shortyjacobs

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I'm working on getting my new brewery up and running. Did my first autotune try today.

I gave two AT tries, one from 50F to a SV of 165F, and one from 145F to a SV of 165F. The first time, the temp overshot to 208, at which point I shut it down. The second time, it overshot to 195, at which point I shut it down.

40A SSR w/ standard heatsink, 5500W element pulling ~23A IIRC, SYL-2352 running the SSR.

Wiring diagram here: http://www.homebrewtalk.com/f170/diagram-critique-my-brutus-20-10-a-279903/

Once the PID passed the SV during the autotunes, the "on" light on it shut off. So did the LED on the SSR. But the element was pumping out heat. Not as much as before, when the PID was at 100% for the AT, but it was still boiling water. When I power cycled the Line/Load side of the SSR, that fixed the problem and allowed the system to start cooling.

So it looks like my SSR is sticking "on". Power cycling it after it's stopped getting a control signal unlatches it, at least that's the way I read it. OH, and the SSR heatsink is frigging HOT during all this, (even once the SSR has supposedly shut "off"). Like we're talking burn your skin hot. It's in an open box with plenty of ventilation.

So, blown SSR?

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(As of 10-24-2011)
Primary - Steppe 112 PA, 2x Monday RyePA
Aging - None :-(
On tap - Big Dog, Apfelwein, Steppe 112 PA

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IrregularPulse

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IrregularPulse

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I'd say either the SSR stuck on or the PID control signal stuck despite the LED going off. You'd need a voltmeter to confirm which. I've not really looked at the schematic as I just woke up from a nap and honestly don't feel like thinking. It's always good to double check wiring though. When you built it, did you wire everything at once? Or wire one circuit, test, wire one circuit, test etc.?

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shortyjacobs

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Thanks Irregular Pulse, I suppose I should have posted the pic...you actually chose an earlier iteration from that thread. Here's what it is now:


Coderage, first time I turned it on was when the wiring was all done. I suppose I'm going to to have to man up and give it full power while it's open so I can test with a multimeter....carefully. That bit scares me .

(click pic above for bigger)

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Itchy Dog Brewery.

(As of 10-24-2011)
Primary - Steppe 112 PA, 2x Monday RyePA
Aging - None :-(
On tap - Big Dog, Apfelwein, Steppe 112 PA

My invisible AG sculpture, with no actual sculpture and a tiny footprint.
My Kegerator goes offroading!
My Coors Home Draft dispenser for boating/beering on the go.

Stevo2569

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Sounds like a wiring problem or defective SSR. I don't know how common that is. I just got mine installed. My SSR heat sink was running hot as hell. See sig for fix.

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samc

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My 40 amp SSR's get to about 120F when things are running 100%, they are outside the box. Can you swap the SSR's to test?

bf514921

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random thought is there anyway to turn on the system but not turn on the heating element? see if it is heating at the start, see if it is a wiring problem and not the ssr?

bf514921

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almost sounds like the element is still running on 120

shortyjacobs

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Yeah, mine are definitely way above 120F. Based on sticking my hand in 146F water, I'd say they're pushing 150-160F. (this was pushing 100% too, since in AT it runs 100% or 0%). I can't swap SSRs with any degree of happiness....the other is a 25A SSR....I don't like running it that close to redline...


Not sure I follow. I can hit the disconnect on the latching relay that provides power to the Line/Load side of the SSR, and when I do that the element definitely goes dead. I can shut off the PID providing control voltage to the SSR, and when I do that I'm PRETTY sure the element stays live, (I think, I need to check this tomorrow).

My thoughts too...seeing as it was only pumping out partial power and not full power....but there's no way that element can see neutral....

Yeah, definitely gonna be mounting a fan in there, regardless of my current problem.



Thanks for the responses folks. Tomorrow, if I get a chance, I'm gonna fire it up live and get in there with a multimeter....hopefully get more info.

__________________
Itchy Dog Brewery.

(As of 10-24-2011)
Primary - Steppe 112 PA, 2x Monday RyePA
Aging - None :-(
On tap - Big Dog, Apfelwein, Steppe 112 PA

My invisible AG sculpture, with no actual sculpture and a tiny footprint.
My Kegerator goes offroading!
My Coors Home Draft dispenser for boating/beering on the go.

frankstoneline

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I recently had a similar problem, make sure your PID is not in the manual mode (where you select a %value). Mine was somewhat confusing initially, however when i eventually got it set in its PID mode the auto tune worked fine.

Edit: I re-read your initial post, and it seems doubtful my above suggested situation is what you have, especially if the elements output decreased after reaching the set value.

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