Paul Ridings, 39, of South Benfleet, Essex was investigating a fault with an energy meter when he inadvertently disturbed a loose connection and exposed a strand of wire leading to an electrical explosion.
His clothes caught fire and he sustained burns to his face, neck, chest, arms and hands.
He received emergency treatment and spent 19 days in the Specialist Burns Unit at Broomfield Hospital. Since the incident he has undergone numerous skin grafts and operations to remove scar tissue.
Basildon Crown Court heard Ridings had been contracted to work for Lafarge Cement UK and an investigation by the Health and Safety Executive (HSE) found the firm failed to ensure electrical systems were maintained in such a way as to protect workers.
The company admitted breaching sections 2(1) and 3(1) of the Health and Safety at Work etc. Act 1974. It was fined £130,000 and ordered to pay costs of £29,742.
HSE inspector, David King, said: “Every year approximately 20 people die from electrical shocks or burns following incidents at work. Mr Ridings could easily have been killed in this incident.
“It’s clear that in this case the overall arrangements for maintaining electrical assets were inadequate and the health and safety of both staff and contractors were put at risk.”