[de_]

I checked with tech support at Sparkfun.com since they sell a lot of this stuff.

The 100v volts will only provide a mildly discomforting shock due to the very very small current available. Not remotely life threatening.

The rule says 24v relative to the robot common buss. It is possible to design inverters whose outputs are totally isolated from the inputs (think isolation transformers). So if you use a voltage meter between the common buss and any output HV wire on the inverter, it reads 0 volts. Lab power supplies should be an example where the outputs are completely isolated from any of the input power lines. Else its not usable in a situation that needs differential power.

Unfortunately according to Sparkfun, its 12v inverter input common wire input is connected to one of the output wires so if you measure the robot common to the other HV line you should see 100v AC.

Oh well. Back to robots