Reference

EV charger glossary

Plain-English definitions for the terms that show up in EV charger quotes, spec sheets, and electrical scopes.

32 entries with cross-references and entity links.

Reference glossary for Level 2 EV charger and home-charging terminology — charging levels, connector standards like J1772 and NACS, the NEMA 14-50 outlet, electrical terms like ampacity, continuous load, and the 125 percent rule, panel and service upgrades, plus Oregon licensing and the Central Electric Co-op rebate, with links to authoritative sources where applicable. Useful when comparing EV charger quotes that use unfamiliar technical language, or when reading a spec sheet before you sign.

125 percent rule: The code requirement that a circuit serving a continuous load be sized to 125 percent of that load. For EV chargers this sets the breaker and wire: a 40-amp charger needs a 50-amp circuit, a 48-amp charger needs a 60-amp circuit. It keeps conductors from overheating under a long continuous draw.

Ampacity: The maximum current, in amperes, that a conductor can carry continuously without exceeding its temperature rating. Wire gauge is chosen so its ampacity meets or exceeds the circuit’s sized load. Undersized wire on a continuous EV load runs hot — a real safety issue, not a detail to economize on.

Battery electric vehicle (BEV): A vehicle powered solely by a battery and electric motor, with no internal combustion engine, which relies entirely on charging. BEVs typically benefit most from Level 2 home charging because their daily range demand outpaces what Level 1 can replace overnight.
BCD electrical license: The electrical contractor license issued under Oregon’s Building Codes Division, required to perform electrical work such as an EV charger circuit. Together with CCB registration, it is the licensing baseline for a Level 2 install in Oregon.

Continuous load: An electrical load expected to draw at its maximum for three hours or more, which an EV charger does. The National Electrical Code requires circuits for continuous loads to be sized to 125 percent of the load, which is why a 48-amp charger needs a 60-amp circuit.
Central Electric Cooperative (CEC): A member-owned electric utility serving much of Deschutes County and Central Oregon. CEC offers up to a $450 residential Level 2 charger rebate for qualifying members; not every address in the area is in CEC territory, so eligibility should be confirmed.

Dedicated circuit: A branch circuit that serves only the EV charger, with its own breaker and conductors sized for the load. A Level 2 charger requires a dedicated 240V circuit; sharing it with other loads is not permitted and would trip or overheat.
Double-pole breaker: A circuit breaker that occupies two panel spaces and connects to both legs of a split-phase service to provide 240V. A Level 2 EV circuit lands on a double-pole breaker sized to the circuit (for example a 50-amp breaker for a 40-amp charger).

EV charging station (EVSE): Electric vehicle supply equipment — the wall- or pedestal-mounted unit that delivers electricity from a building’s wiring to an electric vehicle’s onboard charger through a connector. Despite the name, the EVSE does not convert power itself; it safely supplies AC to the car, which converts it. A home Level 2 unit runs on a dedicated 240V circuit.
Electrical panel (load center): The distribution board where the utility service feeds the home’s branch circuits through breakers. Its rating — commonly 100A or 200A — and its available capacity and open spaces determine whether it can take an EV circuit as-is.
Electrical permit: The authorization from the local building department to perform electrical work, followed by an inspection. An EV charger install in Oregon requires an electrical permit and inspection, which protect the homeowner and are often expected for rebate eligibility.

Grounding and bonding: The safety practice of connecting non-current-carrying metal parts to ground and bonding the system so a fault has a safe path and breakers trip. Every EV circuit must be properly grounded and bonded — part of a code-compliant, inspected install.
GFCI protection: Ground-fault circuit-interrupter protection that opens a circuit when it detects current leaking to ground, guarding against shock. EV-circuit GFCI requirements depend on the install type and code edition; hardwired and outlet installs handle it differently, which a licensed electrician sorts.

Hardwired install: An EVSE wired directly to the branch circuit rather than plugged into an outlet. Hardwiring can run a higher continuous amperage than a NEMA 14-50 outlet allows and is favored for the fastest home charging, a long run, or a clean permanent install.

kW (kilowatt): A unit of power equal to 1,000 watts, used to describe charging rate. Level 2 charging power is roughly the circuit voltage times the amperage, so higher amperage means more kW and faster charging — up to the limit of the car’s onboard charger.

