[eddie_ce]

As Beardyman pointed out in post #3 correct specification seems to be key.

I used to produce a small series of boards for emergency service control rooms and always used 1) components from reputable manufacturers and 2) a large safety margin regarding operating voltage vs component rating.

The only failures I had was when the apprentice decided polarity didn't matter, somehow one of these boards slipped through quality control and failed with spectacular results.