I have a bunch of Fotek SSRs, rated 385V / 40A.

Well, that's what it says on the label.

Perhaps I have been hanging around with Americans too long, but I
recently bought a bullet-casting melter. I wasn't happy with the
temperature controller, so I modified it with a PID controller and
SSR.

https://photos.app.goo.gl/mq4NFtVtiSsVHFSk9

(A variant of that 1/32 DIN controller has a built-in 5A SSR, which
might be an easier modification, but I used the relay / ssr driver
version: https://www.ebay.co.uk/itm/193179699038 )

I measured the cold resistance of the element at 111ohms, so that's
nominally 2A, or 3A if we allow for the actual peak mains voltage.

So I figured that the 40A SSR should be fine. Imagine my surprise when
it failed short-circuit almost immediately.

It was potted up, and when I pulled it apart the actual driver chip
fell apart, so no way to be sure what the actual rated current was
now. The last one of these I took apart had a 10A driver, so that is
what I have been mentally rating them at. Perhaps I was wrong.
Possibly it's a fake 10A driver in a fake 40A SSR?

If you are wondering why a resident of the UK wants a bullet mould, I
have been making tiny glass-bottomed peter tankards:
https://photos.app.goo.gl/RHmiUKG1BtCT5qW16

-- 
atp
"A motorcycle is a bicycle with a pandemonium attachment and is
designed for the especial use of mechanical geniuses, daredevils and
lunatics."
— George Fitch, Atlanta Constitution Newspaper, 1912


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