Three persons, including a Tangedco staff, were arrested on the charge of assaulting a law college student, A. Karthik, 25, near Ondipudur on Monday.
The police said, Ravichandran, 42, a line man and his friends Nagaraj, 24, and Thangaraj, 20, assaulted Karthik with an iron rod when he confronted him for not rectifying a problem over the power supply.
Karthik has been admitted to the Coimbatore Medical College Hospital.
A case had been registered under Sections 75 (nuisance), 324 (causing grievous hurt) and 506 (ii) (criminal Intimidation) of Indian Penal Code.