Foteck SSR's @*^^?&#! JUNK

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Yeah. Horse is dead. But at the risk of belaboring, here's a temp reading on a knockoff Berme 40a SSR running a 5500w element at 100%. It peaks at about 135 deg F. If your heat sink is cool to the touch, you have a magical heat sink.
 

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golfindia said:
Yeah. Horse is dead. But at the risk of belaboring, here's a temp reading on a knockoff Berme 40a SSR running a 5500w element at 100%. It peaks at about 135 deg F. If your heat sink is cool to the touch, you have a magical heat sink.
Click to expand...
you know those "berme knockoffs" aren't knockoffs right? They are made on the same assy line as the mgr and auberin SSRs.. A fan makes all the difference in cooling... This is why all CPU's use fans on the heatsinks..
 
golfindia said:
Yeah. Horse is dead. But at the risk of belaboring, here's a temp reading on a knockoff Berme 40a SSR running a 5500w element at 100%. It peaks at about 135 deg F. If your heat sink is cool to the touch, you have a magical heat sink.
Click to expand...

WOW, if that honking slab of aluminum is @ 130f "outside" your small box with 1 ssr on it, One can only think of how hot that SSR is inside your box. Only 1 thing could fix that.....a magical FAN.:mug:
 
Esmitee said:
When I get my replacement SSR's, I'm going to tear that Fotek apart, and I bet I'll find a much lower rated TRIAK? And I'm not a betting kind of guy!
Click to expand...
I went though endless Foteks and they were all fake and fried or never worked. I bought some Crydoms on Ebay for cheap. Still going after a year. That would be my suggestion
Heres a picture of one of the melted Foteks I cracked open. Maybe the numbers will mean something to you?

https://www.homebrewtalk.com/forum/threads/numbers-inside-a-melted-ssr-pic.592756/
 
golfindia said:
Yeah. Horse is dead. But at the risk of belaboring, here's a temp reading on a knockoff Berme 40a SSR running a 5500w element at 100%. It peaks at about 135 deg F. If your heat sink is cool to the touch, you have a magical heat sink.
Click to expand...
I do have what appears to be just about that same heat sink mounted on a rims+biab panel I made with a 40a ssr and an ssvr mounted to it and To be honest it gets much hotter than my my main control panel heat sinks because there is no fan to cool it. I actually havent decided if I'm going to replace it or not because I dont like how hot it gets compared to the cheaper heat sink and fan setups mounted inside my other two panels.
View media item 68523
 
JONNYROTTEN said:
I went though endless Foteks and they were all fake and fried or never worked. I bought some Crydoms on Ebay for cheap. Still going after a year. That would be my suggestion
Heres a picture of one of the melted Foteks I cracked open. Maybe the numbers will mean something to you?

https://www.homebrewtalk.com/forum/threads/numbers-inside-a-melted-ssr-pic.592756/
Click to expand...

Hey, when I tear that ssr apart, I will look for some kind of ID markings on it, like on the one you opened up.
 
I run a very large heat sink that sits right on top of my 50a panel. It get's pretty hot during the boil. It get's close to 100 degrees for sure. When I have both elements running it's over 110 degrees for sure. If you touch it you know it's hot. Those heat sinks may not be the best choice for a 60A panel but should be adequate depending on good surface contact and thermal paste. Especially with a fan to help cool.

After doing the research for my panel build. I would never buy a Fotek SSR even if the Pope himself was selling them. The net has thousands of stories about fakes coming from very reputable electronics supply chains. There are way to many SSRs out there that have zero reported fakes. They are only a dollar or two more.
 
LarMoeCur said:
I run a very large heat sink that sits right on top of my 50a panel. It get's pretty hot during the boil. It get's close to 100 degrees for sure. When I have both elements running it's over 110 degrees for sure. If you touch it you know it's hot. Those heat sinks may not be the best choice for a 60A panel but should be adequate depending on good surface contact and thermal paste. Especially with a fan to help cool.

