Crazy boiling after reaching setpoint

[foy1der]

I've just recently made the switch to both all grain and electric brewing. My first all grain batch was done in my new electric keggle. I made my own control panel as cheaply as possible. My brother had a love 16A temperature controller laying around so I built everything around that. I added a 5500w element and an SSR.

The long story short is that I can hit mash temps dead on. The system will stay at 165 all day long. BUT, when I need to bring the sweet wort up to a boil, everything goes crazy. I have never experienced a boil this vigorous. After Bringing the wort to a boil, I saw a boil over starting, I started stirring madly and spraying the head with water. But the only thing that abated the boil over was my wife adding about a half a gallon of cold water.

My brother, who sells automation systems, helped me build it, and told me turn down the gain, that the element was holding heat too much and couldn't dump the heat into the wort fast enough.

I initially bought into this but, if I unplug the kettle from the control panel, the boil stops almost immediately. I have tried turning the gain down, but that hasn't helped the incredi-boil.

So here is my question, is this normal? Is there any way that I can get this thing to slow down the boil?

Ohh 5 gallon batches.

 

[BrunDog]

No. You should not run the boil in PID mode. Run it in manual (aka duty cycle) mode, at approximately 60%.

 

[foy1der]

Thanks for the tip. I just did a boil test with just water, about 6.5 gallons. I switched to manual mode and I brought the water up to about 200F at 100%. Then I dropped it to 60% and the boil raged. Then just out of curiosity, I dropped the percentage down to 1%, and the boil raged on.

Here's where I forgot to mention something. I will say that my system is the absolute bare bones. I found that when I was doing the initial testing, I wanted some way to turn the element off, because when I simply unplugged it, I could get an arc. So I put a simple 110v 15A switch on the 110v power that powers the 24v power supply that feeds the SSR. So I have the ability to turn the element off for sure. If I flip my switch and turn the element completely, meaning there is no way that 24v can go to the SSR to turn the element on, the boil rages.

I will also add that when I was brewing my first electric batch, this switch was off from about 55 minutes all the way to zero minutes. In theory, I kept 5-6 gallons of wort at a boil using no electricity at all.

Further, if I check the voltage across the hots on the element when it is "off", I read somewhere around 300mV. Is it possible that this 0.3V is enough to make my 6 gallons of wort go crazy?

 

[stevehaun]

Sounds like your SSR may have failed closed (as they usually do). Decreasing to 60% power in manual mode should have dramatically decreased your boil and at 1% it should have stopped boiling.

 

[BrunDog]

First of all, do you have a schematic that you used? That would help. Second, cheaper isn't better as you know. So you saved some bucks but got yourself equipment that is not working.

I would do a test to measure the input voltage to the SSR. If the upstream circuit is working, you should have 0V across the input when it is off and >3V when it is on. If that is not correct the SSR is probably shot as noted above by Steve. Switching the power supply on and off is not enough - you need to measure it.

Also It sounds like you do not have a contactor in series with your SSR switched side, so again, money saved may not have been the best goal here.

Plus this makes no sense. Are you certain your brother knows what he is doing: "My brother, who sells automation systems, helped me build it, and told me turn down the gain, that the element was holding heat too much and couldn't dump the heat into the wort fast enough."

Oh, almost forgot. If you think you can keep liquid boiling with no electricity at all - congrats!! You have invented perpetual motion! ;-)

 

[nealm]

Agree on the SSR failure had the same issue. Try shutting the system down for a few seconds then restart at 60% to see if it restarts ok. If so then your SSR is probably overheating. I solved my issue with a fan on the heat sink.

 

[Gameface]

Would really like to see how this is wired.

You put a 110V AC 15A switch on the leg that goes to the 24v DC input to the SSR? Why didn't you put a switch or breaker on the 110V AC leg going into or out of the SSR? That way, even if the SSR fails closed you still have a way to cut power.

Your temp controller isn't a PID, is it? It's a simple thermostatic temp controller?

 

[foy1der]

First of all, do you have a schematic that you used? That would help. Second, cheaper isn't better as you know. So you saved some bucks but got yourself equipment that is not working.

I would do a test to measure the input voltage to the SSR. If the upstream circuit is working, you should have 0V across the input when it is off and >3V when it is on. If that is not correct the SSR is probably shot as noted above by Steve. Switching the power supply on and off is not enough - you need to measure it.

Also It sounds like you do not have a contactor in series with your SSR switched side, so again, money saved may not have been the best goal here.

Plus this makes no sense. Are you certain your brother knows what he is doing: "My brother, who sells automation systems, helped me build it, and told me turn down the gain, that the element was holding heat too much and couldn't dump the heat into the wort fast enough."

