Hundreds of homes in Derbyshire were left without power after coal was piled against an electricity pole and set alight.
About 1,100 residents in Hatton were affected by the blackout in the early hours of the morning.
Power company E.On said 279 people will remain without electricity until the installation can be replaced.
A spokesman said it was unusual for someone to go to so much trouble to attack a pole.
He added: "When the pole is burnt down, we have to replace the pole as well as the transformer so it is going to be a long old job.
"It is an unusual one, to say the least, where people have gone out kitted up with coal to burn a pole."