After doing the research for my panel build. I would never buy a Fotek SSR even if the Pope himself was selling them. The net has thousands of stories about fakes coming from very reputable electronics supply chains. There are way to many SSRs out there that have zero reported fakes. They are only a dollar or two more.
Click to expand...
I would have to agree with this.. The only reason I still have a few foteks kicking around is I bought them for my first panel build or they came with pics I bought back then and they all still work fine.. I was lucky.
I now buy the berme (mager,mgr made) for $5 each with free shipping.
 
golfindia said:
Those cheap heat sinks don't get warm to the touch, because they don't conduct heat..... The fans are just Blowing warm air around inside of that box. Best of luck.
Click to expand...
Heatsinks get hot because they do an inadequate job of transferring heat to the air in the configuration in which they are used. The thermal conduction of the heatsink only affects how well heat gets from the component being cooled out to the fins, which is were most of the heat transfer to the air occurs. Even with low thermal conductivity, a heatsink would get hot if it didn't transfer heat well to the surrounding air.

golfindia said:
Physics. Mass dissipates heat. Weight one of those $2 Tee shaped heatsinks. I used some of them for a long time too. Until I switched to a real heat sink. My real heat sinks get hotter than hell. Because they are dissipating heat. But hey, whatever works. It's not like we're operating nuclear powerplants. It's just beer.
Click to expand...
Mass does not dissipate heat. Mass absorbs heat, analogous to how a capacitor absorbs electric charge. The purpose of a heatsink is not to absorb heat, but rather to conduct heat away from a source and transfer that heat to the surrounding air. The fact that your heatsink gets hot means that it is not transferring heat efficiently to the surrounding air. It has nothing to do with the mass of your heatsink. The cooler your heatsink, the better job it is doing of getting rid of the heat transferred to it by the heat source. A poor thermal interface reduces the amount of heat the gets transferred from the source to the heatsink, resulting in a hotter source.

Blowing air over a heatsink (forced convection) can easily increase the thermal dissipation by 10X or more, compared to natural convection. OP actually has a rather well designed forced convection cooling system (fan, separate air inlet and outlet, fan air stream aimed directly across heatsinks.) The heatsinks OP is using are more than adequate in that configuration.

Heat flow mathematics is just like electricity flow math. In fact thermal engineers use electrical circuit models to do calculations on heat flow and component temperatures. If you understand electric circuits, you can apply that knowledge to heat flow.

Brew on :mug:
 
doug293cz beat me to it, but yup, a lot of misinformation about heat sinks in here.

A heat sink, despite it's name, is not meant to absorb and hold all the heat from the object it's attached to. Not entirely. As said above it's meant to provide a heat path to get heat out of a part and into a cooling medium. Heat is not some static thing, it's energy. Imagine it like a facet pouring into a bucket. At some point the bucket is going to fill up and overflow, unless you're draining that bucket to something else at least as fast as it's being filled. Same with heat, you're dumping heat into the heat sink, but unless you're moving that heat to the surrounding air you will eventually heat soak the heat sink and then both it and the part will climb in temperature until something fails.

Placing a heat sink in still air is called natural convection. It works, just not amazingly. To be efficient you need a LOT of surface area on the cooling fins. That's why guys that choose not to use a fan use a very large heat sink with a lot of fins. As long as your surface area allows heat to flow out of the heat sink at least as fast as it's being put in by the load (SSR in this case), you'll be ok.

Again as mentioned above, forced convection (moving the air over the heat sink) is amazingly more efficient. Even a small amount of air flow makes an incredible difference. The more air flow you have the less surface area your heat sink needs with that air. To go back to my horrible bucket analogy, instead of just having a drain in the bucket we'd be pumping the water out. The larger the pump, the smaller the bucket can be to catch all that's coming out of the facet.

So to relate this to your SSR and heatsink choice. If your heat sink is getting hot, that means the SSR is hotter. And the hotter the SSR runs the shorter it's life will be. Knockoff or not, heat kills electronics. If you want your setup to last a long time go overkill with the heatsink and consider a fan. Every now and then you're going to get a junk SSR if you're buying ones known to be flaky, but the cooler you keep things the longer they should last.
 
augiedoggy said:
say that first sentence out loud ... Does that make any practical sense? The official rating of the device already has this buffer built in.