Oh, almost forgot. If you think you can keep liquid boiling with no electricity at all - congrats!! You have invented perpetual motion! ;-)

I'll draw up a schematic when I get to work tomorrow.

Perhaps my brother's suggestion makes no sense to you because you have made your own e kettles before and brewed with them more than once. Coming from some one who programs plcs and automation equipment, it seemed a perfectly cromulent suggestion.

I'll check the voltage with the output on and off when I get a chance, I didn't have time to play with it today.

Agree on the SSR failure had the same issue. Try shutting the system down for a few seconds then restart at 60% to see if it restarts ok. If so then your SSR is probably overheating. I solved my issue with a fan on the heat sink.

I can run this test, but I don't that this would be the problem because the symptom only shows up after reaching a boil. It holds water at a given setpoint as long as it is below 212. The next time that I test it, I will feel out the ssr and heatsink for excessive heat.

Would really like to see how this is wired.

You put a 110V AC 15A switch on the leg that goes to the 24v DC input to the SSR? Why didn't you put a switch or breaker on the 110V AC leg going into or out of the SSR? That way, even if the SSR fails closed you still have a way to cut power.

Your temp controller isn't a PID, is it? It's a simple thermostatic temp controller?

Schematic incoming, I'll do it at work tomorrow.

I put a switch on the 120v wire that powers the power supply, not on the 24 volt DC. Also, I did not put a switch on the kettle because I didn't have a 30 amp switch laying around to turn off the power to the kettle, but I know that the power supply draws way less than 15 amps, so a simple light switch could handle it.

Yes the temperature controller is a PID.

 

[BrunDog]

You should switch the output of the power supply, not the input. Some power supplies of of analogue design, will continue to put out power on their outputs despite the input being off if the load is low. An SSR input section has hardly any load, so this might explain why your SSR is not turning off?

 

[FuzzeWuzze]

I'll draw up a schematic when I get to work tomorrow.

Perhaps my brother's suggestion makes no sense to you because you have made your own e kettles before and brewed with them more than once. Coming from some one who programs plcs and automation equipment, it seemed a perfectly cromulent suggestion.

I'll check the voltage with the output on and off when I get a chance, I didn't have time to play with it today.



I can run this test, but I don't that this would be the problem because the symptom only shows up after reaching a boil. It holds water at a given setpoint as long as it is below 212. The next time that I test it, I will feel out the ssr and heatsink for excessive heat.


Schematic incoming, I'll do it at work tomorrow.

I put a switch on the 120v wire that powers the power supply, not on the 24 volt DC. Also, I did not put a switch on the kettle because I didn't have a 30 amp switch laying around to turn off the power to the kettle, but I know that the power supply draws way less than 15 amps, so a simple light switch could handle it.

Yes the temperature controller is a PID.

IMHO you should never be pushing your amperage through your switch. You should be controlling a contactor to control the voltage/amps going to your SSR.

 

[foy1der]

IMHO you should never be pushing your amperage through your switch. You should be controlling a contactor to control the voltage/amps going to your SSR.

That's not what I have done. I'm not sure that we are on the same page, see attached schematic.

You should switch the output of the power supply, not the input. Some power supplies of of analogue design, will continue to put out power on their outputs despite the input being off if the load is low. An SSR input section has hardly any load, so this might explain why your SSR is not turning off?

I don't follow what you are suggesting, can you reference a drawing or mark up my attached?

He is the schematic, I will double check it when I get home. I'm drawing it from memory.

 

[BrunDog]

First, for testing its fine but for production work you don't want an uninterruptible high voltage path through the SSR to the element. They fail on all the time, and short of unplugging the panel you have no means to power it off.

My point above was to switch the incoming power to the SSR low voltage side. Anyway that is moot. Why do you need a 24V supply? I think most PIDs will power the SSR input (low voltage switching side) directly. What model is this?

 

[passedpawn]

PID model number please. I doubt that the 24V supply should be connected directly to the SSR as you have it.

BTW, Home depot sells a 30A 240VAC double pole switch. Mine did, anyway. Look for the following. I use one of these on the wall to shut off all power to by system, and another so I can just disconnect the element, but leave the PID powered. On mine I have a "wet location" cover. Also, see below.

 

[augiedoggy]

auber, rex and mypin pids all run on 24v internally... You feed the 80-240v and they have a small dc powersupply inside that they use to power them at 24v as well as supply the 24v for the ssr switching.. as others have said you dont need the 24v powersupply... also I'm curious.. if it holds 165 degrees fine the ssr is switching fine... sounds like the issue brundog mentioned where there is still DC power stored in the capacitors of the fluctuating DC powersupply your using causing the switch to not turn on and off in real time..

 

[nealm]

The point I was trying to make is that my rig also heated and held mash temp but when I set it to boil the SSR stuck closed and the element stayed on just like your situation. At this time the heat sink was extremely hot. If I shut my system off then restarted it after a few seconds it would function properly in the boil phase. A fan to cool the heat sink helped.

