Bad SSR? DIY temp control

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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?
 
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!
 
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.

photo-2.jpg
 
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?
 
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:https://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.
 
"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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