Again many fake fotek SSRs use components designed for only 10 amp regardless... A real 25amp rated device is rated to be used for up to 25amps that includes 23 amps... If it makes you feel better to use 40 amp equipment for 23 amps great but it isn't needed unless the products your using aren't properly designed.
The NEC 80% rule everyone here keeps misquoting if for devices that draw 100% sustained loads for over 3 hours continuous.

The truth is we are all discussing this without even knowing how the SSR was being cooled
Click to expand...

Yeah that first sentence was bad, sorry. I never said it made sense to me, that was just the way it was explained to me by the facilities manager who had an associates in EET. I'm a horticulturalist not a electrician. I guess the NEC 80% rule made sense for the lights being ran for 16-18 hours.
 
lump42 said:
Yeah that first sentence was bad, sorry. I never said it made sense to me, that was just the way it was explained to me by the facilities manager who had an associates in EET. I'm a horticulturalist not a electrician. I guess the NEC 80% rule made sense for the lights being ran for 16-18 hours.
Click to expand...
Yeah there's a lot of scenarios and stipulations in the rulebook. That and the rulebook is always changing.
 
My heatsink is setup on the side on the side of the box with the ribs facing up and down to form a draft. I can hold my hand 3 inches above the top of the heatsink and feel the hot air coming off it.

It gets piping hot at times. My last brew day I put the box near my front door and opened the door just a crack. Just the small draft from the door instantly cooled the heatsink from to hot to touch to luke warm. A small amount of movement goes a long way.
 
JONNYROTTEN said:
My heatsink is setup on the side on the side of the box with the ribs facing up and down to form a draft. I can hold my hand 3 inches above the top of the heatsink and feel the hot air coming off it.

It gets piping hot at times. My last brew day I put the box near my front door and opened the door just a crack. Just the small draft from the door instantly cooled the heatsink from to hot to touch to luke warm. A small amount of movement goes a long way.
Click to expand...
Yep. Placing the heatsink on the side of the box, as you have done, will improve natural convection significantly. I'm not sure who started the trend of putting heatsinks on top of enclosures, but people seem to follow that lead blindly. It's not optimal for natural convection, but it does work well enough in most instances.

Just for the record, I spent 36 years as an electronics packaging engineer (i.e. how to put components in modules, how to attach modules and other components to circuit boards, and how to put circuit boards and other things into enclosures.) One large sub-discipline in electronics packaging is thermal engineering (i.e. how to get rid of the heat generated by electronics.) Thermal engineering wasn't my specialty, but I worked closely with many thermal engineers, and learned quite a lot along the way. This doesn't make me any better than anyone else, but it does give me some credibility when discussing this topic.

Brew on :mug:
 
LarMoeCur said:
I run a very large heat sink that sits right on top of my 50a panel. It get's pretty hot during the boil. It get's close to 100 degrees for sure. When I have both elements running it's over 110 degrees for sure. If you touch it you know it's hot. Those heat sinks may not be the best choice for a 60A panel but should be adequate depending on good surface contact and thermal paste. Especially with a fan to help cool.

After doing the research for my panel build. I would never buy a Fotek SSR even if the Pope himself was selling them. The net has thousands of stories about fakes coming from very reputable electronics supply chains. There are way to many SSRs out there that have zero reported fakes. They are only a dollar or two more.
Click to expand...

Well, 1st of all, in the case of these brewing control panels we're talking about here, I don't think you size the heat sink(s) for the ssr's by the total amperage of the panel. You have to size the heat sink(s) to match the ssr's.

Say you have a 60 amp panel and you have (1) 60 amp ssr. Yes, you would need a rather large heat sink to dissipate the large amount of heat that 60 amp ssr is going to generate.

