Burner not shutting off

[MFigz]

I'm running a 220 volt water heater element connected to an Aubur ezboil PID. When I turn the system on, the temp shoots right past my set value and doesn't shut off.

The odd part is, if I wait until the actual temperature is within 5 to 10 degrees Fahrenheit of the set value (or I overshoot the set value), the system works like a charm. I've replaced the PID and the SSR but I still I'm having the problem. Does anyone have any idea what could be causing this?

 

[doug293cz]

Need more information. Things that would help:

• Element power rating
  
• Control system circuit diagram
• Photos of your system showing location of temperature probe
• Photo of SSR and heatsink assembly (in place)
• What is the "Output" light on the EZBoil doing while the system is overheating?
• How do you go about getting your temp to withing 5 - 10 degrees without running the control system?
• Description of process where the overshoot is happening, i.e. just heating strike water, recirculating during mash, other?

Brew on

 

[BeardedBrews]

Doug is right on needing details, but I had the same symptom in my build. The SSR was overheating which causes it to"stick" on.

A better heat sink or better thermal paste will help get the heat out faster. A better SSR will generate less heat to begin with. You can do either or both.

 

[MFigz]

Sorry, I will answer what I can now and answer the rest later tonight or tomorrow along with uploading pictures and diagram. I forgot one very important detail. The system will heat at 100% power and keep heating past my set point. The part I forgot to add was that if I flip the burner switch on and off when I get close to the set point (or after I overshoot it) the system works fine. Typically it happens when heating strike water or when I use mash mode to get me close to the boil so the hot break doesn't sneak up on me.

As for the ezboil light, the output light slows down and then turns off as the temperature hits the set point, but the heater element keeps heating. This makes me wonder if BeardedBrews point about the SSR sticking might be my problem?

 

[doug293cz]

Sorry, I will answer what I can now and answer the rest later tonight or tomorrow along with uploading pictures and diagram. I forgot one very important detail. The system will heat at 100% power and keep heating past my set point. The part I forgot to add was that if I flip the burner switch on and off when I get close to the set point (or after I overshoot it) the system works fine. Typically it happens when heating strike water or when I use mash mode to get me close to the boil so the hot break doesn't sneak up on me.

As for the ezboil light, the output light slows down and then turns off as the temperature hits the set point, but the heater element keeps heating. This makes me wonder if BeardedBrews point about the SSR sticking might be my problem?

Definitely sounds like SSR latching issue. Here's where photos of how you have the SSR/heatsink mounted would help us give you ideas about just what causes the overheating and latching.

Brew on

 

[BeardedBrews]

The SSR makes heat proportional to the power going through it. When you're getting the temp up on the strike water it's chugging away at 100%, heavy power on the SSR and lots of heat so it can stick. When it's maintaining temperature it's only running at a few percent, less heat. If you turn it off and back on you can unstick it and it should maintain fine until you do the next temperature ramp.

The downside is that a sticky SSR is one that's going to fail. When I took mine out and replaced it I broke open the cover and discovered that the components inside were not rated the same as the label on the front. It's a risk when we get the cheaper import parts.

 

[MFigz]

Great! Basically, the SSR is mounted in the top of the control box and the heat sink is outside the box. I do not have a fan for the control box, and I can't remember, but there may not be any thermal paste between the heat sink and SSR come to think of it... I'm guessing that might be a good place to start .

 

[MFigz]

Do you have a recommendation for a good quality SSR? I think I may just replace it and buy some thermal paste to be sure about it. I think the last one was 10 to $15 on Amazon and I think it might not have come with paste and I didn't have any so I rolled the dice.

 

[BeardedBrews]

Thermal paste would be a great start.

As far as a better unit there are three approaches.

For $20 you could probably find an import 100amp SSR. The internals on that are probably only actually rated for 25 amps but fortunately that's basically what you need.

For the same $20 you could take a shot on a 40 amp Picker PCS15 which I have heard is more reliable but I've never tested.

Or for $60 you can get a proper crydom 2450 from a local industrial supply house. I went with this route using surplus stock from work, no issues since I installed.

 

[doug293cz]

I have also not heard of failures with the Mager SSR's that you can find on eBay for reasonable prices. The model you want is "MGR-1 D4840"

https://www.ebay.com/itm/Mager-40A-...244314?hash=item5b2516545a:g:MWoAAOSwo0JWJzxJ
https://www.ebay.com/itm/Mager-SSR-...867853?hash=item211b88c0cd:g:rF4AAOSwgTJbI1sn​

Brew on

 

[golfindia]

All the chinese SSRs are made in one or two factories in China. They are all essentially cheaply made "clones" with different stickers and sketchy QC. The real killer of all SSRs is heat. Those upside down triangular black heat sinks they usually come with are useless. Most of the heat sinking mass is not even touching the SSR. Get a big chunk of Aluminum and drill/tap a couple holes to mount the SSR to it.

I have several of these with 2 SSRs on them (even Foteks). Never had any SSR problems.

https://www.ebay.com/itm/ELEGIANT-Cooling-Module-7-1x3-9x1-8inch-Aluminum-Heat-Sink-Heatsink-Cooler-F/322416441961?_trkparms=aid=111001&algo=REC.SEED&ao=1&asc=20180105095858&meid=9e6d9263c13d499ab9dc6c523a669251&pid=100904&rk=2&rkt=20&sd=372662825555&itm=322416441961&_trksid=p2509164.c100904.m5276

 

[processhead]

Crydom and Opto 22 are both quality brands of SSR. I have no reservation using either and will pick up new or used ones when ever I get a chance.
In my panel, I am using the inner 14 x 16 x 1/8 inch steel back plate as the heat sink for both SSRs. I initially had reservations about this being enough surface area to dissipate the heat, but it has never been an issue.
I have one of each brand in my panel. Going on 10 years now with no issues ever. Yes, they are more expensive, but definitely worth it IMO.

 

[Soulshine2]

I'm running a 220 volt water heater element connected to an Aubur ezboil PID. When I turn the system on, the temp shoots right past my set value and doesn't shut off.

The odd part is, if I wait until the actual temperature is within 5 to 10 degrees Fahrenheit of the set value (or I overshoot the set value), the system works like a charm. I've replaced the PID and the SSR but I still I'm having the problem. Does anyone have any idea what could be causing this?

When you set the perameters ,did you "save " the settings?