[chbot] Matthias Wandel, and his amazing exploding SSR

Volker Kuhlmann list0570 at paradise.net.nz
Thu Aug 23 01:58:31 BST 2018


On Thu 23 Aug 2018 06:33:39 NZST +1200, Mark Atherton wrote:

> https://www.youtube.com/watch?v=FV9t1GFVbhU
> 
> What happens when you try and control a 22A electric water heater
> (presumably 120+120V in Canada) using a cheap 25A solid state relay.

Oops, thanks for posting that. I had similar plans, although with a bit
more protection. I have 2 100A versions here... but got them from
Aliexpress, so they must be good, right...? US$18/2.

Digikey has Omron G3NA series for around US$100+, and they require a
massive heat sink.

The bipolar load switching creates a significant voltage drop. Another
list member reported that the SSR got only lukewarm without heat sink
when operated at 10A for the 40A version. Does anyone else have
experience with this, and with which SSR model?

The guy who took one apart is wrong on his electrical safety assessment
though, there ain't 4mm clearance on that PCB...

25-40W power loss, big heat sink, 20mA permanent leakage (that's more
than an old wirewound transformer), me thinks a mechanical relay might
be better...

Volker

-- 
Volker Kuhlmann
http://volker.top.geek.nz/	Please do not CC list postings to me.



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