Now lets say you have a 60 amp panel and you have (6) 10 amp ssr's. You could have 6 small heat sinks because they would generate very little heat individually, or, have 1 very large heat sink if you combined them on a single heat sink. In this case, my guess is you would need even a larger heat sink than the size of a heat sink rated for a single 60 amp ssr. Doug may clear this up?

i agree with you on the Foteks, like I said before, I didn't purchase the ssr's separately , they came bundled with the Mypin controllers. :mug:
 
doug293cz said:
Heatsinks get hot because they do an inadequate job of transferring heat to the air in the configuration in which they are used. The thermal conduction of the heatsink only affects how well heat gets from the component being cooled out to the fins, which is were most of the heat transfer to the air occurs. Even with low thermal conductivity, a heatsink would get hot if it didn't transfer heat well to the surrounding air.


Mass does not dissipate heat. Mass absorbs heat, analogous to how a capacitor absorbs electric charge. The purpose of a heatsink is not to absorb heat, but rather to conduct heat away from a source and transfer that heat to the surrounding air. The fact that your heatsink gets hot means that it is not transferring heat efficiently to the surrounding air. It has nothing to do with the mass of your heatsink. The cooler your heatsink, the better job it is doing of getting rid of the heat transferred to it by the heat source. A poor thermal interface reduces the amount of heat the gets transferred from the source to the heatsink, resulting in a hotter source.

Blowing air over a heatsink (forced convection) can easily increase the thermal dissipation by 10X or more, compared to natural convection. OP actually has a rather well designed forced convection cooling system (fan, separate air inlet and outlet, fan air stream aimed directly across heatsinks.) The heatsinks OP is using are more than adequate in that configuration.

Heat flow mathematics is just like electricity flow math. In fact thermal engineers use electrical circuit models to do calculations on heat flow and component temperatures. If you understand electric circuits, you can apply that knowledge to heat flow.

Brew on :mug:
Click to expand...

Hey Doug, thank you for making this CRYSTAL CLEAR!:bravo:
 
I can’t help but jump in. Assuming a heat source is constant (and we do not know if we are all assessing the same thing, as different SSR’s under different current flows, duty frequency, voltages, etc. will produce different amounts of heat) then the heat sink’s job is to conduct that heat away from the SSR and convect, conduct, and radiate it it to the air around it. If the interface between the HS and the SSR conducts poorly, the HS will be cooler to the touch than if it conducts well. So that doesn’t mean it’s working well. If the HS conducts heat from the SSR well but doesn’t transfer it to the atmosphere well, it will be hot to the touch.

So unilaterally saying hot or cold to the touch is not a legit assessment of a HS’s performance. If you want to accurate determine performance, take temp readings from the SSR baseplate and the HS mount surface (should be close) then from the mount surface to the distal fins (should have a delta), then the ambient air.
 
BrunDog said:
I can’t help but jump in. Assuming a heat source is constant (and we do not know if we are all assessing the same thing, as different SSR’s under different current flows, duty frequency, voltages, etc. will produce different amounts of heat) then the heat sink’s job is to conduct that heat away from the SSR and convect, conduct, and radiate it it to the air around it. If the interface between the HS and the SSR conducts poorly, the HS will be cooler to the touch than if it conducts well. So that doesn’t mean it’s working well. If the HS conducts heat from the SSR well but doesn’t transfer it to the atmosphere well, it will be hot to the touch.

So unilaterally saying hot or cold to the touch is not a legit assessment of a HS’s performance. If you want to accurate determine performance, take temp readings from the SSR baseplate and the HS mount surface (should be close) then from the mount surface to the distal fins (should have a delta), then the ambient air.
Click to expand...
This is true but the surface would have to be really ueven for this to occur with thermal grease which has been used. I have bought about 8 of these cheap heat sinks off eBay now usually going with the cheapest source at the time and I have yet to see this. Not saying it's not possible but I just don't think it's likely either as if it were bent slightly screwing the SSR would likely have some effect on flattening against the ssr surface.

My current build for my 3bbl panel has 2 very large repurposed heat sinks from a 2000w uv lamp ballast. I'm planning on mounting them on the sides as I've read many times here that they will dissapate the heat to the air faster this way. I too think most people seem to care more about the cosmetic aspect when mounting on top. If I had the room to mount internal sinks in the fans path I wouldn't hesitate.
 
