How to Troubleshoot Arcing in your Main Electrical Panel

Electrical arcing in your main panel can be very dangerous and lead to fires or electrocution. Here is how to troubleshoot and fix arcing in your main electrical panel.

Signs of Arcing in the Main Panel

There are a few signs that may indicate arcing is occurring inside your main electrical panel:

You hear crackling, sizzling or buzzing noises coming from the panel. This is often the sound of electricity arcing.
You smell a burning or ozone odor coming from the general vicinity of the panel. Arcing can generate a lot of heat and smell.
You see signs of overheating like discolored or burned breakers, melted wires or black scorch marks inside the panel.
Lights are flickering or dimming throughout the house when large appliances turn on. This can indicate a loose connection.
Breakers are tripping frequently for no apparent reason. Arcing leads to short circuits.
You have frequent electrical shocks when touching appliances or outlets. Arcing can energize the metal panel enclosure.

If you notice any of these signs, it likely indicates arcing may be occurring and repairs are needed.

Turn Off the Power

Before doing any troubleshooting inside the electrical panel, turn off the main breaker or switch that controls all the power to the panel. Make sure all the circuit breakers are completely off. Use a non-contact voltage tester to confirm power is off before working inside the panel.

Inspect the Main Service Wires

Problems with the main service wires coming into the house can cause arcing. Look for the following:

Corrosion or damage on the service entrance wires or lugs.
Loose connections at the main breaker or bus bars. Wiggle wires to check for looseness.
Signs of overheating like melted plastic or insulation.
Broken or cracked wire insulation exposing bare conductors.

Any damaged, corroded or loose service wires must be repaired by an electrician.

Check the Breakers

Inspect each circuit breaker in the panel for problems. Look for:

Corrosion or overheating damage on the breaker body or contacts.
Cracks or damage to the breaker housing.
Breakers that are warm or hot to the touch. This indicates high resistance.
Loose breaker connections at the bus bars.
Breakers that have these problems should be replaced. Tighten any loose breaker connections.

Inspect the Bus Bars

Bus bars distribute power throughout the electrical panel. Check that:

Bus bars are completely intact and not cracked or broken.
No corrosion or overheating damage is present on the bus bars.
All screws and connections to the bus bars are tight.
No arcing scorch marks are visible on bus bars.

Check Neutral and Grounding Connections

Loose neutrals or ground wires can lead to arcing. Make sure:

The neutral bus bar is securely bonded to the metal panel enclosure.
The grounding wire is properly connected and tight.
All neutral wires have tight connections to the neutral bus.
Neutral wires are separated from ground wires.

Inspect Wire Connections

Arcing often occurs due to loose wire connections. Check that:

All circuit wire connections to breakers are tight.
There are no loose wire nuts or connections.
Lug terminals have no exposed copper visible.
Wires are making good contact with terminals.

Repair or Replace Defective Components

Any damaged, corroded or defective breakers, bus bars or wires you identified during inspection should be repaired or replaced. This may require having an electrician make repairs if you are unsure. Only replace breakers with identical models.

Clean the Panel Box

Vacuum out all dust. Carefully wipe down the panel interior with a dry rag. Remove any dirt, spider webs, insect nests or debris. This helps reduce the chances for further arcing or failures.

Thoroughly troubleshooting and inspecting your main electrical panel can help identify and remedy any arcing issues. This prevents potentially hazardous conditions that could put your home and safety at risk. If the panel arcing damage is beyond your skill level to repair, hire a licensed electrician.