IBEW Local 614 said the incidents happened at three separate locations.
In one incident, the union said a striking worker was pushed to the ground by PECO security at PECO's Oregon Avenue facility.
At the Berwyn Yard in Tredyffrin Township, the union said a member was walking in front of a PECO truck when the vehicle lurched forward, made contact, and struck him.
Also at the Berwyn Yard, the union said a striking Local 614 member was struck by a vehicle driven by a third party.
However, a PECO spokesperson said in a statement to Action News, "Based on our investigations, these accusations are completely false."
The walkout began at 12:01 a.m. following months of negotiations.
The workers - including linemen, gas technicians, mechanics and call center employees who serve millions of customers across five counties - walked out at the start of the holiday weekend and amid an ongoing heat wave.
The union said it is seeking fair wages that meet industry standards, a universal pension plan, retirement medical benefits and a unified contract for all workers.
PECO said its proposal includes nearly a 20 percent wage increase over five years, along with significantly enhanced retirement and medical benefits.
PECO says it has comprehensive plans in place to maintain operations.