# SSR Mounting



## Adr_0 (6/4/15)

I always seem to see heatsinks mounted inside boxes with SSR's which is ugly (and probably not the best for SSRs) or we see the SSR outside the box which exposes the 240V terminals to being touched which isn't best practice.

I have attached some photos of another way to mount the heatsink and SSR which hopefully achieves the best of all worlds: terminals safely inside the box, heatsink out in the open, and direct coupling of the SSR to the heatsink.




I have the mounting holes in the heatsink and just have to do the final alignment of everything before drilling these through the box.







The hole was just marked with a square/nikko, cut out with a dremel and finished with a couple of files.

This is only a 20A SSR, but I'm using a 2kW element (probably only need 1500-1800) in the recirc loop of my system. HLT/kettle is gas fired. Strike water will be heated to within 90% of temp and then fine-tuned with the element and PID.

Heatsink and SSR are from element14 (au.element14.com), part numbers:
Omron 20A SSR (12V DC pulse input) - 1181260 - $32.07
Heatsink, 1.5°C/W 100 x 97 x 25mm - 4621529 - $11.15

Orders $45 and over get free next-day shipping. So you can pick up some glands and an enclosure while you're there and have everything within a couple of days.


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## Camo6 (6/4/15)

That's how I mounted mine and as illustrated in the Electric Brewery build.





A couple of things to add are make sure you earth the SSR base and use some thermal paste for effective heat transfer between SSR and heatsink.


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## Adr_0 (6/4/15)

Ahhh, like this:
http://www.theelectricbrewery.com/control-panel-part-1?page=6

Very good, carry on.  Glad to see most people are doing it properly.

The SSR/heatsink will be earthed, and there will be an earth down to the element termination box (65x65mm aluminium). Cold weld paste doesn't conduct electricity (I'm guessing because you would get galvanic corrosion if it did) so I will probably put an extra earth bond to the element nut, but I'm still not 100% convinced I will get good conductivity to the RIMS tube so I may tack on a separate earth.


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## takai (14/4/15)

I thought this was how it was always done. The only few i have cringed over were ones where an SSR was simply screwed to the side of a Decor box...


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## Eagleburger (14/4/15)

If mounting to a steel or aluminium case like the last pics, omit the heat sink and directly mount to case. Nice big heatsink that case. I used a large chunk of aluminium angle as heatsink for my few controller builds.


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## QldKev (14/4/15)

The through the wall heat sinks are great, but don't discount the rack mount style. On my 3V's brew controller I went the internal rack mount to keep them out of the way, and out of the way of dust. Also since I'm running 6 x SSRs that would be a lot of cooling fins. But I did include a fan with dust filter to ensure airflow through the box.


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## elcarter (14/4/15)

Heat sink on my internal SSR and a case cooling fan worked a treat in my setup.

The joys of being an ex commuter geek so much stuff to re-use.


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## MartinOC (14/4/15)

:icon_offtopic:


elcarter said:


> The joys of being an ex *commuter *geek so much stuff to re-use.


You recycle trains??


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## elcarter (14/4/15)

Ha no but may need to change the batteries on the wireless keyboard for the htpc.

I do have an old hornsby train set... No SSR's there.

Fans at the front covered with reused old case wire mesh from a coolmaster case.


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## dicko (14/4/15)

Hornby..... Isn't it...
I had a Hornby Dublo aa guage set when I was a boy.
Great english quality. 

I do remember a funny thing as kids do sometimes....A mate of my Dad came to our place when I had the train set in the lounge room and when he saw the box he said... ah! Hornsby to Dubbo.... must be a good train set!!

In those days we weren't allowed to laugh outwardly at adults so I had to hold it in. Not now though. Hahahahahahahaha!!!!!  

Back to brewing


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## MartinOC (14/4/15)

I can see the meshed



elcarter said:


> Fans at the front covered with reused old case wire mesh from a coolmaster case.


Cool, mate (pardon the obvious pun!!), but where's the outlet for the escaping "hot" air in your control box?


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## Adr_0 (14/4/15)

Yeah, looks like most people do it well. I had seen people using fans to draw out the hot air, but this was the kit that I bought:



It's a handy kit, but the SSR is not compatible with PID's. The kit does not have a flush-mount heatsink as you can see, and the installation instructions recommend installing inside the SSR/heatsink inside the box (drill a few holes and she'll be right...).

And it probably will be right to be be honest, though I'm driving ~9A with a 20A SSR so it's probably in the range where it's getting hot.


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## jlmcgrath (14/4/15)

Camo6 said:


> That's how I mounted mine and as illustrated in the Electric Brewery build.
> 
> 
> 
> ...


How do you go about grounding the base of thee SSR? Are you adding a ground post to the heatsink?


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## Camo6 (15/4/15)

Hey Jlmcgrath, thine SSR should have exposed metal at the two main fixing points. That's where I earthed mine with solid eye terminals.


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