Made a service call. Connect up a large screen TV. Extended the cable (coax) to the sets location. Hooked the cable to the cable box. Pluged in both the TV (3wire cord) and the cable box (2wire cord) I then connected the RCA video & audio cables to the back of the cable box and my helper plugged the rca cables in to the monitor and spark and smoke came out of the cable box. The RCA cable melted. I quickly pulled the plugs. I connected the TV an measured 120v between the cable box (shield) and the TV chassis. Both cable box and TV were plug into a Isolated Ground receptacle. The building was a bank and is now a coffee house. I checked the outlet and found 120v between the ground prong (hole) and the cable shield, and between the ground prong (hole) and the box. I found the breaker controlling the ckt. and turned it off. All voltages gone. Removed the outlet, found it was served by 12/3 bx with BK/WH/RD with the RD connected to the IG ground terminal. Someone had connected this red wire to the hot line in the J box in the ceiling. I removed the hot and installed a propery wired receptacle. The band members has been using this receptacle for their equipment and complained about hum. The fact that all their equipment was electricly hot, it is a wonder someone did not get electrocuted. Always use caution with IG receptacles. Robert