 

[foy1der]

First, for testing its fine but for production work you don't want an uninterruptible high voltage path through the SSR to the element. They fail on all the time, and short of unplugging the panel you have no means to power it off.

My point above was to switch the incoming power to the SSR low voltage side. Anyway that is moot. Why do you need a 24V supply? I think most PIDs will power the SSR input (low voltage switching side) directly. What model is this?

It's a Love Controls 16A, I don't remember the specific model number.

 

[foy1der]

The point I was trying to make is that my rig also heated and held mash temp but when I set it to boil the SSR stuck closed and the element stayed on just like your situation. At this time the heat sink was extremely hot. If I shut my system off then restarted it after a few seconds it would function properly in the boil phase. A fan to cool the heat sink helped.

I'll check that out. Thanks for the clarification.

 

[augiedoggy]

It's a Love Controls 16A, I don't remember the specific model number.

many ssrs have an indicator led on them to see whats going on... if yours does it will help troubleshoot your issue. it almost sounds like your manual mode isnt working correctly. or your ssr is overheating as mentioned above.. You do have it on a heatsink with thermal paste right?

 

[foy1der]

many ssrs have an indicator led on them to see whats going on... if yours does it will help troubleshoot your issue. it almost sounds like your manual mode isnt working correctly. or your ssr is overheating as mentioned above.. You do have it on a heatsink with thermal paste right?

There is a headsink on it, it came installed that way, so I don't know if it has any TIM on it.

The ssr does have an led and when the temperature controller output is off, the led is off, so it should be off, but instead it's "off".

 

[frodus17]

It's a Love Controls 16A, I don't remember the specific model number.

Get the specific model number. It should be the Voltage Output model, not the relay model. Relay versions really are not meant for switching an SSR on and off.

 

[BrunDog]

If you want us to help you, post up all the details: part numbers, schematic (as above), and pictures help a lot. Not trying to be a dick, but I don't want to play 20 questions or be Sherlock Holmes here. Give us all the nitty gritty and we can probably solve your problem quickly.

 

[foy1der]

If you want us to help you, post up all the details: part numbers, schematic (as above), and pictures help a lot. Not trying to be a dick, but I don't want to play 20 questions or be Sherlock Holmes here. Give us all the nitty gritty and we can probably solve your problem quickly.

Fair enough. I didn't have time to run any tests tonight, but here are all the components

SSR: URBest
TC/PID: Love Controls 16A3030
PSU: see photo
Element: Camco 5500w ULWD

 

[frodus17]

That's a relay out pid controller. Not really made for driving an ssr. If you want to use it switch the positive side of that 24v DC supply through the relay. Also make sure your relay is the pid output one and not the second used for the alarm

 

[Bobby_M]

Right, it's not an ideal controller but he IS running a 24v power supply through that mechanical relay. However, I don't think that model has a manual mode but it's such an older unit I can't find the manual. Do yourself a favor and grab a Mypin TD4 on Ebay or Amazon for $25.

 

[doug293cz]

That SSR listing on Amazon has an obvious, sloppy photoedit job to obscure some markings on the faceplate. That's a huge red flag, and I would never buy something with a listing that looked like that.

Brew on

 

[BrunDog]

If the PID is relay out then the schematic is correct. It is odd then that the SSR is not turning off. Again, measure the input with a meter. I think you noted above that the LED on it is correctly switching - which indicates that maybe its cooked.

ultimately, I agree with Bobby - spend a couple bucks and get a modern PID. I don't think it fixes your current problem, but brings you into the modern age.

 

[augiedoggy]

That pid cannot not have manual mode because it would require the mechanical relay to turn on and off so quickly it would burn up in a short period of time... Therefore there is likely a minimum cycle time set that is making the element stay on for longer "cycle" times to protect the relay and prevent it from over heating... this would cause your over boiling issue..

like others have said you need a pid designed to drive an SSR and with manual pwm mode.

As Bobby suggested the mypin td4 snr is a great fit.. its what I use with no issues. you can ditch the 24v supply then too or use it to power a cooling fan for the ssr and some 24v dc 3gpm food grade pumps like these if you dont already have pumps
http://www.ebay.com/itm/251768710886?_trksid=p2057872.m2749.l2649&ssPageName=STRK:MEBIDX:IT
that I use in my setup below

 

[foy1der]

That pid cannot not have manual mode because it would require the mechanical relay to turn on and off so quickly it would burn up in a short period of time... Therefore there is likely a minimum cycle time set that is making the element stay on for longer "cycle" times to protect the relay and prevent it from over heating... this would cause your over boiling issue..

like others have said you need a pid designed to drive an SSR and with manual pwm mode.

