Flames erupted and smoke billowed in Maidenhead last night.
Firefighters were called out to a manhole on fire at the junction with Ray Mead Road and Ray Park Road, near to the Thames Hotel, at 7.30pm.
The crew from Green Watch waited for the electricity company to turn up and swich off the power.
Many homes lost power.
Firefighter Paul Strudwicke said: "It was burning quite well.
"They said the electricity would be back on at 5am."
Southern Electric confirmed the fire was put out after engineers cut the power supply, leaving 80 homes in Ray Mead Road without electricity.
But as engineers began work to repair the blown fuse, another fault was found with an underground cable in Grosvenor Drive and electricity had to be cut to further 230 homes.
A spokeswoman for Southern Electric said: "We apologise for any inconvenience caused to any of our customers affected by the power cut."
Firefighters left the scene at 10.40pm and power was restored to the majority of houses by 11.30am today.
Watch a video filmed by a guest at the hotel.
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