How Do You Test a 240-Volt Circuit?

Using a multimeter, insert one of the probes from the multimeter into one of the parallel slots in the 240-volt outlet and insert the other probe into the other parallel slot to test if the outlet is indeed carrying 240 volts. If the voltage does not add up to 240 volts, check the slots individually to see which one is carrying less voltage.

A multimeter will measure the amount of volts running through a circuit. It is important to make sure that the probes are properly connected to the multimeter to ensure there will not be an electric shock.

  1. Set up the multimeter
  2. Plug the two probes into the correct slots in the multimeter. Make sure that the probes are completely plugged in and not damaged in any way. Set up the multimeter to measure alternating current in the 240-volt range.

  3. Connect the multimeter to the wall outlet
  4. Wall outlets with 240 volts will have two parallel slots and one circular ground wire slot. Insert the two probes from the multimeter into the two parallel slots of the wall outlet.

  5. Read the multimeter to test the circuit
  6. If the multimeter measures somewhere close to 240 volts, the circuit is working properly. If there are significantly less than 240 volts, one or both of the slots is not carrying enough voltage. Each slot should carry 120 volts, so measure them individually to see which one is carrying less.