BruControl: Brewery control & automation software

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Quick question for @BrunDog, @augiedoggy et al.: as I begin wiring the DC side of my control panel, is it ok to use a common ground for my various DC voltages? I have a 12v power supply, a step-up transformer to run a single 24v accessory, and a 5v power supply to power any 5v items that I deem excessive for the Mega. My schematic has all of the grounds tied together in a single terminal, and I have a power distribution board into which I currently plan to wire all of my DC grounds. I just want to check that this appropriate before I get too far into the wiring.

Thanks!

-Adam
 
Yes... you should always use a common DC ground. All grounds should ideally tie to one point (star ground format) to reduce ground loops (ground points that have a wide area of connections becomes a big antenna to collect noise). You should also tie your AC ground to this point to further reduce noise and increase protection, but this is optional.
 
Yes, I think these will work well. In reality you only need to tie the back plane once, so I personally don’t think a price premium would be worth it if you needed lots of ground terminals as you would be paying for that feature multiple times... if these are compatible with non-grounding terminals and you could mix and match that might save you a bit. You also need to ground the enclosure and door if they are metallic.

Make these terminal blocks the center of the “star”.
 
Seems I have "misplaced" some of the parts I ordered for this project last year. I must have put them someplace "safe". I have reordered the missing parts, some have arrived and the rest will be here by mid week so I will be able to build out the high voltage side. I still need to figure out what temp probes would be best. I am also debating the best way to get holes in my pot, carbide hole saw vs radio punches. I will be starting a thread for this build soon.
 
I would not recommend tying any DC ground to AC Safety Ground.
There's no logical reason to do that and at least one good reason not to...

Cheers!
 
shadow160 said:
Seems I have "misplaced" some of the parts I ordered for this project last year. I must have put them someplace "safe". I have reordered the missing parts, some have arrived and the rest will be here by mid week so I will be able to build out the high voltage side. I still need to figure out what temp probes would be best. I am also debating the best way to get holes in my pot, carbide hole saw vs radio punches. I will be starting a thread for this build soon.
Click to expand...

I'd use punches where possible, carbide for the big holes. Regarding temp probes... that's a personal call... If I were building from scratch and money wasn't super critical, I'd go RTD. If you are comfortable building sensors, thermistors can be a good option too. If ease of use is most important, 1-wire is OK, but anything more than a few sensors can slow things down a bit.
 
day_trippr said:
I would not recommend tying any DC ground to AC Safety Ground.
There's no logical reason to do that and at least one good reason not to...

Cheers!
Click to expand...

Curious why you state this? You can keep the ground buses separate, but you will often find better noise reduction and isolation when these are tied to each other. Remember that voltage differentials create avenues for significant EMI to infiltrate control systems. Tying these is certainly an optional decision, but I don't know a reason not to.
 
The RTD temp probes look like they are about 14 bucks, that is not going to break the bank. Do they need the filter boards also?
 
as far as the grounds go, I have mine tied together but all the devices powered by the arduino also get the ground directly from it. I this was the only way I could get stable spike free performance on my RTDs. (Maybe I was creating a ground loop otherwise since my arduinos power was already grounded to the other dc power supply.) basically only my relay boards, RTDs and my amp meter coils use the arduino ground which is tied to the main ground for my 12 and 24v power supply.
 
@day_trippr what is the reason not to? I work on power distribution systems for $40m yachts, and all DC negative, AC grounding, and cathodic bonding systems are tied together at one point in the vessel. Everything is maintained at the same potential. Furthermore, that is the requirement for the major classification ratings, including ABS, Lloyd's register, and ABYC.
 
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I'm just noticing some RTD spikes (well drops to -196C actually) on my system. I was able to solve my earlier problem with them by installing diodes on my contactors which prevented the spike when shutting down the contactor. However, now I am seeing spikes from all sorts of places. I installed an MOV on my glycol chiller which prevents the spike at shutdown but I am still getting a spike when it turns on. The MOV is in parallel with the load and attached as close to the load as possible. The other place is my grain mill which is powered not by the control panel but my a separate outlet on the same 240v circuit which powers the panel. I get a spike at both startup and shutdown. My solenoid and contactors have been working flawlessly since installing the diodes though I did increase the size of the diode on my contactor since the 1N4001 wasn't getting the job done the 1N4004 I had on hand has solved the issue. Any ideas on how to target these spike issues? I have checked all the grounds and the RTD board and other 5v devices are wired to the arduino grounds and the arduino is then grounded to the ground bus. I'm contemplating pulling the the ac ground that is tied to the DC ground and see what happens but it makes no sense how my mill on the other side of the shop is affecting the RTDs...
 
