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How to Split a Circuit Breaker to Prevent Circuit Overloads

Written by Edwin Jones / Fact checked by Andrew Wright

how to split a circuit breaker

Do you experience circuit breaker trips due to circuit overload? Do you have one circuit breaker for two different rooms? Do you know how to split a circuit breaker to prevent this problem in the future?

Circuit overloads are caused by plugging too many devices into one circuit. It mainly occurs when you have one circuit breaker for two or more rooms. To solve this issue, consider adding a new circuit breaker instead of upgrading your breaker amp capacity.

Continue reading this article to learn how to split a circuit line and prevent circuit overload.

Tools You Need


  • Insulated gloves for additional protection
  • Pliers for removing electrical panel slot covers, if any
  • Flathead screwdriver for disassembling the connected wire in your breaker
  • A circuit breaker with a rating of 15 or 20 amps—depending on the circuit you need to split

The circuit breaker amp size depends on the circuit you need to separate. I would usually recommend a 15-amp circuit breaker for lights and a 20-amp circuit breaker for outlets.

These are the tools you need to split a circuit if you have a double-tapped breaker panel. However, you will also need the following if you’re splitting a circuit from a junction box:

  • Wire stripper for stripping both ends of the wire
  • Wire connectors for securing your new wire connections
  • Extra wires with an appropriate gauge for splitting a circuit at a junction box

Step-By-Step Guide on How to Split Double-Tap Circuit Breaker?


Splitting a double-tap circuit breaker is straightforward—you only need these two steps.

Step 1: Disconnect One Line in your Double-tap Breaker

Check if you have any appliances or devices plugged in and running on the circuit you’re going to work on. Ensure they’re switched off and unplugged to prevent any possible damage. Once done, turn off your main breaker and then disassemble the panel cover.

Once you have access to your double-tap circuit breaker, start loosening the screw and pull out one line. Then you can tighten the screw with just one line left installed on that particular circuit breaker. Now, proceed with installing an additional circuit breaker.

Step 2: Install Additional Circuit Breaker and Connect the Extra Line

Install your additional circuit breaker in your extra slot or space in your breaker box. Loosen the screw, then connect the line that you just separated from your double-tap breaker. Once you’ve placed the wire, tighten the screw.

Before putting back the panel cover, remove the slot cover on the respective breaker slot if it still has one. Otherwise, just install the panel cover directly.

Turn on the main breaker switch and check if the circuit is working correctly. Furthermore, don’t forget to add a label to your new breaker. It is easy to split the circuit in your double-tap circuit breaker, especially if you have too many rooms on one breaker panel.

Step-By-Step Guide on How to Split a Circuit in Your Junction Box


Step 1: Find the Linked Wire in Your Junction Box

First, you need to find the junction box that connects two circuit branches into one breaker. To do that, first, switch off the main breaker. You then need to disconnect the line from the breaker that overloads.

Once you’ve done that, look for the junction box that connects the two circuit branches. This is typically placed in between them. Alternatively, you can look up electrical plans for your house if you have one. Inside that junction box, you should see a cable (with green, white, and black lines) that split into two other cables.

Now, to confirm that you’re looking at the correct electrical cable you need to split, have an assistant tug the black line from the panel side. You should see the entire cable in the junction move slightly as your assistant lightly pulls the corresponding wire.

Once you’re familiar with the cable that connects both circuit branches to the circuit breaker, remove one of the cables (with the corresponding color-coded lines) from the cable that leads to the circuit breaker.

Step 2: Install a New Line

Once you’ve completed the previous step, you need to wire a new electrical cable from the panel to the junction box. Ensure that you’re using a cable with three lines: green (ground), white (neutral), and black (hot).

Also, check that it matches that gauge you have in your previous connection. This is to ensure that the cable can handle your breaker’s amp capacity.

Step 3: Connect the Line

Using the wire stripper, strip both ends of the cable to reveal the three lines. You then need to strip both ends of each line (green, white, and black). Once done, connect the lines of the cable you’ve just installed to the lines you’ve removed from the original connection in step 1.

Don’t forget to use wire connectors for safety. Here’s a short article that can help you choose the top-rated wire connectors. I’ve used these in my previous electrical projects, so I can vouch for their quality.

Step 4: Install Additional Circuit Breaker

You can now install your breaker in your breaker panel. Using your flathead screwdriver, connect the ground (green) wire to the ground bar, the neutral (white) wire into the neutral bar, and the hot (black) wire to your newly installed breaker.

Make room for your new breaker on the panel. Remove the corresponding slot cover using your pliers. Once you’re done installing the new breaker, you can reinstall the breaker panel cover.

I also found this video by Family Handyman, which can help you further understand adding a new circuit to your breaker panel.

Note: Always remember to turn off your main breaker before proceeding with any electrical work. This way, you’re sure there’s no flowing power that could cause an accident. Furthermore, if you are not comfortable working with wiring and electrical cables, it is better to call a licensed electrician.

Additionally, this guide is only applicable for a breaker panel which has more space for a new circuit. If your current panel doesn’t have available space for a new breaker, I suggest upgrading your main panel first. Then, you can install a new breaker to have a split breaker panel.


Knowing how to split a circuit breaker can save you money under the right conditions. Splitting a double-tap breaker is straightforward as long as you have an empty slot in your panel.

If you have to tap a junction box to split a circuit, it may require more effort but is still worth it from the resources you save. Also, consider wire connectors I’ve used to help connect the new and old cables you’re splitting.

So, does this address your problem with overloads? I’ll be happy to read your thoughts in the comments below.

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