EE WAS CLEANING GREASE ON FLOOR OF 2300 P&H ELECTRICAL SHOVEL. THE EE WAS UTILIZING A METAL ROD APPROX. 3' IN LENGTH. THE METAL ROD WAS BEING USED TO PUSH RAG ALONG THE FLOOR OF SHOVEL BY THE HOIST DRUM. WHILE PUSHING THE RAG ACROSS THE FLOOR THE STICK WENT INTO A HOLE APPROX. 6"" IN DIAMETER LOCATED ON SHOVEL FLOOR. STICK CAME IN CONTACT W/SHOVEL COLLECTER RING CAUSING ELECTRICAL F