Buzzing Switchboard

A switchboard that buzzes, hums or crackles is telling you something is wrong. While a faint hum can be harmless, a persistent or loud buzz often signals loose connections or an overloaded circuit that can overheat. Sydney Power Group (SPG) responds 24/7 across Greater Sydney.

A buzzing board is frequently the stage before more obvious danger signs. If it progresses to arcing or a burnt smell, treat it as urgent — see sparking switchboard and burning smell from switchboard.

What the Buzz Is Telling You

A steady mechanical hum can come from a transformer or contactor and may be normal. But a buzzing that's new, getting louder, or accompanied by warmth or a faint smell usually means a loose terminal, a failing breaker, or an overloaded circuit — where electricity is straining against a poor connection.

Because the causes overlap with more serious faults, it's worth having a buzz checked before it becomes a burning smell from switchboard.

Tracing the Source of the Noise

Our electricians safely isolate the board, then inspect terminals, breakers and busbars for looseness, heat damage and signs of arcing. We measure loads to see whether a circuit is overdrawn, and tighten, repair or replace whatever's causing the noise.

As a Level 2 ASP we also check the consumer mains termination at the board, since a loose supply connection can hum too.

Quiet It Down Safely

A buzzing board rarely fixes itself and can quietly get worse. Call SPG on 0466 125 125 now, or book emergency help. If the board is old, ask about a switchboard upgrade.

See more on the emergency electrician hub.