Advice for Heat Sinks on 50 Amp Panel

[canmorebrewguy]

Hello All,
I am looking for advice on heat sinks for my panel. It will be a 50 amp BCS unit in a 20"X20"X8" Stainless enclosure. Do people prefer the individual heat sinks that fit the SSR or do you purchase a larger unit and tap all of the sir's to one larger unit?
Cheers,
CBG

 

[JONNYROTTEN]

I only run one SSR with a large 8"x3" heat sink and it still gets mighty hot. Ebay is a great source for large reclaimed heat sinks. Get the biggest one possible. I would mount one on each side of the panel if your hanging it one the wall with the ribs running up and down. They get so hot it forms a draft sorta and running them up and down will help pull away the heat. I use one like this. One of these for each heat sink would work. Keeping a small fan blowing on the panel will help.
http://www.ebay.com/itm/Large-Recla...319127?hash=item281dd6f757:g:jdgAAOxy79JSUtSo

 

[Dfitz]

My 50A panel uses a 6x16x2"h heat sink. It barely gets warm on a 12k/49ish amp load.

I usual buy my large heat sinks from http://www.heatsinkusa.com/

I think it was this one. I'd order a length to fit the width of your panel minus 2".
http://www.heatsinkusa.com/8-000-wide-extruded-aluminum-heatsink/

 

[BrunDog]

Some suppliers like electric brew supply make heatsinks pre-tapped for 4 SSR's. Quality SSR's, especially zero cross, mounted with appropriate thermal grease will perform well and stay cool passively.

That said, @JONNYROTTEN brings up a good point regarding vertical mounting. I have never mentioned it here because it might spark controversy. Kal's design and those which follow suit mount the heat sink on the top of the enclosure. But a heatsink mounted with the fins running lengthwise vertically will perform better in terms of convective cooling.

 

[Dfitz]

I failed to mention my panel supports two separate systems. While only one operates at a time I had to mount a total of 6 SSR/SSVRs so I needed the larger space to occomodate the components

 

[doug293cz]

I only run one SSR with a large 8"x3" heat sink and it still gets mighty hot. Ebay is a great source for large reclaimed heat sinks. Get the biggest one possible. I would mount one on each side of the panel if your hanging it one the wall with the ribs running up and down. They get so hot it forms a draft sorta and running them up and down will help pull away the heat. I use one like this. One of these for each heat sink would work. Keeping a small fan blowing on the panel will help.
http://www.ebay.com/itm/Large-Recla...319127?hash=item281dd6f757:g:jdgAAOxy79JSUtSo

Some suppliers like electric brew supply make heatsinks pre-tapped for 4 SSR's. Quality SSR's, especially zero cross, mounted with appropriate thermal grease will perform well and stay cool passively.

That said, @JONNYROTTEN brings up a good point regarding vertical mounting. I have never mentioned it here because it might spark controversy. Kal's design and those which follow suit mount the heat sink on the top of the enclosure. But a heatsink mounted with the fins running lengthwise vertically will perform better in terms of convective cooling.

I've also mentioned the benefits of mounting heatsinks on the sides of the enclosures a couple of times around here. There seems to be little understanding among a lot of folks about the physics of how heatsinks actually work. They are not really heat "sinks" (they don't suck up heat) but rather thermal transfer devices, and you need to maximize the transfer efficiency. Fortunately for most, the less efficient horizontal mounting seems to be good enough.

Brew on

 

[sensortech]

I built a 50A panel and just use the small ones. I have a 4" 12v fan on each side of the enclosure always moving air through. can run everything at once with no problems.

 

[stevehaun]

I have a 50 amp system. I use crydom SSRs and appropriately matched crydom heat sinks mounted vertically. No fans. During my last batch, I actually put a thermocouple on the heatsink next to the SSR whilst brewing a batch and maximum temp was 130F. I think the size of the electrical enclosure also plays a role - my enclosure is 20" X 16" X 8". You should be even better off with a larger enclosure.

 

[doug293cz]

I have a 50 amp system. I use crydom SSRs and appropriately matched crydom heat sinks mounted vertically. No fans. During my last batch, I actually put a thermocouple on the heatsink next to the SSR whilst brewing a batch and maximum temp was 130F. I think the size of the electrical enclosure also plays a role - my enclosure is 20" X 16" X 8". You should be even better off with a larger enclosure.

I agree that your relatively large, metal enclosure is what allows it to work for you. Probably wouldn't work for a plastic enclosure, or an enclosure with significantly less surface area.

Brew on

 

[augiedoggy]

I've also mentioned the benefits of mounting heatsinks on the sides of the enclosures a couple of times around here. There seems to be little understanding among a lot of folks about the physics of how heatsinks actually work. They are not really heat "sinks" (they don't suck up heat) but rather thermal transfer devices, and you need to maximize the transfer efficiency. Fortunately for most, the less efficient horizontal mounting seems to be good enough.

Brew on

For some the heat sink on the top looks cooler and that Trump's function it seems..

 

[Dfitz]

For some the heat sink on the top looks cooler and that Trump's function it seems..

Mounting on the side of the enclosure on the outside might look just as cool. I had no room on the inside for a heat sink so on the outside it was. In any event, it functions so...

 

[doug293cz]

Mounting on the side of the enclosure on the outside might look just as cool. I had no room on the inside for a heat sink so on the outside it was. In any event, it functions so...

Outside is better for cooling anyway. Heatsinks inside the enclosure usually need fans and vents in the enclosure to get adequate cooling.

Brew on