How to Use a Clamp Meter

  • 2 hours
  • Intermediate
  • 50-100
What You'll Need
Clamp meter
Electrical conductor
AC Line separator

A clamp meter is a tool for measuring current on a wire. In contrast to a multi-meter, the clamp meter does not need to be connected to the circuit in order to read current. It gets rid of the unnecessary procedure of breaking the circuit to measure current. The clamp on the device is simply placed around a live wire. This allows one to measure the current on a wire without interrupting the operation of the electrical appliance. A clamp meter uses digital technology to bring instantaneous readings. Here is simple guide to operating a clamp meter.

Step 1 - Buy a Clamp Meter

Go to the electrical supply shop or home improvement store and purchase a clamp meter. Some clamp meters also provide features that can measure voltage, while other clamp meters only measure current.

Step 2 - Choose an Electrical Conductor to Test

The clamp can easily measure the current on a load without the need to disconnect the electrical conductor from the circuit. To get a reading, the electrical wire should be connected to an electrical appliance that is running or operating. As a safety precaution, it is best to remove the wire from the power source first before getting a reading.

Step 3 - Choose the Appropriate Function and Range

Set the rotary selector on the clamp meter to the correct function and range. Measuring current that is higher than that specified in the range can damage the device. In addition, the electrical conductor should be running on voltage lower than 600V. The device cannot read the current on conductors running on very high voltage. If you're not sure about the range, choose a high range and decrease it as needed.

Step 4 - Clamp the Conductor

Push the trigger on the device to open the jaw. Clamp the device around the conductor and close it. If the electrical conductor is not yet connected to a power source, connect it. The clamp should give a reading in seconds.

Step 5 - Use an AC Line Separator

When measuring AC current, the device may give a false reading. Hot and neutral current cancel each other out, which causes the device to display nothing on the LCD screen. To correct the problem, connect the AC line separator to the power source and attach the electrical conductor to the AC line separator. Clamp the meter to the AC line separator to measure the current.

Step 6 - Measure Voltage

Set the clamp meter to the voltage symbol “V” to read the voltage on the conductor. Plug the probes to the meter as well. Connect the black probe to the COM jack and the red probe to the V/O jack. Select the correct range and make sure not to measure voltages that are above 600V. Touch the tips of the probes to the electric conductor to get a voltage reading. Read the voltage on the LCD screen.

A clamp meter will save you time during an electrical repair work, will help you get more efficient with your wiring projects, and will protect you from electrical-related accidents.