Thousands without power after dust outage

About 4500 homes in Perth's northern suburbs were without power this morning after power lines were damaged.

Homes in the North Beach, Padbury and Mullaloo region lost power at about 4.30am after three lines went down in the area.

A Western Power spokeswoman said humid conditions and dust on the lines caused "arcing" on the lines.

One power line fell down and switches on two other poles were damaged.

The spokeswoman said crews restored power to some areas by about 6.30am.

Power had returned to most homes by 9am.