how did you protect your lab setup?

I would say, the best thing is avoiding mains entirely for the smaller power rating stuff.

I use a floating DC Lab supply to run a pure sine wave inverter (300W) as my synthetic mains supply for testing of smaller items. Fault currents are very limited thanks to the inverter's small power rating and blowing fuses is not likely in case of a hard fault - the inverter usually simply cycles (another benefit).

For higher current mains stuff, I made an isolation transformer out of back to back toroidal transformers. The upside is this breaks the earth connection which means that accidental contact between device and earth won't result in a shock, but also means some modern safety features (e.g. RCDs) won't save you. The jury is usually split on this sort of thing.

I also use a variac with my supplies to bring them up gently if necessary, feeding all power through a Tektronix PA1000 Power Analyzer just to see if anything is wrong as the voltage is coming up.

I would suggest soldering in insulated wire for probe points, maybe screwed down into a terminal block for safer probing. Then you can use a DMM or scope probe and touch the screws or metal parts in a more convenient location. Still prefer screwing the probes down into the terminal block and not changing connections while powered on to avoid surprise smoke events.

Use a remote power switch - I have a radio controlled power switch I can remotely turn on and off. Where nasty results are expected, I'll have my camera observe while I apply power from a distance.

Make sure the item is sitting on a nonconducting surface ...

- Gough

I would say, the best thing is avoiding mains entirely for the smaller power rating stuff.

I use a floating DC Lab supply to run a pure sine wave inverter (300W) as my synthetic mains supply for testing of smaller items. Fault currents are very limited thanks to the inverter's small power rating and blowing fuses is not likely in case of a hard fault - the inverter usually simply cycles (another benefit).

For higher current mains stuff, I made an isolation transformer out of back to back toroidal transformers. The upside is this breaks the earth connection which means that accidental contact between device and earth won't result in a shock, but also means some modern safety features (e.g. RCDs) won't save you. The jury is usually split on this sort of thing.

I also use a variac with my supplies to bring them up gently if necessary, feeding all power through a Tektronix PA1000 Power Analyzer just to see if anything is wrong as the voltage is coming up.

I would suggest soldering in insulated wire for probe points, maybe screwed down into a terminal block for safer probing. Then you can use a DMM or scope probe and touch the screws or metal parts in a more convenient location. Still prefer screwing the probes down into the terminal block and not changing connections while powered on to avoid surprise smoke events.

Use a remote power switch - I have a radio controlled power switch I can remotely turn on and off. Where nasty results are expected, I'll have my camera observe while I apply power from a distance.

Make sure the item is sitting on a nonconducting surface ...

- Gough