Trafford Magistrates’ Court heard that new street lights had recently been installed on the road and the old lights had been disconnected.
The injured worker and a colleague were removing one of the old lamp posts using a jackhammer to break the concrete around the base when he struck a mains electricity cable.
An HSE probe discovered the two workers had not been given service drawings for the lamp post which would have shown where the mains cable ran.
Their manager had also not received any health and safety management training, despite it being part of his job to ensure work was carried out safely.
Bury Metropolitan Borough Council was fined £20,000 and ordered to pay £7,594 in costs after pleading guilty to safety breaches.
Speaking after the hearing, HSE Principal Inspector John McGrellis said: “The council employee needed several days off work to recover from his burn injuries but he could easily have been killed.
“He shouldn’t have been put in a situation where he didn’t know what the potential dangers were as he used a jackhammer to break up the concrete around the lamp post.
“It’s vital that people carrying out work near to power lines receive appropriate supervision and training to ensure their safety.”