Homeowner's Guide to Electrical Problems - House Meter Socket
A major component in your home’s electrical system is the main electrical feed coming into the panel board. Between the utility wires and the panel board is the electric meter which is typically installed in a separate meter box, but sometimes they are installed in a panel board with a separate space for the meter. Meter boxes, also known as meter sockets, are often installed outside and mounted on the side of the home.
An electrical meter box is often referred to as Meter Socket, or General Duty Meter Socket.
Another type is a meter socket load center where the electrical meter and panel board are combined into one unit.
Meter sockets are designed for a long lifespan, over 30 years, but they can become defective if the initial installation was below standard. The safe operating life of the meter socket may be reduced by excessive moisture, environmental contaminants, frequent changing of meters, and excessive electrical loads such as overloading or short circuits, vandalism, or storm damage.
As utilities move toward two-way communications for meters and remote meter reading, the opportunity for inspection of meter sockets is expected to decline. In the past utility personnel would visually inspect electric meters during the monthly meter readings, but now the interval between inspections can be upwards to 10 years.
Only utility technicians can inspect the socket because there is a tamper-evident seal on the meter. The National Electrical Manufacturers Association (NEMA) strongly recommends that all existing meter sockets be thoroughly inspected when new electrical meters are installed. The main items to be checked are indications of excessive heating, corrosion, loose connections or components, deformed socket jaws, broken components, failed insulation, or any exposed live parts.
The meter socket is actually the responsibility of the homeowner so if any damage is discovered, the meter socket should be replaced by a qualified electrician immediately.
Problems with Meter Sockets
As the meter socket ages, the jaws which hold the meter in place can become loose if overheated due to an unbalanced load or corrosion forming between the meter terminals and the meter socket jaws. As the jaws begin to heat up and expand, the connection can begin to arc generating more heat and expansion. The jaws can expand to the point where you may lose one leg of your electrical service. If you’ve ever taken the cover off of your panel board you may have notice the black and red wires (or two black wires) connected to the main breaker; each wire carries around 120 Volts into each bus bar where the circuit breakers are attached.
When one leg drops out, some circuits on the other leg will continue to work, while the other circuits will have no power. Also, any 240 Volt appliances will not work such as electric ovens, clothes dryers and air conditioning units.
A precursor to meter socket failure can be flickering lights, especially during high load situations in different areas of the home. The flickering may subside or stop completely when the load is reduced and the connection cools. Once you notice any flickering that occurs over more than one circuit, immediately call your utility company to inspect the meter socket and the wiring from the street to your meter. You can shut off the circuit for the room where you notice the flickering and then check other rooms for similar problems. Receptacles on the same leg can remain powered even if the lights flicker.
If your meter socket needs to be replaced, hire a qualified electrician and make sure they know who your utility company is as deferent utilities may use different meter sockets. The main electrical feed may also need to be replaced if the connection overheated to the point where the insulation on the wire becomes damaged. A meter socket may cost between $70 and $150 depending on the type and expect to pay more if any wire needs to be replaced.