The Electric Delivery System
Operating the electric grid requires a consistent and coordinated effort by many parties. The production of electricity is called generation, and is measured in kilowatts (one kilowatt is equal to 1,000 watts). The electricity produced by a power plant or generation facility is sold in units called kilowatt-hours. The generation facilities are the first step in providing electricity to customers.
The push of electricity across a cable is measured in volts. The electricity produced by generation facilities is stepped-up or increased in voltage for improved efficiency and transported over long distances by transmission lines. These transmission lines supply substations with electricity, which is then stepped down by large transformers at substations to reduce the voltage for local distribution to businesses and homes.
The distribution lines are the poles and wires common along the streets and roads. These wires deliver the electricity to the customer via service drops or cables. Commercial customers who run heavy machinery usually have three wires to supply their facility, while residential customers have a smaller need with only one supply wire.
Prior to entering the customer’s facility, though, the electricity is stepped down in voltage once more for safety by a smaller distribution transformer. These can usually be seen mounted on a utility pole along the street or located atop a concrete pad. Electricity is moved through the service drop or cable and its supply is measured via a meter before it finally energizes a home's network of electrical wires and outlets.
Customer vs. Utility Responsibilities
Knowing how your electricity is delivered to your home or business is helpful – especially during storms and emergencies – because you are responsible for maintaining or repairing certain portions of the service.
A service drop or cable connects a transformer to the weatherhead or downpipe on your home or business. A service drop is the overhead line which connects a polemount transformer to a weatherhead. A service cables is the underground line that connect a padmount transformer to a downpipe via an underground route. Both the service drop and cable are insulated wires.
A weatherhead or downpipe routes the service drop or cable to the meter. The weatherhead and downpipe are the property of the customer. Although the meter is not owned by the customer, the protective box or “trough” in which it rests is also the property of the customer.
For more information on your responsibilities, please contact us at 888-301-7700 800-852-3339(Capital NH) or 800-582-7276 (Seacoast NH).