As Bobby suggested the mypin td4 snr is a great fit.. its what I use with no issues. you can ditch the 24v supply then too or use it to power a cooling fan for the ssr and some 24v dc 3gpm food grade pumps like these if you dont already have pumps
http://www.ebay.com/itm/251768710886?_trksid=p2057872.m2749.l2649&ssPageName=STRK:MEBIDX:IT
that I use in my setup below

Are there any features that the TD4 doesn't have that I may want in the future? Or is that kind of what everyone uses?

EDIT: with my question in mind, my "cheap" project is over budget and off schedule, so I just want it to work.

 

[passedpawn]

Are there any features that the TD4 doesn't have that I may want in the future? Or is that kind of what everyone uses?

The de facto standard for homebrewers in your sitch is the Auber SYL-2352. Of course, you can go off grid and try different stuff, but there's risk and lack of community support - as you've found out. I've used a couple of these and they work fine.

 

[augiedoggy]

Are there any features that the TD4 doesn't have that I may want in the future? Or is that kind of what everyone uses?

EDIT: with my question in mind, my "cheap" project is over budget and off schedule, so I just want it to work.

As far as I can tell it does everything the auber syl 2352 does but better actually... It has a shorter 1 second cycle time to pulse the element which some will say makes no difference in real world but does allow more percise control over the element power level and gives a more even boil like an ssvr In manual mode. Its easier to switch between the fuzzy/pid and manual pwm mode than the auber unit as well. plus its only $30 shipped from most vendors.
In my opinion the only advantage the auber has is the support is better from auber should you need to contact them.

They are both made in china but Mypin has no dedicated distributor oeming and supporting them.

that said the auber is probably the number one most used pid here and the mypin is #2...

 

[estricklin]

That pid cannot not have manual mode because it would require the mechanical relay to turn on and off so quickly it would burn up in a short period of time... Therefore there is likely a minimum cycle time set that is making the element stay on for longer "cycle" times to protect the relay and prevent it from over heating... this would cause your over boiling issue..

like others have said you need a pid designed to drive an SSR and with manual pwm mode.

As Bobby suggested the mypin td4 snr is a great fit.. its what I use with no issues. you can ditch the 24v supply then too or use it to power a cooling fan for the ssr and some 24v dc 3gpm food grade pumps like these if you dont already have pumps
http://www.ebay.com/itm/251768710886?_trksid=p2057872.m2749.l2649&ssPageName=STRK:MEBIDX:IT
that I use in my setup below

He could also use that 24v DC power supply with the switch he has, to power a relay for the AC wires before they reach the SSR, so that there will be a quick and easy way to kill the power to the heating element in an emergency.

 

[augiedoggy]

He could also use that 24v DC power supply with the switch he has, to power a relay for the AC wires before they reach the SSR, so that there will be a quick and easy way to kill the power to the heating element in an emergency.

yes I do that as well with 25a omrom relays instead of the bigger contactors.

 

[jsbird]

My guess is that your controller is configured to vary the voltage of the signal going the SSR (you described as controlling the "gain"). Therefore, if you set it at 50%, then it sends 50% of the voltage to SSR which would not be enough to switch it off. The duty cycle of your SSR needs to vary the on/off time of the signal going to the SSR, not vary the voltage going to the SSR which would be relay mode. An earlier commenter asked if the SSR LED was cycling on/off when you were in duty cycle mode. If it stays on, then that would support this theory. Measuring the output of the controller when a multimeter while it is cycling would confirm it. That controller does appear to support relay/SSR mode. As I understand it from looking at the Love controller documentation, you set the mode by removing the controller from it's housing and moving the jumper from Output A to Output B. Google for the documentation and look in the Logic Jumper Selection section.

 

[foy1der]

My guess is that your controller is configured to vary the voltage of the signal going the SSR (you described as controlling the "gain"). Therefore, if you set it at 50%, then it sends 50% of the voltage to SSR which would not be enough to switch it off. The duty cycle of your SSR needs to vary the on/off time of the signal going to the SSR, not vary the voltage going to the SSR which would be relay mode. An earlier commenter asked if the SSR LED was cycling on/off when you were in duty cycle mode. If it stays on, then that would support this theory. Measuring the output of the controller when a multimeter while it is cycling would confirm it. That controller does appear to support relay/SSR mode. As I understand it from looking at the Love controller documentation, you set the mode by removing the controller from it's housing and moving the jumper from Output A to Output B. Google for the documentation and look in the Logic Jumper Selection section.

The PID has no jumpers, you must be looking at the wrong manual. The LED does cycle when in duty cycle mode. I haven't had time to play with it recently to measure the voltage across the SSR during duty cycle mode. But the point might be moot because I bought a TD4.