PID SSR stuck

[aeviaanah]

I have a PID controlling cleaner temp in keg washer. SSR is showing off but is stuck open causing overheat issues. Even with the installed heat sink, my issue may be caused by excessive heat or poor SSR. I bought a 5 pack on Amazon and most of them show the same symptoms. Heatsink and SSR are both internal to the panel but I'm seeing the issue even with the panel door left open.

I either need to swap out for a PID with contactor/relay output or find a better SSR. Thoughts? Perhaps oversizing the SSR would help?

 

[Jayjay1976]

SSR's typically fail in the closed position. I'd recommend buying better quality from a reputable source. Good quality doesn't come so cheap.

Also, use adequate heatsinks and fans to keep them cool.

 

[cfrazier77]

Even good ones can fail. But, get a good one and have a spare. I have a indicator light for the element firing on my rims controller. This is how I found out mine got stuck. This was after 7 years of use, not bad.

 

[Jayjay1976]

Even good ones can fail. But, get a good one and have a spare. I have a indicator light for the element firing on my rims controller. This is how I found out mine got stuck. This was after 7 years of use, not bad.

Damn, an indicator light is a great idea. Is it simply wired in parallel with the element?

 

[doug293cz]

Damn, an indicator light is a great idea. Is it simply wired in parallel with the element?

Yes, the element firing light is wired in parallel with the element. All my designs include one.

There is a quirk with the element firing light, in that it will light up if the element is disconnected, even when the SSR is off. This is an artifact caused by the "off" leakage current of the SSR.

Brew on

 

[doug293cz]

Even good ones can fail. But, get a good one and have a spare. I have a indicator light for the element firing on my rims controller. This is how I found out mine got stuck. This was after 7 years of use, not bad.

I highly recommend an "element firing light" in parallel with the element for exactly this reason.

Brew on

 

[aeviaanah]

I dont need the accuracy a PID/SSR provide but panel is already cut for a standard PID. Do you know of a thermostat with same form factor as a typical PID but built to suit contactor (without the rapid cycles SSRs use)?

 

[Jayjay1976]

I dont need the accuracy a PID/SSR provide but panel is already cut for a standard PID. Do you know of a thermostat with same form factor as a typical PID but built to suit contactor (without the rapid cycles SSRs use)?

An inkbird PID is so cheap, why not just use one of those?

 

[cfrazier77]

Damn, an indicator light is a great idea. Is it simply wired in parallel with the element?

Correct, it is easy to do and Doug is right, with the element unplugged it will stay lit.

 

[aeviaanah]

An inkbird PID is so cheap, why not just use one of those?

I'm attempting to overcome cheap SSR and or overheat issues since it's mounted inside a small panel. I'd use a cheap PID if it can be quieted for use with contactor

 

[doug293cz]

I'm attempting to overcome cheap SSR and or overheat issues since it's mounted inside a small panel. I'd use a cheap PID if it can be quieted for use with contactor

Mounting a heat producing component inside a small enclosure with no fan is a recipe for overheating. SSR's can latch up (get stuck on) when they overheat. I'd look at putting the heatsink out in the open air, or adding a fan in the enclosure, along with air inlets and outlets (fan should be mounted to either inlet or outlet.)

Brew on

 

[Beer666]

I highly recommend an "element firing light" in parallel with the element for exactly this reason.

Brew on

At the risk of sounding like a moron is there a wiring diagram anywhere and what sort of light would i need? Thanks

 

[doug293cz]

At the risk of sounding like a moron is there a wiring diagram anywhere and what sort of light would i need? Thanks

Here's a simple schematic that shows an "element firing lamp." Here is a link to a suitable lamp. If you are running the element at 120V you want a 120V LED, and likewise 240V for 240V. You can substitute any equivalent lamp - you don't have to use Auber as a source. Lamps just have to be rated for the element operating voltage, and AC current.

Brew on

 

[aeviaanah]

Mounting a heat producing component inside a small enclosure with no fan is a recipe for overheating. SSR's can latch up (get stuck on) when they overheat. I'd look at putting the heatsink out in the open air, or adding a fan in the enclosure, along with air inlets and outlets (fan should be mounted to either inlet or outlet.)

Brew on

It's getting stuck open in an open panel when it's 50deg outside. Not much usage either

 

[doug293cz]

It's getting stuck open in an open panel when it's 50deg outside. Not much usage either

If you are getting overheating of your cleaning solution, then the SSR is getting latched "closed" or "on," not "open."

Brew on

 

[Jayjay1976]

Buy a new SSR, put a fan on the heatsink, you'll be fine.

 

[aeviaanah]

Put a new SSR and all is well!