The court heard that police caught the three who were the residents of Ndirande township while vandalising a transformer at Makandi in October this year.
The state also said that the convicts were connected to the string of transformer vandalism at Khonjeni Turn-off, Sports club and Mtambanyama trade centre in the district.
Passing her sentences, Senior Resident Magistrate Assunta Maxwell ordered Mission and Nepiyala to serve a six-year jail term each while Michael (habitual), eight years since their acts disturbed life and business for hundreds of people.
Last month, ESCOM disclosed that it lost over 400 transformers owing to vandalism.
The three come from the area of Traditional Authority Mphuka in Thyolo District.