different context but I do have experience with this. I'd call PECO first, and ask if they can come out and check your box to see if it's properly set up. In 2012 I had them come out only to find that the water heater to the upstairs unit where I lived was hooked up to my breakers. In the roughly 7 years I had lived there they estimated I paid anywhere from 5k-7k extra in electric costs because of that.