Level 1 charging: Charging from a standard 120V household outlet using the cordset that comes with the car. Level 1 adds only a few miles of range per hour, which can suit a plug-in hybrid or a low-mileage driver but is slow for most full electric vehicles.
Level 2 charging: Charging from a dedicated 240V circuit and a Level 2 EVSE, the standard for home charging. Level 2 charges several times faster than Level 1, with speed set by the circuit amperage, and is the level most full-EV owners install at home.
Level 3 / DC fast charging: High-power direct-current charging that bypasses the car’s onboard charger to deliver DC straight to the battery, charging far faster than Level 2. It requires commercial-grade equipment and service and is found at public charging stations, not in homes.
Load calculation: The process of totaling a home’s connected electrical load and comparing it to the service rating to determine available capacity. It is what decides whether a panel can add an EV circuit, at what amperage, or whether an upgrade is needed first. The deciding number, not the panel rating on the door.
Load management (load sharing): Equipment that limits or shares circuit capacity dynamically, so an EV charger backs off when the rest of the home is drawing heavily, or two chargers split a circuit. It can fit charging onto a panel that could not otherwise carry a full-amperage circuit, and is common for multiple EVs.

Multi-unit charging: EV charging wiring for more than one vehicle or unit — a second car, an ADU, a duplex, or a small multi-family property — planned as one job with subpanels and load management so the service is not overrun.

North American Charging Standard (NACS): The connector standard developed by Tesla and now being adopted by many automakers across North America. NACS handles both AC and DC charging on one connector. Adapters allow J1772 and NACS equipment and vehicles to work together during the transition.
NEMA 14-50 outlet: A 240V receptacle — the same one used for electric ranges and RVs — installed on a dedicated 50-amp circuit, commonly used for plug-in Level 2 chargers. Because EV charging is a continuous load, a 14-50 typically supports up to a 40-amp charging draw. It lets a portable EVSE be unplugged and moved.

Onboard charger: The component inside the electric vehicle that converts the AC supplied by a Level 1 or Level 2 EVSE into DC to charge the battery. Its rating caps how many amps the car can accept on AC charging, so a circuit sized above that ceiling does not charge faster.
Oregon CCB: The Oregon Construction Contractors Board, with which contractors must register to perform construction work in the state. An EV charger installer should hold valid CCB registration in addition to the electrical-specific license.

Plug-in hybrid (PHEV): A vehicle with both a battery that can be charged from the grid and a gasoline engine. Because PHEV batteries are smaller, Level 1 charging is often enough, though some owners still add Level 2 for convenience.

SAE J1772: The standard connector — the "J-plug" — used for Level 1 and Level 2 AC charging on most non-Tesla electric vehicles in North America. A home EVSE typically uses a J1772 connector, and adapters bridge J1772 and the NACS connector.
Service rating: The maximum current the electrical service and main panel are rated to carry, typically 100A or 200A for a home. The rating is a ceiling, not a measure of free capacity — a 200-amp panel can still be effectively full depending on its existing loads.
Service upgrade: Increasing a home’s electrical service capacity — for example from 100A to 200A — when a load calculation shows the existing service cannot carry a new load such as an EV circuit. It is utility-coordinated, permitted, and inspected, and is licensed electrical work.
Subpanel: A secondary panel fed from the main service that adds breaker spaces. When a service has capacity but no open slots, or when multiple circuits are being added, a subpanel can be a simpler, cheaper solution than a full service upgrade.

Voltage drop: The loss of voltage along a conductor over distance, which grows with length and current. On a long EV-circuit run, conductors may be upsized beyond the minimum ampacity to keep voltage drop within acceptable limits so the charger gets the voltage it needs.

Wire gauge (AWG): The American Wire Gauge system that sizes conductors; a smaller AWG number means thicker wire and higher ampacity. The gauge for an EV circuit is chosen for the sized amperage and the run length — a longer run at higher amperage may need a heavier gauge to limit voltage drop.

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