Is there a good thread somewhere that goes over make/model of various instruments popular with this platform?

I’m looking to source parts for an automated Brucontrol build that will use automatic ball valves, flow meters, flow control valves, etc. I would also want both HMI touch screen and remote control. Any help finding a good build list would be much appreciated. Thanks!
 
@BrunDog-- I have a couple of questions for you regarding your pressure-based volume measurement: what happens to the volume measurement in the mashtun when grain is added? Does the pressure increase by the weight of the grain or by the total displacement of water+grain? Or something in between? Do you account for this in BruControl or do you simply measure your strike water and wort into the boil kettle and call it a day?

Similarly, the wort collected in the boil kettle has a density a few percent higher than water--does your BK volume measure take into account your estimated/measured pre-boil gravity to determine the volume into the kettle or are those few percent just not really worth bothering with in your opinion?

Thanks!
-Adam
 
HobbyBrauer said:
I'm just noticing some RTD spikes (well drops to -196C actually) on my system. I was able to solve my earlier problem with them by installing diodes on my contactors which prevented the spike when shutting down the contactor. However, now I am seeing spikes from all sorts of places. I installed an MOV on my glycol chiller which prevents the spike at shutdown but I am still getting a spike when it turns on. The MOV is in parallel with the load and attached as close to the load as possible. The other place is my grain mill which is powered not by the control panel but my a separate outlet on the same 240v circuit which powers the panel. I get a spike at both startup and shutdown. My solenoid and contactors have been working flawlessly since installing the diodes though I did increase the size of the diode on my contactor since the 1N4001 wasn't getting the job done the 1N4004 I had on hand has solved the issue. Any ideas on how to target these spike issues? I have checked all the grounds and the RTD board and other 5v devices are wired to the arduino grounds and the arduino is then grounded to the ground bus. I'm contemplating pulling the the ac ground that is tied to the DC ground and see what happens but it makes no sense how my mill on the other side of the shop is affecting the RTDs...
Click to expand...

First step is to make sure all grounds come to a common point. Make sure low voltage cabling is as short as possible and your HV and LV components are as separate as possible. Along the same lines, avoid running HV and LV wires next to each other. You can twist any longer DC wires to eliminate loops (aka antenna's) to make them more immune to noise. Depending on how the RTD amps are powered, you might improve their noise resistance with capacitors on the voltage input. Shielding your RTD cables can help and make sure they are grounded can help.

Just because your motor is across the room doesn't mean much... electrical noise comes back through the wires when the motor starts and stops. The MOV and/or RC snubber used alone or in combination should help.

If you have a schematic and/or pictures you can share, that might help us give you better direction. There are lots of online resources on EMI reduction, but I have listed some of the basics.
 
Maltose said:
Is there a good thread somewhere that goes over make/model of various instruments popular with this platform?

I’m looking to source parts for an automated Brucontrol build that will use automatic ball valves, flow meters, flow control valves, etc. I would also want both HMI touch screen and remote control. Any help finding a good build list would be much appreciated. Thanks!
Click to expand...

Unfortunately, the only list I know of is what people have posted here or on the BruControl website. The website offers some items, but we generally suggest that common items be purchased elsewhere since that will reduce your cost. We should update the Order List we have to include more than the interface components, and maybe make that a community editable file.
 
adman said:
@BrunDog-- I have a couple of questions for you regarding your pressure-based volume measurement: what happens to the volume measurement in the mashtun when grain is added? Does the pressure increase by the weight of the grain or by the total displacement of water+grain? Or something in between? Do you account for this in BruControl or do you simply measure your strike water and wort into the boil kettle and call it a day?

