from the ideal ratio of close space to open space for run-off and flow dynamics in a lautering system and my gut feel is that it will be even more prone to sticking. Remember, during the re-circulation phase - its not acting as a stuck mash proof BIAB bag, its just an extra layer on the false bottom of a normal mash tun, a less than ideal one.... so there is a goodly chance that your flow rates might be even trickier to manage than they would be in a more traditional tun.

All of which adds up to this - if it were me building this system (well, I would do it completely differently but...) I would put in the two elements, but - Have one of them just as a straight install, element in, directly to plug, it gets power and its on, nothing fancy about it - done. Have the other element wired via the SSR and PID, but no need for splitting etc, you can just do it the way everyone else does it without anything extra to complicate matters. Pump can run off whichever circuit you like via something no more complex than a double adapter.

When you are designing this system... think about flow rate as much or more than elements and power. Flow rate is the thing that will mess with your temp controller's ability to remain accurate and stable, flow rate is what will primarily influence your ramp rates during the mash, flow rate is what will stick it, ruin your mash and burn the snot out of your mash. The faster you can get it the better thing will work. Think about the fact that flow rates depend on false bottom surface area, grain bed permeability and to a lesser extent false bottom design. Consider the fact that a grain crush that gives a fantastic, fast, efficient BIAB mash - will be a nightmare of stuck mash hell the second you try get it to behave in a re-circulating system. You are abandoning the BIAB paradigm for a goodly chunk of your process, so you will have to start thinking like a mash tun brewer for those bits... grain crush, rice hulls, grain bed depth etc etc - all exacerbated by the re-circulating thing. Its not all that hard, its just different and you need to take it into account. Oh and ideally, your pump runs continuously and doesn't turn on and off at all.

Hope that gives you a bit of extra ammo in your decision making process. Cheers

TB

PS - the right sort of PID will allow you to throttle your element like a dimmer switch and thus allow you to control boil vigor ... most of the cheap ones don't work that way and you can't control boil vigor with them at all. You can't control boil vigor by temperature... its all isothermal in a boil. So be careful in your PID selection if that's what you want to do.

Thanks TB, a lot of food for thought there. As a born and bred BIABer I never considered that recirc rates would be a problem. If I have the recirculating wort re-entering the vessel through the lid but piped down to just above the level of the false bottom (i.e. into the grain bed), will that disturb the grain bed enough to prevent it compacting and thus help maintain a high recirc rate? Alternatively, will pumping the wort up through the bottom of the vessel help, like in a Braumeister, or will the bag just get in the way?
I was planning on getting one of these PID controllers from Auberins. Will that be suitable for controlling the boil?

 

[Thirsty Boy]

I'm not saying that you wont be able to get a perfectly acceptable re-circulation rate, just that it will most likely be, as it is in most re-circulating systems, the limiting factor for temp control, ramp rates and the like. I was painting that as an opportunity for you to simplify your wiring needs - not as a problem. Your second element is basically irrelevant for your temp control system - you are safe to ignore it and make your life easier.

I can see that its possible that a system with a bag as well as a false bottom might perhaps be more prone to issues with the mash not circulating easily because the bag isn't the ideal lautering surface - but thats just something to be on the lookout for, its not that it "will" be a problem, just that its a possibility.

You could use the returned wort to "stir" the mash, and if i were building a BIAB re-circulating system, a way to do that would be part of my design... But i am NOT saying that i think its necessary for you to build a successful re-circing BIAB.

As a born and bred BIABer - you need to remember that the bag is NOT part of the mashing process, in normal BIAB, the bag is, or at least should be, entirely irrelevant to the mashing part of brewing, it should only come into play during lautering (ie when you pull the bag out). What you are doing with your re-circulation, is ALL about the mashing process, and basically nothing to do with BIAB. Read the threads about HERMS and RIMS brewing - they will be much more use to you than the BIAB threads. You suddenly need to understand mash tuns, you are about to build one. For re-circulation, flow rate matters, a lot. Think about it in your system design.

That auberins PID - sorry, i dont know. It says it has a "manual control" mode... But whether that means what we are talking about or not I dont know. You will have to discuss it with the seller/manufacturer, or perhaps someone from AHB who has one can let you know. I just wanted you to be aware that not all PIDs are able to control that way and make sure your's could if you needed it too.

Regardless of that, i would be inclined to run with two elements rather than one big one. This (probably) gives you a lower watts per square cm ratio - and thats a good thing for use in brewing. Also the elements from craftbrewer are nice smooth, easy to clean, stainless units - you will be able to clean them off with a quick wipe with a rag, no twists, bends etc to worry about. While the bigger units are normally water heater elements and are generally a bit more convoluted.

Me personally - I wouldn't build a system with these sorts of elements at all - I would do this

http://www.aussiehomebrewer.com/forum/inde...mp;#entry741566

Or some variation thereabouts, with a bog standard 2400W over the side element to add a little grunt to the situation when heating your strike water or trying to get to the boil. You only have a 50L pot, so i am assuming you are planning on single BIAB batches. Those crown elements are proven to hold a sufficient boil for single batches, so no need for control of the element during the boil, no extra installation or wiring for a "second" element & those elements seem almost perfect for installation under a false bottom. You also, by building a system like that, happen to be building a perfectly serviceable RIMS mash/lauter tun. So if you ever decide to to go 3V - all you do is take the bag out and add a kettle and HLT... No mods required for the mashtun/RIMS whatsoever.

There are bunch of different things that can and will work - just dont get too stuck in the BIAB paradigm for this build, its only partially applicable. Look at what you want, why you want it - and at what other people have done in similar situations. You really aren't doing anything new here, no need to re-invent the wheel.

TB