Reminder: How to use a clamp ammeter….

Position of the conductor inside of the jaws is important! Or is it?

I just received this photo from my Facebook page. It’s a screen shot of an electrician with his clamp meter jaws pinching the wire like tweezers rather than surrounding it. So is he using his meter correctly?

It depends on what he’s measuring…

All modern digital clamp meters can measure AC current with the clamp jaws, and some can also measure DC current from your 12-volt battery system. To measure amperes of current the jaws have to completely surround the wire(s) being measured.

But it’s also a voltmeter!

At first glance it looks like this electrician is improperly trying to measure amperes of current flowing in this wire. However, instead of current he could be measuring AC volts in another part of the circuit using meter probes inserted in the bottom on the meter. If so he may simply be using the clamp jaws to hold the meter in place for viewing the numbers. And that works just fine.

Test one wire at a time when measuring current!

However, conductor position within the clamp jaws while measuring current is very important. Here’s a video I did a while back on how to properly split out the conductors for taking AC current measurements with a clamp meter.

More on this later…

I’ll do a more complete video on all the various ways to use a clamp multi-meter later, including the Non-Contact Voltage function and 3-phase rotation measurements available on some meters.

Let’s play safe out there - Mike