More than 14,000 properties in Perth and surrounding areas were left without electricity this morning as summer rain caused a number of power poles to catch fire.

Key points: Pole-top fires are caused when built-up dust interacts with misty rain

Pole-top fires are caused when built-up dust interacts with misty rain The combination creates tracks that allow the electrical current to arc

The combination creates tracks that allow the electrical current to arc Power has been cut to houses across Perth's north, south and east

From about 4:00am, fire services were inundated with reports of power poles burning — from Joondalup in Perth's north to Singleton, south of the city.

The pole-top fires were sparked by light rain interacting with dust build-up on insulators following recent dry weather.

Western Power spokeswoman Jillian Reid said the dust build-up, when combined with misty rainfall, could allow paths or "tracks" to be created across the power pole which allowed the current to arc or spark.

While this usually tripped a safety device that cut the power, the current could sometimes continue to flow, causing metal fittings and bolts to become extremely hot, which could then ignite parts of the pole.

"Rather than misty rain, if there had been a downpour it would have washed the powerlines and insulators," Ms Reid said.

Repair crews drain water from an insulator that caught fire in Karrinyup. ( ABC News: James Carmody )

Dozens of repair crews dispatched

Ms Reid said dozens of Western Power technicians had been dispatched this morning to restore power, but in the meantime people should avoid downed lines, and report any faults.

"We do have crews that have been dispatched and are working to repair the faults as quickly as possible and they will be working, as a number-one priority, to remove any hazards on the network and then to get people reconnected," she said.

"If customers see any downed power lines they should stay eight metres away and call Western Power immediately on 13 13 51."

At 7:00am, thousands of properties across the Perth metropolitan area remained without power. ( Supplied: Western Power )

Among the worst affected areas in the north this morning were:

Joondalup

Joondalup Ocean Reef

Ocean Reef Duncraig

Duncraig Scarborough

Scarborough Trigg

Trigg Malaga

Malaga Ellenbrook.

In the east there were outages in:

Bassendean

Bassendean South Guilford

South Guilford Midland

Midland Kelmscott

Kelmscott Seville Grove

Seville Grove Armadale

In the city's south there were more than 2,000 outages from a pole fire in Munster, which affected:

Munster

Munster Coogee

Coogee Beeliar

Beeliar Wattleup

Wattleup Henderson

Henderson Spearwood

South of Perth, pole fires in Singleton left more than 4,000 properties in the Mandurah area without electricity.

Compensation available for lengthy blackouts

Western Power asset manager Sean McGoldrick apologised for any inconvenience caused.

He said the utility hoped to have most customers reconnected before lunchtime and the remaining few back online before 6:00pm today.

"If there is an extended outage beyond 12 hours there is a compensation scheme available through our website," he said.

"That will not compensate completely for the inconvenience but at least it will be something, but I hope we will have the power back on before then."

Ms Reid said Western Power spent about $400 million a year on maintenance of its poles and wires. The utility has previously said it was not practicable to wash all of the more than 800,000 poles in its network.

It was also working to place power lines underground where possible, and silicon was applied to tens of thousands of insulators each year to prevent dust build-up, with a focus on applying these techniques in bushfire-risk areas.

Western Power crews were mobilised across Perth to restore power. ( ABC News: James Carmody )

Department of Fire and Emergency Services metropolitan operations Superintendent Stuart Wade said crew safety was the first priority when dealing with pole fires.

"We will always call on the energy provider to isolate the affected poles before we will apply any form of suppression or water to the poles," Superintendent Wade said.

"The message to the public is that if there is a fire on one of the energy poles then to treat them with respect because we regard the wires as being live until they've been determined isolated by the energy provider before we'll go in there and put it out."