Electrical – Why did sparks fly when testing outlet frequency

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I'm using a multimeter (Mastercraft 052-0052-2) and I decided to see if the frequency of an outlet would read 60hz. I switched my multimeter to the FREQ setting and plugged the RED test lead into the NEUTRAL of the outlet. Upon doing this, a loud bang occurred with a huge spark. Yet the outlet still works and the breaker did not trip. Could somebody explain to me what may of occurred?

The multimeter works fine and no fuses were blown. The BLACK test lead was just resting on the carpet floor. (It probably didn't touch the carpet though, since it the metal probe sits 2cm above the carpet.)

Best Answer

If you drew sparks with only a single probe, it suggests that you accidentally shorted across neutral to hot somewhere on the outlet.

Studying and understanding the manual and the limits of the meter would likely help you to avoid such mishaps. (Or even worse such as fire or electrocution.) Any kind of measurement of mains power should use considerable caution.

Unless the meter is rated for measuring mains frequency, it would be better to avoid measuring high voltages like that. For practical purposes, the frequency of the utility power is the least likely to change or be worthy of measurement. Unless you were getting power from a portable generator or some "off-grid" source.