Understanding the Terms

The diagrams below illustrate and define the common terms encountered during a new electric or gas service installation project. Click on any of the numbers for a detailed view of the components involved, and hover over any of the orange triangles in the resulting diagram to see a description of the component.

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  • Service drop magnified

    Service drop

    Wire that connects a customer's weather head (on top of the roof) to the electric pole. Service drops are maintained by PG&E; the weather head is maintained by the customer.

  • Weather head magnified

    Weather Head

    Periscope structure made of metal conduit that the customer's electric service wire passes through as the point of contact with PG&E's overhead service drop line.

  • Secondary distribution line extension magnified

    Secondary Distribution Line Extension

    The output side of a transformer and the circuit connected with it. Voltage delivered between 0 and 750 volts. Also referred to as service delivery voltage.

  • Primary distribution line extension magnified

    Primary Distribution Line Extension

    High voltage or input side of a transformer. Includes the circuit that feeds into the transformer.

  • Transformer magnified

    Transformer

    Device which permits changing the high voltage needed for distribution down to the lower voltage for customer use. Overhead transformers are usually bolted to a wood pole and connected by overhead high voltage cables to individual customer service meters. Underground, transformers are usually green steel cabinets mounted on concrete pads and connected by underground high voltage cables to individual customer service meters.

  • Cross arm magnified

    Cross Arm

    Horizontal brackets (typically wooden) mounted on the pole to which wires are attached to conduct electricity.

  • Insulator magnified

    Insulator

    Glass or porcelain fixtures which insulate conductors and the current they are carrying from returning to ground.

  • Riser magnified

    Riser

    Installation on a pole which connects underground distribution facilities to over head facilities.

  • Weather Head magnified

    Weather Head

    Periscope structure made of metal conduit that the customer's electric service wire passes through as the point of contact with PG&E's overhead service drop line.

  • Circuit Breaker magnified

    Circuit Breaker

    Device used to interrupt flow of electric current when the circuit is suddenly overloaded and the current exceeds a preset limit.

  • Electric Panel magnified

    Electric Panel

    Service center on the customer site that contains equipment such as fuses, breakers, and meters.

  • Ground Fault Circuit Interrupter magnified

    Ground Fault Circuit Interrupter (GFCI or GFI)

    A specific type of circuit protection that is commonly required in kitchens, garages, bathrooms and anywhere else that water is in close proximity. The devices help safeguard against electrical shock and are available as an outlet or a breaker.

  • Main Switch magnified

    Main Switch

    Device used to protect customer equipment installed past the meter.

  • Service Delivery Point & Electric Meter magnified

    Service Delivery Point & Electric Meter

    Specific location at a premise where PG&E supplies service (e.g., electric meter, gas meter).

  • Weather Head magnified

    Weather Head

    Periscope structure made of metal conduit that the customer's electric service wire passes through as the point of contact with PG&E's overhead service drop line.

  • Customer-owned temporary service pole magnified

    Customer-owned temporary service pole

    Poles that are not owned, operated, or maintained by PG&E.

  • Service Line/Pipe magnified

    Service Line/Pipe

    Pipeline, valves, and fittings that carries natural gas from a distribution main up to the gas meter at a building.

  • Service Delivery Point &Gas Meter magnified

    Service Delivery Point & Gas Meter

    Specific location at a premise where PG&E supplies service (e.g., electric meter, gas meter).

  • Gas Houseline magnified

    Gas Houseline

    Small pipes (1 to 3/4 inch in diameter) running out of the meter and onto the property that carry natural gas to home appliances.

  • Branch Service magnified

    Branch Service

    Service that is not connected to a gas main and has another service as its source of supply.

  • Circuit Breaker magnified

    Circuit Breaker

    Device used to interrupt flow of electric current when the circuit is suddenly overloaded and the current exceeds a preset limit.

  • Electric Panel magnified

    Electric Panel

    Service center on the customer site that contains equipment such as fuses, breakers, and meters.

  • Ground Fault Circuit Interrupter magnified

    Ground Fault Circuit Interrupter (GFCI or GFI)

    A specific type of circuit protection that is commonly required in kitchens, garages, bathrooms and anywhere else that water is in close proximity. The devices help safeguard against electrical shock and are available as an outlet or a breaker.

  • Main Switch magnified

    Main Switch

    Device used to protect customer equipment installed past the meter.

  • Service Delivery Point &Electric Meter magnified

    Service Delivery Point & Electric Meter

    Specific location at a premise where PG&E supplies service (e.g., electric meter, gas meter).

  • Electric Service Extension magnified

    Electric Service Extension

    Extension of electric service from the main energy supply line to the customer's facility.

  • Splice Box magnified

    Splice Box

    Device found in underground systems used to enclose splices in cables so that they may be readily accessible for repair.

  • Conduit magnified

    Conduit

    Ducts, pipes, or tubes of certain metals, plastics or other materials acceptable to PG&E (including pull wires and concrete encasement where required) for the installation and protection of electric wires and cables.

  • Cabling magnified

    Cabling

    Conductors (including cable-in-conduit, if used), connectors, switches, as required by PG&E for primary, secondary, and service installations.

  • Electric Panel magnified

    Electric Panel

    Service center on the customer site that contains equipment such as fuses, breakers, and meters.

  • Splice Box magnified

    Splice Box

    Device found in underground systems used to enclose splices in cables so that they may be readily accessible for repair.

  • Conduit magnified

    Conduit

    Ducts, pipes, or tubes of certain metals, plastics or other materials acceptable to PG&E (including pull wires and concrete encasement where required) for the installation and protection of electric wires and cables.

  • Cabling magnified

    Cabling

    Conductors (including cable-in-conduit, if used), connectors, switches, as required by PG&E for primary, secondary, and service installations.

  • Ground Rod magnified

    Ground Rod

    Installed in accordance with the National Electric Code (NEC), grounding provides an electrical connection between non-current-carrying metallic parts of equipment and the earth to limit the voltage imposed by lightning, line surges, and contact with higher voltage lines.

  • Protective Structures magnified

    Protective Structures

    Fences, retaining walls (in lieu of grading), sound barriers, posts, or barricades and other structures as required by PG&E to protect distribution equipment.

  • Transformer magnified

    Transformer

    Device which permits changing the high voltage needed for distribution down to the lower voltage for customer use. Overhead transformers are usually bolted to a wood pole and connected by overhead high voltage cables to individual customer service meters. Underground, transformers are usually green steel cabinets mounted on concrete pads and connected by underground high voltage cables to individual customer service meters.

  • Gas Distribution Main magnified

    Gas Distribution Main

    Mains, service connections, and equipment that carry or control the supply of natural gas from point of local supply to and including the meter.

  • Trench magnified

    Trench

    Excavation that intentionally provides for more than one service, such as gas, electricity, cable television, telephone, etc.

  • Electric Distribution Line magnified

    Electric Distribution Line

    PG&E's overhead and underground lines, consisting of poles, power lines, substations, and transformers, which supply two or more services to homes and businesses.


More detailed technical information about connecting to the PG&E system can be found in the Electric and Gas Service Requirements.

Additional information about the process for a new electric or gas service project is available at Building and Renovation Process.

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