How to Change a Circuit Breaker

A circuit breaker is connected to an electrical circuit and is designed to stop the power flow though the circuit in the event there is an excessive amperage draw on said circuit. Occasionally, however, these breakers go bad, and you will need to know how to change a circuit breaker. It is highly recommended that you hire a licensed, competent, and insured electrician to perform this task, as electricity can be deadly. However, the steps are outlined below, as some of you readers are simply perusing this article for educational value, and as some may simply get bad advice elsewhere. Follow the steps to learn how to replace a circuit breaker.

Steps

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    Find the main circuit breaker box. Some homes may have 1 large main breaker box as well as smaller branch breaker boxes.
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    Locate the defective breaker. A tripped breaker is halfway between the on and off position.
    • Before assuming a circuit breaker needs to be replaced, try resetting the breaker by turning off all lights and unplugging all devices on that circuit. Then turn the back to the on position.
    • Some breakers must be turned all the way off before they can be turned back on.
    • Test the circuit breaker by turning on the breaker, and then add the devices 1 at a time. If the light or device becomes operable, then a voltage tester is not needed.
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    Use a voltage tester to see if power is going out through the wire attached to the breaker.
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    Turn off the branch breaker boxes, followed by the main power.
    • This should be the large flip switch located above or below all the other smaller ones. It should also be labeled "main" or something similar. The main breaker typically has the largest amperage rating of all the breakers in the panel.
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    Turn off the individual breakers.
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    Inspect the exterior of the panel. If there is evidence of rust, charring, discoloration, moisture, or other contamination, DO NOT proceed, and call an electrician immediately.
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    Beware of certain types of panels, specifically those bearing one of the following names: Federal Pacific Electric, Federal Pioneer, Zinsco, Kearney, GTE Sylvania, or Stab-lok. The safety of these panels is highly debated. Research the issue, and contact an experienced electrician for advise. Decide what to do based upon the information you find.
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    Use protective equipment. Wear insulated lineman's gloves and use insulated lineman's tools. Wear rubber-soled shoes and safety glasses, and stand on a rubber mat.
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    Be sure the area around you is safe. If there is water or another liquid present, do not proceed. Call a licensed electrician immediately. Also, be sure that there is plenty of clearance above, below, to the sides of, and in front of the panel.
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    Remove the screws holding the face plate (called a "dead front") with a Philips screwdriver. Use the left hand rule when opening the panel to prevent injury in the event of an arc flash.
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    Read the label on the main power switch to determine what kind of circuit breaker box you own.
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    Inspect (without touching anything) the interior of the panel. Look for signs of rust, moisture intrusion, pest intrusion, loose wires, melting, discoloration, charring, heat marking, multiple wires under one screw, aluminum wiring, wiring with damaged insulation, knob and tube wiring, strange modifications, debris, and multiple colored wires connected to each other. If ANY of these conditions are found, or if another type of strange thing is found, do not proceed. Call a licensed, competent, and insured electrician.
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    Loosen the screws that hold the wires found on the defective breaker.
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    Remove the breaker from the panel.
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    Discard the old circuit breaker.
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    Replace the old circuit breaker with the new one. The replacement breaker must have the same amperage and be the same type (unless using "classified" breakers) as the previous breaker. Snap the circuit breaker back into the same place as the old on the panel.
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    Place the wires in the new circuit breaker as they were in the old one.
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    Tighten the screws. Do not over tighten, but do not leave too loose either.
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    Replace the circuit panel's faceplate. If any of the original screws were lost, replace them with FLAT-ENDED MACHINE SCREWS. Using pointed wood screws may damage wiring inside the panel.
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    Turn on the main power, followed by the individual breakers.

Tips

  • You may need someone to hold a flashlight while you change out a circuit breaker. Many breaker boxes are located in dark areas such as basements and closets.
  • If the circuit breaker you are replacing is a GFCI (Ground Fault Circuit Interrupter) or AFCI (Arc Fault Circuit Interrupter) breaker, as sometimes used for outdoor, bedroom, garage, kitchen or bathroom circuits, be sure that you replace it with another one of the same type.

Warnings

  • NEVER touch the lugs adjacent to the main breaker and/or connected to the Service Entry Conductors. These remain live, even if the power is cut to the rest of the buss assembly.
  • If you cannot find the main power cut off switch, do not attempt to remove a circuit breaker or work on the circuit panel. Contact an electrician.
  • Do not replace a circuit breaker with one of larger amperage. This may cause a dangerous wiring overload.
  • If the new breaker does not remain closed and/or behaves similarly to the original breaker, shut off the power and contact a licensed, competent, and insured electrician.
  • DO NOT attempt to replace the main breaker yourself. Call a licensed, competent, and insured electrician to handle this situation.
  • DO NOT attempt to access the meter box, underground wiring/overhead cable, or any equipment owned and/or maintained by your power company. Call your power company if any of their equipment needs service.
  • NEVER work alone. Have someone observe, so that they can summon help should an incident occur.
  • If at ANY point you feel uncomfortable, unsafe, or unsure as to how to proceed, STOP. Call a licensed, competent, insured electrician. It is better to spend a little extra money for professional repairs than to risk death, serious injury, and/or extensive property damage. Remember these phrases-"When in doubt, subcontract it out!" and "Just don't know? Time to call a pro!"

Things You'll Need

  • Voltage sniffer
  • Multimeter
  • Lineman's Gloves
  • A Rubber Mat
  • Insulated Lineman's Tools
  • Rubber-Soled Shoes
  • Safety Glasses
  • An Observer
  • Replacement Circuit Breaker
  • Flashlight
  • Common Sense

Article Info

Categories: Electrical Maintenance