Heat sink setup question

Well, I finally got approval from SWMBO to go full electric. I ordered the plugs for my kettles last night. I was looking at the SSRs and heat sinks on the auber website, and that is 40 bucks for a heat sink and relay! Ebay has options for a whole lot cheaper! I am looking at this setup on ebay, which would save me over 30 bucks on the setup. Now, if I mount this SSr and heat sink inside the control panel with the temp controlled fan in there, would that be sufficient? Or will I be burning up SSRs that way? Here is the link

http://www.ebay.com/itm/Solid-State...ultDomain_0&hash=item2ec2a50585#ht_2157wt_945

This relay setup with the fan will still save me about twenty bucks.

It seems like that would work OK. I have used that exact SSR (though I got it off Amazon) and just screwed it into a metal electrical junction box as a heatsink.

how many amps are you going to be running through your ssr? I'm building a 110 volt around 15 amps system but I will be using a 40amp ssr with a heat sink so I anticipate that my ssr will not get very hot ever. but if you will be putting the ssr through it's paces quite roughly it will produce quite a bit of heat. I don't think you should need a fan unless your enclosure is really small with poor ventilation.

Also make sure to get some thermal grease to put between your ssr and heat sink. it can help quite a bit.

Standard 5500 watt element, so 23-24 amps through the ssr. I am using a sealed enclosure like the one kal used.

You can scrap a heatsink out of all sorts of thinks. Old tuner / amp, old pc old tv.... just to name a few. keep an eye on ebay for ssr A couple months ago I picked up four 30a ssr for $20 w/ free shipping.

It's not the question of getting a heat sink, it's the mounting configuration. I think I have decided to go with a case fan pulling fresh air across the heat sink, fully enclosed in my box. Chime in if that's a bad idea.

I have a 40a SSR and heat sink on each of my elements and mounted the heat sinks outside the panel and the SSRs inside. And the heat sinks get very hot to the touch even being on the outside. The way my panel is positioned I wouldn't use a fan with the heat sinks inside as a spill could potentially get inside the panel through the hole for the fan. Your setup may be different and it not be a problem. But I'd use a nice strong fan. The heat generation is a lot more than I would have thought.

If you decide to go outside with the heat sinks, I cut out a side of the panel and put in a thin layer of aluminum flashing over the hole and used silicone to seal it up. Then I put the SSR on one side with thermal paste and the heat sink on the other with thermal paste. It works like a charm.

The pic shows five heat sinks. The outside ones are the elements, the next in are the pumps, the center one is a 25a SSR/heat sink for the alarm. I probably could have not used a heat sink for the alarm ssr as it is only on for six seconds every so often.

I have never seen anyone use heat sinks for the pumps and alarms. Any particular reason?

I ended up buying a heat sink and ssr on ebay just now for 8 bucks. I am going to mount it on the side of the backplate inside the enclosure with a fan blowing right on it, or pulling air from right next to it.

The SSRs generate heat whenever the circuit is closed. So even for a pump it generates some heat and I didn't want any excess heat hanging around in the panel causing problems just in case.

And I had them laying around and figured what the heck, might as well use them.

Here's a simple controller using the same heatsink, similar SSR, no fan.
http://www.theobtuseangle.com/PictureViewer/PictureViewer.aspx?pictureSetId=7

milesvdustin said:

I have never seen anyone use heat sinks for the pumps and alarms. Any particular reason?

I ended up buying a heat sink and ssr on ebay just now for 8 bucks. I am going to mount it on the side of the backplate inside the enclosure with a fan blowing right on it, or pulling air from right next to it.

Click to expand...

I would put a heat sink on any ssr you are using, it's not going to hurt and they are cheap and easy to mount on DIN rail. For the fan, think about what you do to cool off hot food before you take a bite. You blow on it, you don't suck air across it. Make sure you have a vent to let the air move out too. I can't tell how many relays you're using, but with a 92mm(3.5"ish) fan I have had no issues keeping 6 relays (4 of them high power) happy in my enclosure.

I spoke to a rep at Open Source Control Systems about mounting the 2 SSR/Heatsinks inside a 16x16x8 control panel without a fan and no venting to run my PIDs. They said that it should be okay in this application. I'm going to give it a go and see how it does. As a back up I'm laying out my panel so I can easily add a fan to draw air in if need be.

Here's what I'm picking up: http://www.oscsys.com/store/product/1001674

I will have one contactor and one ssr inside my enclosure. One PID and one timer. The rest switches and wiring. So I guess one fan forcing air in and then a vent on the other side and I will be good. Thank you all for the tips and showing me some other setups.

ironmountainbrew said:

I spoke to a rep at Open Source Control Systems about mounting the 2 SSR/Heatsinks inside a 16x16x8 control panel without a fan and no venting to run my PIDs.

Click to expand...

Other than the control panels I see on here, I have yet to find one in the wild unrelated to brewing with antlers poking out of it. lol