It is very rare for a homeowner to work on the electric meter that monitors current usage in the home. This device, which provides the connection point where electrical power passes through the wall of the home to reach the main service panel, is officially owned by the power company, not the homeowner. Therefore, any wiring connections should be handled by a professional electrician or by a technician from the power company. In fact, homeowners may be forbidden to work at the electric meter in any way. But it can still be useful to understand the functioning of the electric meter and the particulars of how it is wired.
Anatomy of an Electric Meter
Inside a standard household electric meter box, there is a center neutral bus bar with wire connection lugs at each and two hot bus bars, each with wire connections lugs at each end. There is also a connection lug for the grounding wire, which is bonded to the center neutral bus bar. None of these wire connection lugs is visible unless the meter mechanism itself is removed from the box.
The actual wire connections are quite easy to understand. Three large-gauge stranded wires (two hot wires and one neutral) enter the meter box from a weather head on a metal mast (or from underground service) and are attached to the corresponding line terminals on the hot and neutral bus bars in the meter box. These feeder wires are known as the line wires. The load wires running to the indoor circuit breaker panel are connected to the remaining load terminals on the bus bars. And the grounding wire running to the grounding rod is connected to the grounding lug inside the meter box.
The process by which an electrician or utility technician connects an electric meter involves making a total of seven simple wire connections: three line connections, three load connections, and a grounding connection.
Source: The Spruce
