>"you should never intentionally rely on a safety feature to cut you out - they exist as a backup in case you screw up" I've had to use core drills with inline

>"you should never intentionally rely on a safety feature to cut you out - they exist as a backup in case you screw up" I've had to use core drills with inline (inbuilt) RCDs while hanging off rope. Those things draw ludicrous current, and are water lubricated with open thermal ventilation for the motor. It's a given that they trip out. Unfortunately, as soon as a safety feature is regarded as reliable, it's incorporated into standard operating procedures. See Erlang for a well executed version of this idea!