You raise a valid point. Note that thermal paste has a conductivity of around 10 W/mK while the heatsink itself is around 200. The thermal paste is there to fill the voids which exist in and between the mating surfaces of the SSR and the HS. Many people take the “more is more” approach to thermal paste, which actually reduces heat transfer efficiency. Depending on the paste, it may not flow well out along the surface and “self level”. So it is very possible for the transfer to be inefficient.

Also quality heatsinks have flat milled mount surfaces. The cheap ones are extruded, which mean their consistent contact with the SSR baseplate may not exist.
 
Sorry to bump a dead thread, but appears this would be the appropriate place for this.

Unfortunately I wasn't aware of the fake Fotek issues and already purchased one with heat sink off eBay. Should I just go ahead and buy a different SSR, or use the possibly fake Fotek until failure. Is it even safe to do so? Seems to be a fire hazard? Fwiw I'll be mounting the heatsink external to the controller junction box.
 
Last edited:
No comment on any of the fake things, but I suggest buy Crydom SSRs. I do believe in the quality of american made products. I understand that sometimes the same can be had for less, but buying twice really pizzes me off, sorry China.

I built my electric system in 2009. I have two dual SSRs, Crydoms. I've used it many ( :) ) times. Still going strong.
 
LittlejohnBrew said:
Sorry to bump a dead thread, but appears this would be the appropriate place for this.

Unfortunately I wasn't aware of the fake Fotek issues and already purchased one with heat sink off eBay. Should I just go ahead and buy a different SSR, or use the possibly fake Fotek until failure. Is it even safe to do so? Seems to be a fire hazard? Fwiw I'll be mounting the heatsink external to the controller junction box.
Click to expand...
I wouldn't use them in a system you intend to walk away from while in operation. Many people have used them and had failures, but I don't recall any reports of actual fires. The device can scorch and partially melt - accompanied by acrid smells - but damage is usually limited to the device itself. If one does fail on you, and you don't have a spare, your brew day is pretty much over.

Brew on :mug:
 
Well about a week after my last post , I did get my new SSR's and new heat sinks, even though I really didn't need new heat sinks. I got a good deal on the SSR's, that included the larger heat sinks and thermal paste and I thought it would be even better with the larger heat sinks. So I retrofitted my panel. The SSR's are 40 AMP MGR's. Hopefully I will not have any problems? Time will tell

20180308_212843.jpg
The heat sinks are Din mountable, The old ones were Din mount, and were mounted as such. If I mounted these new ones on the Din rail, the fins would be the opposite direction for good air flow. So I had to drill and countersink a hole in the center on the mounting area for the SSR. This way, the fins are in the best orientation for best cooling air flow.
20180308_213718.jpg
Thermal paste applied
20180308_213750.jpg
I also put a little thermal paste over the countersink screw head for total coverage.
20180308_220405.jpg
New SSR's and heat sinks installed and wired
20180319_170028.jpg
Full view of SSR's, heat sinks and the cooling system
 
mabrungard said:
That's a bit much on the thermal grease. It's only supposed to fill the micro and macro gaps between the two surfaces. Hopefully you tightened the SSR down to the sink.

I haven't heard of fires, only cases where the magic smoke leaves the component and your boil abruptly ends.
Click to expand...
I know you don't need much, It's really not as much as it looks in the picture, I got 2 little tubes with my purchase, and I didn't even use 1/2 of 1 tube. I tightened the SSR's down pretty good, and had a little squeeze out.

When my ssr blew, it made a popping sound, followed by massive amounts of smoke, that stunk to high heaven. No fire. Actually , the whole panel remained ON until I hit the E stop. When I opened the panel up, No damage at all, except the melted Fotec ssr. The only thing was a film of smoke on an adjacent switch and a few wires going to that switch. I wiped the smoke film off with a damp paper towel. You can't even tell anything went wrong.
 
You still need some paste, just not much of it. Think 'half a grain of rice' amounts.
 

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