Members of IBEW Local 614 approved the agreement with 97-percent support.
PECO workers have voted to authorize a strike.
A union representing more than 1,500 PECO workers has set a date for a strike authorization vote.
Action News spoke with Pennsylvania Governor Josh Shapiro, who said he was against the rate hikes. He made that known to PECO.
While utilities like PECO handle distribution, customers are allowed to choose their own third-party supplier for the supply portion - a move that can result in savings of up to 30 percent.
IBEW Local 614 represents about 1,500 PECO employees who work as linemen, gas technicians, mechanics, call center workers and back office workers.