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Just wondering how others have done this? I have 2 ssr's with the small heatsinks like shown below, I was thinking that the ssr would be in the box and the sink outside with a hole in the panel for the connection but there doesnt seem to be much of a lip on these to hold them in place. Any advice?

I did what you are doing. The sink should be threaded, maybe metric screws, so you just run 2 holes through the box and screw the pieces together.

I mounted mine inside my panel knowing that it could generate too much heat with the idea that I would change it if it became a problem. No problems or a noticable amount of heat so far. YMMV and I'm only using one.

mr x wrote:I did what you are doing. The sink should be threaded, maybe metric screws, so you just run 2 holes through the box and screw the pieces together.

so the metal box is between your ssr and the sink? I thought they had to be together?

Yup, and it's OK AFAIAC. There is heatsink compound that is supposed to add to the heat transfer, but I think you'll be ok without it.

Might want to remove the paint on either side of the box in that case too.

Sent from the brew timer.

I have the same setup SSR->Painted SS->Heat Sink, the heat sink works great (probably raises up to +10c above ambient at max) I just bolted through the entire setup and it's screwed down tight.

If you notice the heatsink is a little larger than the SSR. I cut a hole in my box that is just big enough to alow the SSR to go through, but the heatsink rests on that shoulder. Then I JB Welded the crap out it it. Worked like a charm.

Want to finish my box when you're done with yours? lol

I tried looking up a datasheet on the Fotek website and it's pure crap... haha. Absolutely no thermal data on there whatsoever. There should at minimum be a temperature derating curve. Nor was there any case to junction temperature data. If it were me, I would just measure the case while running things at full bore and see how hot it gets. I'm sure it will work regardless, but if you are running it extremely hot, it could drastically reduce the life of the SSR.

That aside, best practice would be to mount the heat sink with thermal compound directly to the heat sink. Also, if you're going to mount the SSR to the panel and a heatsink to the back of the panel, I agree with rubbertoe - remove the paint, and better yet, use thermal compound as well. Every connection creates a thermal impedance. So what thirdeye is suggesting would be: Junction->case->air->paint->panel->paint->air->heatsink. The thermal impedance of air is much greater than that of thermal compound.

Anyway, I know it probably sounds like I'm over complicating it, but minor details like making sure your parts are adequately rated of the conditions can mean a lifetime of trouble free operation versus changing out parts every couple of years.

I'm dealing with the same issue now, and I think I will order a custom heat sink from HeatSinkUSA to address this. A custom cut 10"W x 3.5"D heat sink runs only about $11 plus shipping. Tapping still up to you, though.

http://www.heatsinkusa.com/3-500-wide-e ... -heatsink/" onclick="window.open(this.href);return false;

Current Electric Brewery status: back plane all wired, almost finished machining my enclosure. Super excited to paint it and wire the controls.

If you hold off for a day, I might be able to find something for you in my junkpile....

mr x wrote:If you hold off for a day, I might be able to find something for you in my junkpile....

Just seeing this.. I appreciate the offer. I've ordered the other heat sink already.