SSR burnout

[Guinjasp]

Hi wondering if anyone has had any problem with the Fostek SSR. Yesterday one of them burst into flames and luckily I was able to shut down the power and put out the flames.
Now the replacement and investigation as to what the root cause was. Any help would be greater appreciated

 

[Broken Crow]

At first glance, I'm thinking you have one of the fake Fosteks. You could take a look here; Fotek SSR's are not THAT bad... or just do a search for pics of the genuine ones for comparison. I've bought both real and fakes from Amazon, Aliexpress and ebay.... it's a crapshoot.

 

[doug293cz]

We get more posts about failed Fotek SSRs than all other brands combined. I routinely recommend against using them.

The hole blown in the top center of the SSR indicates this was most likely a failure of the internal TRIAC switch device, or it's internal connections. One of the problems noted with Foteks is that they use TRIACs that are rated for lower currents than the SSR is rated for.

There is no indication of heat damage to the AC wires or connections, just soot on the surface of the insulation. If you clean off the soot, and don't see any indication of heat damage to the insulation, then you don't have to replace the wires when replacing the SSR. Make sure you have clean metal on the wire connection lugs before reconnecting.

Brew on

 

[mabrungard]

We get more posts about failed Fotek SSRs than all other brands combined. I routinely recommend against using them.

I strongly agree! Stay away from Fotek. There is little way for the typical user to know if you're dealing with fakes or the real thing and the real thing isn't that great to begin with. I prefer Opto22 SSR's since they are very robust and their construction makes them unappealing for fakers to manufacture them.

 

[passedpawn]

Crydom.

 

[Guinjasp]

Thanks gents. Going to replace them all now.

 

[Guinjasp]

It could have burned my brewery down amazon stand behind these and weed out these imposters.

 

[passedpawn]

It could have burned my brewery down amazon stand behind these and weed out these imposters.

I'm not saying you (?), but most people just buy the cheapest one. Guess how that usually ends.

 

[doug293cz]

I'm not saying you (?), but most people just buy the cheapest one. Guess how that usually ends.

Sadly, this is true. Seems like half the folks that want to get into electric brewing just want the cheapest, minimalist system they can cobble together, without regard to safety features or durability. Your brewery controller is something you should only have to buy once.

Brew on

 

[jseyfert3]

It could have burned my brewery down amazon stand behind these and weed out these imposters.

Hmm. Perhaps try an electronic supplier like Digikey or Mouser? Well not impossible to get fakes I’d imagine the chances would be much lower than buying off Amazon.

 

[dtashmore547]

how is the heat sinking on the device? the triacs do generate quite a bit of heat, this will eventually degrade the device and cause it to fail. I mounted mine on a heatsink with a small fan to cool the SSR, just a cheap 30A device from aliexpress and it is running 4 years so far.

 

[Guinjasp]

Hi Dtashmore yes these are mounted on a heat sink and we have a small fan installed. Just puzzling. I wrote an email to Fostek asking for an explanation and will share their response if I hear back.

 

[RufusBrewer]

I admit I am a cheap SOB. But when it comes to my brewing, I tend to over build.

1) I value my time, I like to build something one time, repair and replace zero times.
2) It is a protection against a brew day getting interrupted or put and out canceled do to equipment failure

When it comes to semiconductors, buy and install over rated. When it comes to cooling, buy overrated heatsink. Adding a fan will not hurt.

Saving a few bucks today might result in tears down the road.

 

[duncan.brown]

That looks like a fake as there's no LED where the LED should be. Even then, Fostek are crappy. Take a look at

https://www.mouser.com/ProductDetail/Crydom/MCST2450ES?qs=oJ2OMJxL/i%2Bbr/EDZAOleA==

 

[Guinjasp]

Yes I am looking at Crydom Opto22 and Carlo Gavazzi. Done with Amazon crap that could burn my brewery down

 

[RufusBrewer]

That looks like a fake as there's no LED where the LED should be. Even then, Fostek are crappy. Take a look at

https://www.mouser.com/ProductDetail/Crydom/MCST2450ES?qs=oJ2OMJxL/i%2Bbr/EDZAOleA==

Am I reading that right? $117 for a SSR. Seems awfully steep.

Auber has a 40 amp relay for $16.45. Add a Heatsink for $20.00. I have never heard of the Auber private label SSR suffering quality issues.

 

[jseyfert3]

Am I reading that right? $117 for a SSR. Seems awfully steep.

Auber has a 40 amp relay for $16.45. Add a Heatsink for $20.00. I have never heard of the Auber private label SSR suffering quality issues.

With a minimum quantity of 10 to boot!

 

[duncan.brown]

$117 for a SSR. Seems awfully steep.

There are also good SSRs in quantity 1 if you browse around the site. That was the first one I found with a quick search, and it’s actually out of stock. Mouser has a nice interface that you can use to narrow down the specs.

