The three contract workers electrocuted on July 23 when a concrete electric post, which they were trying to erect for a new connection, accidentally got in touch with an 11-KV live wire.
Riju and Joy, who were suspended after the incident, had not switched off the line which amounted to dereliction of duty and neglect, police said.
Police said that charges had been framed against them under section 304A (causing death by rash or negligent act) of the Indian Penal Code.