We are setting gfi trip settings at a hospital and the general Electric tech. called me a told me he was reading 30A to ground at the main switchboard.The main switchboard is made up of two sections of outdoor switchboard. the orginal is a 4000A MLO. We added a second section with a 2500A MCB. when we open the 2500A MCB to ampe reading drops to 1.5 to 2 amps.