I think it’s better to buy a reputable brand from Mouser than some fake junk that will catch fire. I wouldn’t trust Amazon, eBay, or Ali Express for anything that has more than a few volts DC going through it. I’ve been metaphorically burned enough times with chips from Ali Express that turned out to be junk. I don’t want to be physically burned!

 

[passedpawn]

Am I reading that right? $117 for a SSR. Seems awfully steep.

Auber has a 40 amp relay for $16.45. Add a Heatsink for $20.00. I have never heard of the Auber private label SSR suffering quality issues.

I've had all sorts of issues with quality from Auber. Don't kid yourself. Internally, their PIDs look like they were assembled by inmates somewhere.

That SSR linked above has a soft start feature that I don't think has any utility with a resistive element like we use in brewing. Here's an assortment of 30A Crydom (now, Sensata) SSRs at Digikey. They are all in the $40 range. Difference in these is their control input voltage range.
.
https://www.digikey.com/short/fz7j738v
Looking at the picture in the original post, it does look like an internal failure of the SSR. HOWEVER, half of SSR failures are at the connector, where a loose connection (e.g., bad crimp) = high resistance = heat = charcoal.

 

[Guinjasp]

Thanks Passedpawn. Will look these over for sure. Fotek Taiwan did respond asking for more information. Will let you know their response. I also reached out to the local distributor of Fotek for replacement pricing and insight. Perhaps they make a good quality product but are the victims of Chinese knockoff fraud which in all fairness is beyond their control.

 

[RufusBrewer]

Looking at the photo in the OP. Was the SSR mounted on heatsink? Hard to say for sure one way or the other.

If his new SSR is not properly installed, it will eventually fail as well. Invest in a heatsink, an oversized heat sink because you can never have to much cooling.

 

[Guinjasp]

Hi RufusBrewer yes they were all installed on a heat sink and there is a cooling fan also. I did read something about an epoxy that you should put between the relay and heatsink which I will probably do also.

 

[RufusBrewer]

Heat sink grease, not epoxy. There are also pads you can buy that are supposed to be superior to heat sink grease.

 

[oakbarn]

Crydom! I have had those cheap Amazon one fry themselves. I only use Crydom now as they are quality. I had a fire in my Brewery (unrelated to the Brewery {caused by a lawn mower}) and I don't ever want a fire again. You can sometimes find them less on ebay (Open box). I am thinking about mounting all my SSRs outside of my Brewery in a large Metal Box I got for free (Old Police Radio Reapeater Watherproof box.)

 

[MaxStout]

Heat sink grease, not epoxy. There are also pads you can buy that are supposed to be superior to heat sink grease.

Sil-Pads. They compress nicely between the device and sink and make good thermal contact.

 

[doug293cz]

Sil-Pads. They compress nicely between the device and sink and make good thermal contact.

When using pads, thinner is better (heat conductivity), as long as the pad compensates for any topography and/or lack of flatness of the mating surfaces.

Brew on

 

[passedpawn]

When using pads, thinner is better (heat conductivity), as long as the pad compensates for any topography and/or lack of flatness of the mating surfaces.

Brew on

Those materials are "phase change" which means they should become soft and conform to the surfaceswhen they get hot. I used to use them behind white LED boards and aluminum heat sinks.

But yea, thinner the better. I prefer just buttering a tiny bit of thermal grease. I use the stuff that they sell for between PC processors and the cooling block.

[edit] well, that one above might not be phase change material, but that's what I'd recommend. For example, this thermal material is actually sold by Crydom for use with their SSRs. just the right size, too

https://www.digikey.com/en/products/detail/sensata-crydom/HSP-7/5699205

 

[bruce_the_loon]

Anyone have experience with Kudom brand SSRs? Been looking around at our local suppliers and this is one that appears regularly amidst others.

For example, 40A 240V zero crossing - KSI240D40-L

 

[erikhild59]

We use Carlo Gavazzi on high end industrial builds at work. They're quality

 

[doug293cz]

Anyone have experience with Kudom brand SSRs? Been looking around at our local suppliers and this is one that appears regularly amidst others.

For example, 40A 240V zero crossing - KSI240D40-L

I would be leery of any brand that names itself to sound like another, well known brand (Crydom.)

Brew on

 

[oakbarn]

Anyone have experience with Kudom brand SSRs? Been looking around at our local suppliers and this is one that appears regularly amidst others.

For example, 40A 240V zero crossing - KSI240D40-L

Too Cheap to be good. I would not skimp here!

 

[Guinjasp]

So we decided to go back to Fotek as the footprint allows to bolt in the relay right into the heat sink. We discussed and purchased directly from a local Fotek distributor. Thought I would share the picture of old vs new. Lesson learned buyer beware when you buy off Amazon. You can see the difference in the two

 

[RufusBrewer]

Be weary of Fauxtek SSR.