Jonathan Crosby, an employee of UK Power Networks, died instantly after being hit by 8,000 volts of electricity while working on overhead power lines in Diss, Norfolk.
The company, which owns and maintains electricity cables in the south and east of England, pleaded guilty to the charges relating to the incident in November 2007.
Norwich Crown Court heard that staff at UK Power Networks – formerly EDF Energy – had not received adequate training.
The Health and Safety Executive (HSE), which brought the successful prosecution, said its investigation had found that vital fuses supplying the transformer Crosby was working on had not been removed to cut the electricity supply.
HSE inspector Toni Drury said: “A family man has lost his life in tragic circumstances which could have been avoided if essential safety measures had been put in place by UK Power Networks.
“This tragedy illustrates how dangerous work on or near overhead power lines is, and it is imperative that employers ensure there are safe systems of work and that these are implemented and followed. There is no room for error when working with such high voltages.”
UK Power Networks said that its training programmes have since been revised.
The company said in statement: “UK Power Networks deeply regrets Jon’s tragic death, which occurred in a work-related incident on 9 November, 2007. At his inquest in April 2010, the verdict was accidental death.
“We reiterate our condolences to Jon’s family, friends and colleagues. He was well-liked and respected with more than 22 years’ valued service.”