CrossCreekBrewing

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So this is my second go at a diy temp controller. First one i did is on my fermentation chamber, works like a champ. The second one I built is being a bugger. When the ssr is supposed to activate the compressor on the freezer it does perfectly. When the ssr is supposed to turn the compressor on the freezer off, the compressor just runs at a lower power. I unplugged the freezer, plugged in an electric knife, and verified that when the ssr is supposed to flip the power off, it is just trickling out less power (electric knife went from VVVVVRRRRROOOOOOOM!!!!! to vvvrrrooooom. The light on the SSR does go on and off as its supposed to.

Does this make sense to anyone? Bad SSR?

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Primary:Killkenny Red Ale

Secondary:Santa Monica Pale Ale

day_trippr

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Conceivably a bad SSR, but the same symptoms can occur if the "off" control voltage isn't low enough. What are you controlling the SSR with, and have you checked the control voltage level when the SSR is supposed to be "off"?

Cheers!

lschiavo

Recipes 

Does it still run if you disconnect the DC from the SSR?

Exactly what I was thinking...above.

CrossCreekBrewing

Recipes 

5.9V going into the ssr from an old motorola phone charger (attached image), same unit i used on the other working controller. If i disconnect it from the ssr, ssr still does the low power thing (I think thats what you asked, but im not well versed with this stuff, I unethically passed my circuits class in college).

ssr is 3-32vdc


all the cool voltage checking tools are at my pops garage, wont be able to check that til the weekend.

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Primary:Killkenny Red Ale

Secondary:Santa Monica Pale Ale

lschiavo

Recipes 

If the SSR is passing current with no input signal, it's gotta be bad I think.

BTW, your use of sound effects was a great help Seriously.

MaxOut

Recipes 

Are you switching the hot or neutral through the SSR?

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MaxOut Brew Station on HBT

MaxOut Brew Station on AHA

CrossCreekBrewing

Recipes 

I will double check taht when I get home from work, but I am fairly confident I am switching the hot side. If i had it backwards, could that be the problem?

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Primary:Killkenny Red Ale

Secondary:Santa Monica Pale Ale

shortyjacobs

Recipes 

SSRs have low leakage current, but that shouldn't be enough to trigger your e-knife or fridge. They typically only leak a few milliamps, not enough to run anything.

Is the SSR on a heat sink? Is the heatsink getting hot? My SSR was failing closed and heating up a lot, required me to buy a new SSR, (link to my thread:http://www.homebrewtalk.com/f170/how-hot-should-ssr-run-sign-doa-one-290938/).

Does your PID have a relay output? I'd ditch the SSR entirely, and use a contactor relay....much more suited to this type of operation. You can get one for about $10 shipped off of amazon.

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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.

CrossCreekBrewing

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"Does your PID have a relay output?"
what would the PID be?(wearing my dunce hat here)

can you provide a link to a contactor relay? really appreciate it if you can.

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Primary:Killkenny Red Ale

Secondary:Santa Monica Pale Ale

CrossCreekBrewing

Recipes 

and no, not on a heat sink, my original one never gets hot, and this one isn't ever getting hot either.

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Primary:Killkenny Red Ale

Secondary:Santa Monica Pale Ale