Why Is My EV Charger Making a Buzzing or Humming Noise?

Hearing a buzzing or humming sound from your EV charger can be unsettling. While some noise is normal, certain sounds may point to electrical issues that need attention. Let’s break down why your EV charger is making a buzzing or humming noise, when it’s safe, and when you should call a professional.

Is Buzzing or Humming Normal in an EV Charger?

Yes — a faint humming sound is normal for many EV chargers. That noise usually comes from:

• Transformers inside the charger that convert power.

• Cooling fans running during higher loads.

• Relays clicking on and off as charging starts or stops.

If the noise is soft and consistent, it’s usually not a problem.

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When Buzzing or Humming Is a Warning Sign

A loud or irregular buzzing may point to an electrical issue:

1. Loose Electrical Connections

Loose wires at the breaker, outlet, or inside the charger can create vibration and audible buzzing. This also generates heat, which can become a fire hazard.

2. Overloaded Circuit

If your charger is sharing a circuit with other appliances, it may draw too much current. Overloaded circuits can cause breakers to buzz or hum before tripping.

3. Defective Charger Components

Faulty relays, capacitors, or transformers inside the charger may produce unusual sounds. This is more common with older or lower-quality chargers.

4. Breaker or Panel Issues

Sometimes the noise isn’t from the charger at all — it’s from the electrical panel. A buzzing breaker usually means it’s failing and should be replaced.

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Troubleshooting Steps

1. Listen closely to locate the sound – Is it coming from the charger, the plug, or the breaker panel?

2. Check for heat – If the buzzing part feels hot, unplug immediately and call an electrician.

3. Inspect for loose plugs or connections – A snug, solid fit should be silent.

4. Reset the breaker – Sometimes a weak breaker causes humming until reset, but frequent humming means it needs replacement.

5. Test another outlet or charger – If possible, confirm whether the noise is unique to your unit.

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When to Call a Professional

• If the noise is loud or has recently gotten worse.

• If buzzing comes from the breaker panel.

• If you notice any burning smells, flickering lights, or tripping breakers.

These are signs of a serious electrical issue that should not be ignored.

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Final Thoughts

A soft hum from your EV charger is usually harmless, but loud buzzing often means something’s wrong with your electrical connections, breaker, or the charger itself. Because EV chargers run on high power for hours at a time, it’s best to get unusual noises checked by a licensed electrician before the problem gets worse.

👉 If you need help with EV charger installation in Dallas, Plano or the surrounding area, contact us today to schedule service or installation.