Damn!
Was the plate chiller drained or was it full with that Easy Clean solution? BTW, it's not the same as PBW.
If full, you may be able to taste it, but I don't think it will kill ya, look at the ingredients. They'll be very diluted in 5 gallons. It may screw with your pH a bit too (raise it). Your plate chiller holds about 300-600 ml depending on build and model.