Testing a fuse

[brian john]

Originally Posted by btharmy

I respectfully have to disagree. When testing from line to line, the tester IS the load. When checking a fuse in, lets say an energized 200a. 480v disconnect, if one was to put his tester in series with a bad fuse (top to bottom) the meter and its leads become the only current path for that particular phase of the load supplied by the disco. It BECOMES the fuse, previously blown (possibly due to a dead short down stream from the disco) thus passing who knows how much fault current thru the meter. Am I on track with my reasoning? If not, fill me in. I have always held to this thinking because I have never been convinced otherwise.

Use simple logic and you would see how wrong this is, based on this logic using a tester to measure voltage to ground would be a DEAD SHORT, whole lot worse than putting a few hundred amps through the tester.

Assuming you are using the right tool for the job.