Similarly, the wort collected in the boil kettle has a density a few percent higher than water--does your BK volume measure take into account your estimated/measured pre-boil gravity to determine the volume into the kettle or are those few percent just not really worth bothering with in your opinion?

Thanks!
-Adam
Click to expand...

Great question! On my personal system, I fill water to a strike volume (where exactness is important), then add the grain, then measure that volume and record it as the mash volume, which is only later used to detect a sticking mash and to set the level to be maintained during fly sparging. I don't really care what that volume is, so the short answer is "call it a day".

If you wanted to measure the actual volume, you would need so plain old fashioned math to determine the volume of the mixture. You would need to add the mass of the water to the mass of the grain, then device the sum of the volume of the water and the volume of the grain to get an accurate density, then use that in your calculation. Basically you are averaging densities, but as mentioned I haven't done this.

The wort in the kettle indeed has a higher density, but only by 4 or 5%, so its not a biggie. I think if you were to calibrate for this density, you could dial in some more accuracy and call it a day (again), because the wort going over isn't going to vary much from that (say -0.02 to +0.03 if your pre-boil wort was 1.030 to 1.080 and your calibration was at 1.050), and 3% or so really doesn't matter much IMO.
 
All of which (some of which I account for) in the calibration settings. But you will have to base your calibration off either assumption ( recipes) or get a mass flow and use that input.

I found it easier to measure flow over volume because of this. Plus on my setup I pressurize the vessels which messes with sensors anyways. That being said I I still have the sensors.
 
@BrunDog & @GParkins, my perspective starts back in the 70s and 80s when I designed memory systems for IBM mainframe computers and extends through super-mini system design at DEC to fault-tolerant platform design at Stratus to solid state storage design today. In all of those environments one thing is shared: never tie DC/logic ground to chassis ground (and by extension to AC Safety ground). The reasons have always been threefold: ground loop avoidance, EMI (emissions) reduction and EMC (resistance to EMI) enhancement. Even today all of the chassis holding modules and power supplies and shields around connectors are isolated from logic/DC ground, in some cases via fancy filters, others simple electromechanics.

I can imagine systems riding the waves have a different, more compelling reason to do what they do (galvanic corrosion is no small deal, even on my own wee boat) and don't have to pass the same type of EMI testing we did/do (test chamber size would be an issue I'm sure ;)) but I can say in my space it just doesn't happen.

I mean, we actually have to float the AC ground lugs on our 'scopes and data acquisition systems because those DO tie their probe ground inputs to their chassis (and by extension, AC Safety ground) and we can't have the scope become the path to tie logic ground to AC ground. Bad juju...

Cheers!
 
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Ozarks_Mountain_Brew said:
most people don't realize this but ac runs to it's point executes then cancels itself out with ground, at least that's the plan, most are wired wrong at some point but DC runs in all directions and reacts from all directions and needs a path and point to run too and that's what a diode does
Click to expand...

With all due respect... I have no idea what you are saying here!
 
Ozarks_Mountain_Brew said:
this feedback issue some people are have can be solved with a simple diode, the signal only goes one direction
Click to expand...

Sorry, that is not accurate... EMI noise is always an AC signal. It's not a pretty sinewave type of AC, but rapidly alternating, erratic electrical potentials with no time base or regularity. The noise needs to be damped or clamped or both. I'm not sure in what manner you are proposing to use a diode, but I don't think just adding one haphazardly will solve any ills. Diodes also have breakdown voltages upon which they will conduct in reverse direction (and with probable damage). EMI can be thousands of volts.
 
@BrunDog Yes all grounds are tied together and this bus is tied to protective (AC) ground. All the EMI I am seeing is when high-draw inductive devices turn on or off. To me there are two separate things that need addressing. The first is the EMI generated by ac elements connected to the panel. These I have a good plan of attack thanks to your suggestions! The second, is EMI from devices on the same circuit but outside the panel. Is there a way to prevent this EMI from entering the panel? The 240v circuit I am using is also used for other high power devices (shop tools, car charger, compressor etc.) which I would prefer not to modify.
 
