And that was a power supply exploding. Exploding may be a strong word, it was just one resistor that vaporised, but it managed to go through three different surge protectors and blow the main breaker somehow.
In related news, I am very awake now.
oh, this should be tagged #Engineering
oh, the power supply also has a fuse which didn't burn up.
So we are considering getting a UPS to test out any high power electronics on before plugging them into the mains.
Does anyone have any suggestions on how to most effectively test high power things like this without plugging them into the same mains power that all of our other electronics are using?