By Mike Sokol
Welcome to my J.A.M. (Just Ask Mike) Session, a weekly column where I answer your basic electrical questions. If you’re a newbie who’s never plugged in a shore power cord (or ask – what’s a shore power cord?), or wonder why your daughter’s hair dryer keeps tripping the circuit breaker, this column is for you. Send your questions to Mike Sokol at mike (at) noshockzone.org with the subject line – JAM.
Since I’ve been promoting the use of digital meters over the last few months, now I’m getting questions on how to use them. Well, I’m here to help.
First of all, never poke the meter probes into an outlet before you’ve set the meter to the appropriate scale.
In most cases the 600-volt AC scale is the best one to use since you could be measuring anything between 0 and 240+ volts. And as I’ve noted many times in my advanced classes, it really doesn’t matter if the black and red probes are reversed when measuring AC voltage. That’s because in the U.S. the voltage polarity reverses itself 120 times every second. The AC scale on the meter accounts for this rapid polarity swapping, so you just need to plug the meter probes into the appropriate slots on the outlets to get an accurate reading.
Here’s a basic tutorial video on how to use a $20 Southwire multimeter to measure AC voltage. Watch the short video HERE or click on the picture.
And if you learn better from reading about a topic rather than watching a video, then stay tuned next week for a basic written tutorial on meter usage.
OK, everyone. Remember that electricity is a useful and powerful force, so we all need to pay attention to safety precautions while using it.
Let’s play safe out there….
Mike Sokol is an electrical and professional sound expert with 50+ years in the industry. His excellent book RV Electrical Safety is available at Amazon.com. For more info on Mike’s qualifications as an electrical expert, click here.
For information on how to support RVelectricity and No~Shock~Zone articles, seminars and videos, please click the I Like Mike Campaign.