What you may be noticing
- The breaker trips partway through an overnight charge, often after an hour or more.
- Charging stops right away when the car is plugged in, with a fault light on the charger.
- The outlet, plug or charger cord feels warm or looks discolored.
- Trips started after adding the charger to an existing dryer or welder outlet.
- Charging works at a lower amperage setting but trips at full speed.
Common possible causes
Undersized circuit for a continuous load
EV charging runs at a steady draw for hours. Current electrical code treats it as a continuous load, so the circuit and breaker have to be sized with extra margin above the charger's setting. A charger set too high for its circuit will trip it.
Loose terminations
A loose wire at the breaker, outlet or charger terminal heats up under long, heavy loads. Heat can trip the breaker, damage the outlet and in worse cases cause a fire.
GFCI interaction
Many chargers have their own ground fault protection. When the circuit also has a GFCI breaker, the two can conflict and trip. Some setups require GFCI protection, so the fix depends on the charger and the installation.
Worn or light-duty outlet
Plug-in chargers on a 240-volt outlet put real strain on the receptacle. Outlets not built for repeated heavy use can wear, loosen and overheat.
Shared or overloaded panel
If the charger was squeezed onto a busy panel or the home's service is near its limit, the breaker or main may trip when charging overlaps with the AC, range and dryer.
Safe checks you can make
- Check the charger's app or display for a fault code and note it.
- Try lowering the charge rate in the vehicle or charger settings and see whether trips stop.
- Note when trips happen: right away, after an hour, or only when other big appliances are running.
- Feel the outside of the plug and cord after charging stops, without touching the outlet contacts. Warmth is a warning sign.
What not to do
- Don't replace the breaker with a larger one to stop the trips.
- Don't use an adapter or extension cord to reach a different outlet.
- Don't keep charging on an outlet that has discolored, melted or smells hot.
- Don't open the charger, outlet box or panel to check connections.
Can you sort this out yourself?
If the vehicle or charger is set to draw more than the circuit can carry, lowering that setting to match the circuit is a reasonable step and may stop the trips. Making sure the car's software and the charger's firmware are current sometimes clears fault behavior too. But if the plug or outlet runs warm, the breaker trips at reduced settings, or you aren't sure how big the circuit really is, stop there and have an electrician check it.
When professional help is appropriate
- Trips continue after lowering the charge rate.
- The outlet, plug or breaker feels hot or shows discoloration.
- The charger was installed on an existing outlet not meant for it.
- You're unsure whether the circuit was sized for continuous charging.
- The main breaker trips, not just the charger breaker.
What an electrician typically checks
An electrician will check the circuit size against the charger setting and the continuous-load rule, inspect and torque the terminations at the breaker and outlet, and look at whether GFCI protection and the charger's own protection are working together. A worn outlet may be replaced with a heavy-duty one, or the charger may be hardwired instead.
If the panel or service is the bottleneck, options include a load management device, a lower charge setting, or an upgrade. See EV charger installation and the EV charger electrical requirements guide for what a solid setup looks like, or garage outlet planning if the space needs more circuits too.
Keeping it from coming back
Have the charger installed on a circuit sized for continuous use, with the charger set to match. Use a heavy-duty outlet or hardwire the unit, and have connections checked if anything ever feels warm.
