How can I tell if my SSR is going out? And what is a "good" one.

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homebrewdude76

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I have a 3 element system, with cutoffs to allow 2 to run at a time.
I brew alot... 2-3times per month, 20gal at a time.
These SSR's, which were just whatever was on Ebay are all original.

Yesterday one was not firing the element. I have a panel light that lights when the SSR fires, I was getting blips of light but no real amperage draw.
So I had to move my element to anthor branch and it all worked fine.

Today I tried to use the "bad" SSR again, and from what I can see it works fine.

Is it going out? I want to buy some "spares" now. Any suggestion on where to get them?
 
You get what you pay for and a lot of cheap, SSRs are counterfeit. I run a similar, 3 element system and all of my SSRs started to fail about the same time. I've replaced most of them with Inkbird branded ones. I can't tell you how long they will last, but I've been using them for a while. The price is good and they are a vendor here.

https://inkbird.shop/products/ssr
 
Is it better to bump the size up on these? 25a vs 40a ?
I am running 5500watt elements.
Yes. It's almost always better to use electronic components that are rated significantly higher than their intended use conditions. A 5500W element will draw ~23A @ 240V. 25A isn't really enough of an operating margin.

SSR's have a tendency to latch in the "On" state when they over heat. If your SSR's are correctly grounded, then it is safe to touch the heatsinks while in operation. They should not be so hot that you can't hold your hand on them.

Are your "element firing" lights wired in parallel to the element power feeds, or in parallel to the SSR trigger signals? The first is the correct way to do it.

If your SSR's are actually triggering on, but no current is being drawn, that would indicate an open circuit in the element loop, most likely.

Brew on :mug:
 
I am doubting its the element. I plugged the element into another port and it worked fine for the brew day.

My SSR has an LED that is the signal from the PID. That is flashing in sync with the PID. So it looks like the SSR knows to fire .
My element on light is inside with the element power, so when that light is not on its not firing the element.

I ordered a new SSR, plan on swapping it.
 
I noticed this today.
A burnt wire from my breaker to contactor that allows the element to work.

Wonder if the contactor went bad?

20210119_121219.jpg
 
Definitely an overheated connection. I'd replace the contactor and any damaged wires. Make sure the connections are tight on the new contactor.

Connections can work loose over time due to thermal cycling inside the enclosure. It's good practice to periodically go thru and re-torque all screw type connections.

Brew on :mug:
 
And just why are you using expensive SSRs? Electromechanical relays are dirt cheap, and in your application will last years and years. Sure, they are cool and fun technology, and if that's what you want, go ahead and pay the extra bucks. When you are dealing with that much liquid volume for temperature control, you can cycle the relay over a 5 minute interval and still have very precise control. If you have a cheap EM relay that will last 100,000 cycles, that is still a year of continuous operation. Most cheap relays do quite better than that, and good ones will probably last 10X that long.
 
And just why are you using expensive SSRs? Electromechanical relays are dirt cheap, and in your application will last years and years. Sure, they are cool and fun technology, and if that's what you want, go ahead and pay the extra bucks. When you are dealing with that much liquid volume for temperature control, you can cycle the relay over a 5 minute interval and still have very precise control. If you have a cheap EM relay that will last 100,000 cycles, that is still a year of continuous operation. Most cheap relays do quite better than that, and good ones will probably last 10X that long.
5 minute cycle times are way too long when some systems are capable of heating rates of about 1 deg/minute.

Many PID's have PWM cycle times of 1 - 2 seconds. And Auber EZBoils have cycle times of 16.7 mSec. Longer cycle times might work for mashing, if you can keep the wort from overheating around the element (which can denature the enzymes, and may cause scorching.) Also, mechanical relays capable of handling 25A aren't much cheaper than SSR's.

And if mech relays are such a good fit for brewing applications, why are there no commercial systems that use them instead of SSR's?

Brew on :mug:
 
This thread made me think............how do you ground an SSR? I'm assuming people mean if they're using a metal enclosure, and the aluminum heatsink is attached to the encloure, then the heatsink is grounded thereby making the SSR grounded?

I've got a plastic enclosure, with an aluminum heatsink, so maybe i should be running a ground wire to the heatsink in this case? Never even thought about it. Not that i touch the heatsink at all. just the first time i ran the new panel just to see how hot it got
 
This thread made me think............how do you ground an SSR? I'm assuming people mean if they're using a metal enclosure, and the aluminum heatsink is attached to the encloure, then the heatsink is grounded thereby making the SSR grounded?

I've got a plastic enclosure, with an aluminum heatsink, so maybe i should be running a ground wire to the heatsink in this case? Never even thought about it. Not that i touch the heatsink at all. just the first time i ran the new panel just to see how hot it got
Yes, having the heatsink grounded is a good idea.

A ground wire on one of the mounting bolts/screws that contacts the SSR base plate is a good way to ground both the SSR and heatsink (assuming the mounting hardware contacts both.)

Brew on :mug:
 
Yes, having the heatsink grounded is a good idea.

A ground wire on one of the mounting bolts/screws that contacts the SSR base plate is a good way to ground both the SSR and heatsink (assuming the mounting hardware contacts both.)

Brew on :mug:
Thanks Doug. Dont know why i never thought about the heatsink. I'll tie a ground off the mounting screw to my grounding bar before my next brew!
 
When you are dealing with that much liquid volume for temperature control, you can cycle the relay over a 5 minute interval and still have very precise control.

My kettle heats a 100F rise in 18 minutes. Even a 1 minute cycle time would be an oscillating disaster. That doesn't really matter because the boil control operates on a very fast PWM and I wouldn't want to hear a mechanical relay clicking even every second, nevermind...
 
Not sure why this went sideways to talking about a relays??

Anyway, all parts replaced on my #1 circuit, going to brew this weekend.
 
Mechanical relays wont hold up very long when clicking on and off multiple times per minute.. The contacts heat up this way and eventually fail by either fusing closed or burning/damaging the contact surface causing the current not to pass reliably. This weakness is literally one of the reasons SSRs exist.

In regards as to which brand to buy?.... well you should be safe with pretty much any correctly sized/rated SSR except the Fotek branded ones ... There are more counterfeit clones out there of the fotek branded ones than real fotek ssrs so your chances of having issues are much higher if you buy these.

In this case My money is on the problem being that contactor connection being the problem.
 
I ended up swapping the contactor and repairing the wire. Brewed twice this weekend no issues.
Looks like the contactor failed, not the SSR
 
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