Firefighters were called to a fire at a electrical substation in the Cunningham Place and Aberdeen Place area in Maida Vale.
Three metres of high-voltage cabling connected to the substation was destroyed by fire.
Station Commander Paul Meyrick was at the scene, he said: "There was light smoke in the vicinity of the substation fire so residents were advised to keep windows and doors shut."
The Brigade’s Control Officers took the first of 16 calls to the fire at 1411 and mobilised crews from Paddington and Harrow to the scene. The incident was under control by 1746.
The cause of the fire is under investigation.