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Bernard Eloff

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Hi Guys

I am building a HERMS brewery and using a Raspberry Pi with CarftbeerPi. I am ready to test the setup. When I set a target temperature and hit the car button the HLT element turns on, but when it reaches the target temp it does not turn off. I am a serious noob when it comes to this kind of stuff. Is there anyone here that can offer some advice?

Regards

Bernard

Pic1.jpeg Pic2.jpeg
 

doug293cz

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It's possible your SSR is over heating and latching in the "on" mode. "Fotek" SSR's are notorious for being manufactured with undersized TRIAC's, which makes them very prone to the heat latching failure mode.

Heatsinks depend on air flow around them to do their job. Since you have mounted your heatsinks internal to the enclosure, they will get insufficient air flow. I'm not trying to be cruel, but from a thermal standpoint, your design is terrible. If you want advice on how to improve it, just ask. But, it will require significant rework of your layout to get good thermal performance.

Brew on :mug:
 

rkhanso

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If you're just running one of those SSRs as a test, I'd be inclined to think that there's enough heat dissipation capability to run one SSR at a time. I'd also agree with doug293cz that if you're running all of those at the same time, you may likely run into some overheating trouble.

FWIW - I had some trouble with my SSR operating the way I expected (I only have one in my controller). I'm NOT a programming guy and have a steep learning curve in how to set up CBPi and all the options for hardware logic, etc. I did have a somewhat similar situation that you explained when I chose incorrect, or not-compatible logic between the Kettle and the Heater. I discovered that some (all?) need to match in pairs. You may want to experiment or read up on logic options and see if you can get the SSR to behave in a more expected manner.

Example - I currently have my Kettle and Heater logic set to Mod_PWM.
You may want to try other combinations as well and then test.
Maybe PIDBoil or SimpleBoilLogic on the Kettle and GPIOSimple on the Heater.

Again - I'm in no way an expert and learn most by trial and error. So I may be off base.

FYI - Here's a picture of my Controller, with the heat-sink outside the box.

IMG_20171215_094250.jpg
 
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jtrainer

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If you're just running one of those SSRs as a test, I'd be inclined to think that there's enough heat dissipation capability to run one SSR at a time. I'd also agree with doug293cz that if you're running all of those at the same time, you may likely run into some overheating trouble.

FWIW - I had some trouble with my SSR operating the way I expected (I only have one in my controller). I'm NOT a programming guy and have a steep learning curve in how to set up CBPi and all the options for hardware logic, etc. I did have a somewhat similar situation that you explained when I chose incorrect, or not-compatible logic between the Kettle and the Heater. I discovered that some (all?) need to match in pairs. You may want to experiment or read up on logic options and see if you can get the SSR to behave in a more expected manner.

Example - I currently have my Kettle and Heater logic set to Mod_PWM.
You may want to try other combinations as well and then test.
Maybe PIDBoil or SimpleBoilLogic on the Kettle and GPIOSimple on the Heater.

Again - I'm in no way an expert and learn most by trial and error. So I may be off base.

FYI - Here's a picture of my Controller, with the heat-sink outside the box.

View attachment 593154
Can you share a few more detailed pics for me of your box?

I'm planning on a small 2 relay board for my freezer and possibly my kegerator. Your box appears to be the same cantex box I picked up.

How are your temp probes connected, pass through or are those actually some sort of ethernet jack?
Which breakout hat is that?
Finally, powering the Pi, is that the black two wire from the top?
 

rkhanso

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I have a few different kinds of jacks in my box.
On the bottom of the box:
Obviously, the 240v jack for the heat element.
There are 3 locking RCA jacks for temp probes (tip, ring, sleeve)
There is one locking RJ45 jack to power the small 12v pump. It's run off the relay inside the box.
I have the Terragady 4.2 board on the Pi.
There is a buzzer/alarm mounted between the red and blue indicator lights.

On the right side of the box is the 12v DC input from the wall adapter.
On the left side of the box is the 240v AC input to the SSR.

I changed the pump fuse since that picture was taken and mounted an outside accessible auto-type fuse.

Here are some current pictures:

IMG_20181018_113802825.jpg IMG_20181018_113812811.jpg IMG_20181018_113819947.jpg IMG_20181018_113832078.jpg IMG_20181018_113843969.jpg IMG_20181018_113851899.jpg
 

golfindia

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I'd put a contactor in there somehow or at least a small switche to turn off the low voltage control signal to that SSR. When (not if) you have an emergency and need to shut off the heater quick it's tough to do it fast enough clicking the software.....
 

rkhanso

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I'd put a contactor in there somehow or at least a small switche to turn off the low voltage control signal to that SSR. When (not if) you have an emergency and need to shut off the heater quick it's tough to do it fast enough clicking the software.....
I thought about that but didn't bother. I've read where the SSRs usually fail in the ON position and killing the LV signal wouldn't do anything anyway. Plus, where I brew is right next to both the 50A breaker in the Spa Panel and the 30A breaker in the sub-panel....so - two breakers right there where I'm brewing.
The indicator light is powered off the load-side of the SSR, so if the indicator is on the heater or pump is energized.
 

golfindia

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Work on your reading comprehension. I said "AT LEAST". You can do it how you want, I'm just stating some facts.
 
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rkhanso

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Work on your reading comprehension. I said "AT LEAST". You can do it how you want, I'm just stating some facts.
Thanks for looking out for me.
I understand what a contactor / emergency shutoff does. And I did consider it.
But since I have two circuit breakers and a GFCI as close to the kettle as my controller box is, one more safety switch in the path wasn't going to get me much more than I already have. You can see the SPA panel next to the controller in a couple of the pictures. The sub-panel is just to the right of the Spa panel. There are breakers for the heat element in both of them already. Not worth the cost for a contactor in my situation - in my opinion.


I suppose your suggestion was for the original poster, who would have to determine that for himself. If there are no other shutoff options near his controller box, I would suggest the same for him to add an emergency shutoff to his box. It appears that he has the room for it.
 
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