Four fire engines and around 25 firefighters were called to a fire at a warehouse on Jeffreys Road in Enfield.
An electrical switch room was destroyed by the fire. There were no reports of any injuries.
The Brigade was called at 1537 and the fire was under control by 1650. Fire crews from Enfield, Edmonton and Tottenham fire stations were at the scene.
Fire investigators believe the fire was caused by an electrical fault.