The electricity meter is the device used by the power company to monitor your electrical usage. It is usually a clear glass meter that looks like an oversize mason jar and contains a number of measuring devices such as dials and wheels on older models or a digital display on newer ones.
The meter uses a set of voltage and current measurements to calculate the energy used by the load or supply. These meters are generally divided into voltmeters and ammeters.
A voltmeter measures the voltage of a single-phase AC supply and an ammeter measures the current. In many areas, these meters are located in-line between the source and the customer (or in the customer’s own meter box), while in other areas they are installed away from the service conductors, such as on a pole or on a shelf inside a building.
An electric meter diagram can be useful to help understand how an electric meter works and to ensure that the meter is wired properly for your home or business. However, it should be noted that homeowners may not be allowed to work on their meter or to make any wiring connections to it without the approval of the power company.
How to connect an electric meter: 1. Line side, 2. Load side, 3. Grounding connection
When it comes time to install an electric meter in your home or business, the process is relatively simple. The first step is to remove the meter from its box and disconnect the circuit breaker.
Next, an electrician or utility technician will need to connect the meter base to the main service breaker panel. Then, he or she will need to make several wire connections, including three line connections, three load connections and a grounding connection.
A basic electric meter base has a neutral bus bar in the middle and two hot bus bars at each end, with wire connection lugs at each. The wire connections from the weather head, or from the underground service, enter the meter base and are attached to the appropriate terminals on these bus bars.
In some cases, the neutral connection on a meter base is also connected to the neutral bus bar in the main service breaker panel. This is an important step because it prevents any shorts from entering your house or business from the meter base to your equipment, which can cause serious injury.
The other connections that need to be made are for the feeder wires, which enter the meter box from the outdoor weather head or from underground service. These feeder wires are known as the line wires, and they run from the weather head or underground service to the line terminals on the hot and neutral bus bars in the lower section of the meter base.
Depending on the type of electric meter, these wire connections are made on either the line side or the load side of the meter base. A single phase wire and a system neutral will typically be attached to the same wire connection in the meter base, while three phase wires will have separate connections to the hot and neutral bus bars on the upper part of the meter base. The meter base should also have a grounding connection bonded to the center neutral bus bar.