Why is it dangerous to use a Nonmetallic-Sheathed cable (NM) grounding conductor as a neutral?
Using the grounding conductor as the neutral creates an ungrounded circuit. There is no grounding conductor available for clearing ground faults. Explanation: Sometimes this is found at retrofit ceiling fan installations or where an outlet has been added at a switch box. Also, it can be found at well pumps and AC disconnects where one leg of a 240-volt circuit is tapped and the grounding conductor is used as a neutral to run a light or 120-volt receptacle. The frame of the fan, yoke of the device and metal box are not grounded (bonded). Just as with the false ground, any contact between these parts and a grounded object will result in current flow. Anyone working on the circuit would not expect neutral current to be flowing on the grounding conductor and could get shocked or electrocuted if he or she disconnected it. In the event of a ground fault on the metallic parts of the connected equipment, there would be no way to clear the fault and the metallic portions of the equipment would
