Four fire engines and around 25 firefighters were called to a fire at an internal substation on Talgarth Road in Hammersmith.
Two compressors on the ground floor of the building were destroyed by fire. There were no reports of any injuries.
A resident in a nearby building made the first call to 999 after smelling burning and seeing smoke coming from the roof of the building.
The Brigade was called at 0831 and the fire was under control by 1020. Fire crews from Hammersmith, Kensington, Chiswick and Chelsea fire stations attended the scene.
The Brigade’s Fire Investigators believe the fire was accidental and caused by a faulty compressor.