How to Easily Measure Low Amperages in AC

To make a 10-wrap rig, you simply take one strand of wire and wrap it to make 10 individual strands in a loop. You can put an ammeter clamp anywhere on it and get a more precise amperage measurement than your meter allows by using a little bit of math.

When you measure the amps on a rig with 10 wraps of a single wire, the amps of the wire itself are multiplied by 10. Thus, when you apply your ammeter clamp to the 10 wire rig, all you have to do is take the measurement and move the decimal point to the left to determine the amperage of a single wire. The 10-wrap rig also isolates the wire and makes you less likely to pick up amperage from other nearby wires.

For example, you could check the amperage on a condenser fan motor and yield 1.1 amps. When you use a 10-wrap rig, you will get a measurement like 11.8 for the wire with 10 loops. You move the decimal point over and get an amperage reading of 1.18 for a single wire. That’s a lot closer to 1.2 than 1.1, and that extra precision can be quite helpful.

We use #14 wire with male and female spade connectors in this video.

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