HobbyBrauer said:
@BrunDog Yes all grounds are tied together and this bus is tied to protective (AC) ground. All the EMI I am seeing is when high-draw inductive devices turn on or off. To me there are two separate things that need addressing. The first is the EMI generated by ac elements connected to the panel. These I have a good plan of attack thanks to your suggestions! The second, is EMI from devices on the same circuit but outside the panel. Is there a way to prevent this EMI from entering the panel? The 240v circuit I am using is also used for other high power devices (shop tools, car charger, compressor etc.) which I would prefer not to modify.
Click to expand...

Something seems odd that your panel is that sensitive. I think the best to try is some noise isolation MOV's and RC snubbers on the entrance to your panel, but I am not sure I can tell you how to size them. You might look for some off the shelf isolators.

That said, I would like to better understand your panel config. Can you send me a schematic, or pics of the panel?
 
Hi All,

Just wanted to give you a heads-up that we will be posting a beta version 44 of the firmware in the next few days. It will incorporate a few minor bug fixes and internal optimizations (memory management, start-up speed, debug reporting). It will also offer the ability for the user to store a default device configuration such that on power-up it will initiate those devices. For example, if you had a fermentation controller without (battery backup or BruControl connected), and a power failure occurred, the interface would load the default devices (such as a temp probe and hysteresis device driven off that) on start-up and run in that mode until BC connected and made any changes. This will give those interested in running simple controls offline the ability to do it and provide some additional security when several links in a chain are broken (Murphy's law happens). The device configuration gets stored in the EEPROM or flash, so no additional hardware is needed, but this means it is meant for only occasional times this data is written, as these memories have a limited use lifetime (maybe 100k for EEPROM in the MEGA and 10k for flash in the M0, ESP8266, ESP32, M4, Due).

This FW will be beta so we suggest it not be used in production just yet. It will also support ESP32, but going forward we will drop support for the Uno (sorry, memory constraints), 101 (memory, unpopular, appears headed for the graveyard), and Primo (sigh). We almost have the M4 based chipset adopted...

In other news, I know we have promised BC v1.1 for some time, but I think there is light at the end of the tunnel... I don't want to make any more undelivered promises, but stay tuned. Finally, we are working on a universal shield based on the Feather format - it will provide high current outputs for direct wiring to pumps, valves, etc. without needing relay boards. Thanks for your patience!
 
sorry guys I was combining 2 thoughts while working and not being very precise just disregard :),
the ground issue can be a problem though, when building copy machines, we had a problem with tying both together and decided to use an isolated ground and a regulator for power coming in and that solved the issues but also think of cars and boats, they have no ground to earth and work off the chassis just fine but either way it can work if your ground is true ground to earth, everyone's house wiring may be different
 
Since the beginning, we have noted that tying these two together was optional. I don’t see any reason that doing so is dangerous. At the end of the day we are ensuring that a reference is made. If AC noise centers around a neutral, and the DC ground is isolated from it, it can create an avenue for the noise entering the DC system to be at a higher potential.

So I think it’s rational to keep them isolated, then tie them if noise is an issue to see if this resolves the problem. In my personal system, I have no noise and no snubbers or MOVs and they are tied, and I have no noise. I know an N of 1 isn’t anything scientific or definitive... just my experience.
 
BrunDog said:
Something seems odd that your panel is that sensitive. I think the best to try is some noise isolation MOV's and RC snubbers on the entrance to your panel, but I am not sure I can tell you how to size them. You might look for some off the shelf isolators.

That said, I would like to better understand your panel config. Can you send me a schematic, or pics of the panel?
Click to expand...

I agree something is definitely off here. I will snap some photos and upload when I get home tonight. I did pop in a second MOV across the relay contacts for the inductive load (glycol chiller) and this did nothing to reduce them. I'm going to try floating the DC ground tonight as well and see if that will reduce this noise. Looking at the block diagram for the 24v Mean Well PSU I am using it shows that both DC outputs are already tied to ground via a unspecified capacitor. I wonder if me grounding my dc ground bus to the ground created some form of loop which is inducing the noise I'm seeing. At this point I'm not even sure where the noise is coming from as I am seeing it on 120v inductive loads and 240v so its either on one of the hots or the ground. Will get back to you tonight with more data and photos!
 

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