How do I change out a breaker in my main breaker box?


My main breaker box does not have a shutoff switch. Is it safe to install a new breaker onto the breaker bus with the breaker in the off position? Or is there a way to kill power to the breaker box somehow that I'm missing?

  8 answers
  • Cindy Cindy on Jun 13, 2020

    Hi Darren. No. Do not try to install a new breaker. It's not safe if it's live whether it's in the off position or not. It's still live behind the breaker. This is a job for a professional.

    • Darrin Darrin on Jun 13, 2020

      Thank you Cindy. I saw someone post that he did this and thought he was crazy so I had to ask. When I switched off the breakers at the main panel I used my no touch voltage tester to see if it was still live behind the breaker and sure enough it was so I stopped. I don't have any issues with installing a new breaker, I've done it before but at a different location and only after the power was completely off but I can't do that at this location as I can't kill all the power. I'm calling in the pros.

  • Cynthia H Cynthia H on Jun 13, 2020

    Please use a licensed electrician for this. Worth every penny. Good luck and stay safe!

  • William William on Jun 14, 2020

    Do you by any chance have two breaker boxes. Sometimes there's no room in the main breaker panel for anymore breakers so a sub-panel is installed that needs to be shut off at the main panel. If you only have one panel box there should be a main breaker to turn off power to the panel. Otherwise call an electrician

    • Darrin Darrin on Jun 14, 2020

      I do. My sub panel is upstairs. My main box is outside next to my meter. I need to add a breaker to my main box outside. There is a 100 amp breaker in this box which I thought was the main service interrupt breaker but when I turn this breaker (and all the breakers in the box) to off the hot bus bars are still hot. There are no other switches or breakers in this box to kill all power. I have called an electrician and he will be here tomorrow. Thanks for your reply.

  • Tom Stuart Tom Stuart on Jun 14, 2020

    A house should have a breaker panel on the inside of the house with main power box on the outside next to the electric meter.

    if you live in an apartment there may be a utility room which has the panels for all apartments. Check with your building manager to unlock the room so you can shut off your power.

    Use a non-contact current meter to be sure you don’t have a live

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    • Tom Stuart Tom Stuart on Jun 15, 2020

      Good decision. I hate to have to call a professional but realizing a project has gotten beyond your safety limits is important.

  • Redcatcec Redcatcec on Jun 14, 2020

    If you can't find the main cut off, you might try asking a neighbor where theirs is, they might have the same set-up as you and can advise you.

    Also is there a chance you could be looking at a sub panel rather than the main 1? Try looking around, it should be located near where the power comes into the house from the outside.

    You may need to call in a licensed electrician.

    • Darrin Darrin on Jun 14, 2020

      Thank you for the reply. I do have a sub panel, its located upstairs in my house. I'm working on the main panel outside on the side of my house next to my meter. It has no service interrupt breaker or switch that I can see. When I turn all breaker to off in the main panel the hot bus bars are still hot. I use a non contact voltage tester to verify. I have a electrician coming tomorrow.

  • Em Em on Jun 14, 2020

    Glad to hear you are getting an electrician. Electricity is nothing to fool with if you are not 110% sure of what you are doing.

    120 Volts Can Kill you. Ordinary, household, 120 volts AC electricity is dangerous and it can kill.

  • William William on Jun 14, 2020

    Glad your getting an electrician. Any chance the somehow the sub panel is powering the main panel. Have you tried cutting the breakers off in the sub panel?!

    • Darrin Darrin on Jun 14, 2020

      I haven’t. The 100 amp breaker in the main box is labeled sub panel so I think that breaker runs the sub panel.

  • Betsy Betsy on Jun 14, 2020

    Hi Darrin: Definitely a job for a professional, unless you have a huge insurance policy, and a death wish :) I would most certainly get someone in that knows what they're doing. Make sure they are bonded and licensed and if need be, they pull the permit. If you don't know what you are doing, you could burn your house down and your insurance won't pay you a cent :( Hate to burst any balloons you may have had on this subject. Check at your home improvement store, they may be able to recommend someone, or even check with the electric company. Good luck and stay safe.

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    • Betsy Betsy on Jun 15, 2020

      Oh, good. Believe it or not, I was worrying about you :) Better safe than sorry. Thanks for letting me know. I can sleep tonight :)