What Is A Multimeter And How To Use It

What Is A Multimeter?

Not sure why your outlet isn’t working? Sounds like you might need a multimeter! Not sure what a multimeter is? It’s a handy little tool used to help investigate problems with outlets. If you’ve never used a multimeter, keep on reading to find out how to perform your own test.

What A Multimeter Will Tell You…

  • If power is reaching the outlet
  • Whether or not the outlet is grounded correctly
  • If the wiring inside of the outlet is reversed

How to test an outlet using a multimeter

  • Learn the basics of outlet testing safety

    You’ll be performing your tests on a live outlet so you’ll watch to make sure your holding both meter probes in the same hand. This will prevent the current from flowing through your body. DO NOT let the metal part of the probes touch each other. This may create a dangerous short circuit.

  • Know the parts of the outlet

    Your outlet has 3 slots – one for hot, one for neutral, and one for ground. The rounded half circle is ground, the long slot (left) is neutral and the short slot (right) is hot.

  • Adjust your multimeter as needed

    Set your multimeter to measure voltage. Then set the alternating current (AC) function (which may be shown as having a wavy line, whereas the DC function will have a solid and dashed line).

  • Connect the leads

    Push the short, thick connector of the BLACK lead into the connector labeled “COM” (which may have a “-“ next to it). Plug the RED connector with a “+” or horseshoe (omega) symbol.

  • Measure voltage

    Again, using the SAME hand, insert a probe into each vertical slot on your outlet. Put the red lead into the smaller slot and the black lead into the larger one. If your outlet is working correctly, you should receive a reading of 110-120 volts. If you don’t get a reading, you’ll need to check the wiring on the outlet.

  • Figure out if the outlet is grounded

    Remove the black lead and put it into the half-circle slot of the outlet. Your reading should remain the same. If it changes, the outlet is grounded wrong. Or the wiring may be reversed…

  • To see if the wiring is reversed

    Put the red lead into the left slot and the black lead into the ground (half-circle slot). If you get a reading this way, your wiring is reversed. While this problem doesn’t affect simple appliances like tableside lamps, it can create problems for larger appliances that you might want to plug into the outlet.

If your outlet is wiring incorrectly or you’re unsure of what to do, don’t attempt to fix the problem yourself! Electrical problems are not DIY projects. Avoid the risk of electrocution by contacting an experienced electrician. Call A-Abel Electric, today!

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