It happened at 10:45 a.m. Tuesday in the 900 block of Cherry Street.
PECO spokesman Ben Armstrong said it does not appear anyone called PA One Call before digging.
"It is always essential, if you're going to be digging underground, to call PA One Call at 811. PA One Call is the state run utility line marking service so you can dig safely to minimize danger or injury," said Armstrong.
The worker was being treated at Jefferson University Hospital.
208 customers lost power after the incident, but most have been restored.