I was using my isolated high-voltage supply earlier and I had this strange issue where I would feel tingling upon touching some other part of the circuit and the earthed metal case of the supply simultaneously. When I connected the probes of my battery-powered handheld digital multimeter between the highest voltage output and the metal case with the supply turned on I measured just over 100 volts DC. I was able to finally narrow down the issue to my bench top multimeter (Fluke 8010A). Removing the bench top multimeter dropped the voltage down to under half a volt. I can measure around 100v DC between the metal enclosure and the isolated DC output of the supply whenever the bench top meter is connected to the circuit regardless of whether the meter is powered on or not. I can actually turn off the outlet and as long as the meter's ground pin on the plug is connected to earth I will get this voltage. I can even measure the same voltage when a single probe from the bench top meter is connected to the 0v output on my supply. It seems like there's leakage current between the meter's inputs and mains earth.
I measured the resistance between ground on the plug and the negative input of the multimeter and it was greater than 20M ohms (my handheld DMM cannot measure above 20M ohms). Any thoughts on this? I can probably get access to a PAT tester on Monday if that would help but I really did not expect the multimeter to fail this way.
I measured the resistance between ground on the plug and the negative input of the multimeter and it was greater than 20M ohms (my handheld DMM cannot measure above 20M ohms). Any thoughts on this? I can probably get access to a PAT tester on Monday if that would help but I really did not expect the multimeter to fail this way.
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