Glossary: C

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C

C10

Symbol for ampere-hour capacity of a battery at the 10-hour discharge rate, to a specified end voltage.

C100

Symbol for ampere-hour capacity of a battery at the 100-hour discharge rate, to a specified end voltage.

C20

Symbol for ampere-hour capacity of a battery at the 20-hour discharge rate, to a specified end voltage.

C5

Symbol for ampere-hour capacity of a battery at the 5-hour discharge rate, to a specified end voltage.

Capacitance

An electrical effect in AC circuits that results in amperage peaking before voltage.

Cathode

The electrode within a battery cell that undergoes the chemical process of reduction. Electrically, the cathode is the negative terminal of the cell.

Cathodic Protection

Systems that protect metal from corrosion by running small electrical currents along the metal. Most often used to protect well heads, and oil, gas, and water pipelines.

CB

Circuit Breaker: A device for manually opening (breaking) or closing a circuit to interrupt or apply electric power to an electrical apparatus. A circuit breaker can also open a circuit automatically when it senses an overload.

CE

Conformite Europeene (European Conformity)

Cell (battery)

A single unit of an electro-chemical device capable of producing an electrical current by converting chemical energy into electrical energy. The cell is the basic unit used to store energy in the battery. The cell contains an anode, a cathode, and the electrolyte. A battery usually consists of several cells electrically connected together to produce higher voltages. (Sometimes the terms cell and battery are used interchangeably).

Cell (solar)

The smallest, basic photovoltaic device that generates electricity when exposed to light.

CFL

Compact Fluorescent Light: A smaller version of standard fluorescent lamps that can directly replace incandescent lights. CFLs use 65 to 80 percent less energy, while producing the same lumens.

Charge Controller

A component of photovoltaic system that controls the flow of current to and from the battery to protect the batteries from over-charge and over-discharge. The charge controller may also indicate the system operational status. Standard charge controllers vary the current (A) based on preset voltage set points.

Charge Rate

The current applied to a cell or battery to restore its available capacity. This rate is commonly normalized by a charge control device with respect to the rated capacity of the cell or battery. A C/20 rate is a charge rate that is 1/20th of the total battery capacity. Also called a “20-hour rate.”

Circuit

A group of electrical components that make a complete electrical path, providing some function.

Circuit Breaker

A circuit breaker is an automatically operated electrical switch designed to protect an electrical circuit from damage caused by overload or short circuit. Its basic function is to detect a fault condition and interrupt current flow. Unlike a fuse which operates once and then must be replaced, a circuit breaker can be reset (either manually or automatically) to resume normal operation.

Circuit Breaker (CB)

A device for manually opening (breaking) or closing a circuit to interrupt or apply electric power to an electrical apparatus. A circuit breaker can also open a circuit automatically when it senses an overload.

Clean Power

Electrical power which has been conditioned and/or regulated to remove electrical noise from the output power.

Closed Loop System

A solar hot water system of which no part is vented to the atmosphere or fed with fresh liquid. The system liquid, usually some form of antifreeze solution, is re-circulated. Closed loop solar systems are also known as glycol systems and indirect systems.

Cob Construction

A traditional building technique using hand formed lumps of earth mixed with sand and straw.

Collector Loop

The plumbing loop in a solar hot water system that includes the solar collectors. The collectors heat the fluid in the collector, and the heated fluid can be used directly (if water) or the heat can be exchanged to a potable water loop.

Combiner Box

A box where wires from individual PV modules or strings are combined into larger wires to run to the battery bank. Can also contain over current protection devices.

Compact Fluorescent Light (CFL)

A smaller version of standard fluorescent lamps that can directly replace incandescent lights. CFLs use 65 to 80 percent less energy, while producing the same lumens.

Concentrator

A photovoltaic module that includes optical components, such as lenses, to direct and concentrate sunlight onto a solar cell of smaller area. Most concentrator arrays must directly face or track the sun.

Conduction

Heat transfer from a hot object to a colder object through direct contact.

Conductor

A material with relatively low resistance through which electricity will readily flow—wires, cables, bus bars. The most common conductors are copper and aluminum.

Conduit

Metal or plastic tubing designed to protect electrical conductors.

Configuration file

The information or data loaded into and the supervisory module that controls the behavior of an power system to suit the particular requirements of a customer’s site or installation.

Configurations Database

This is the total set of configurable parameters.

Conformite Europeene (European Conformity)

CE marking is used to signify that a product complies with all the applicable performance and safety standards adopted by the members of the European Union and is therefore certified for sale in European Union countries.

Continuous Output Rating

The maximum amount of power an inverter may deliver to a load (or loads) for a sustained period of time.

Convection

Heat transfer by the movement of fluid (usually air or water). Heat transfer through either the natural or forced movement of air.

Converter

A device which changes electrical energy from one form to another, such as from alternating current to direct current.

Crystalline Silicon

A type of PV cell made from a single crystal or polycrystalline slice of silicon.

Current

Amount of electricity that flows through a conductor, such as a wire.

Current Share

A process used to balance output currents between rectifiers. See Active Current Share.

Cutoff Voltage

Electrical equipment setting for the voltage level at which a battery is considered to be empty, and the discharge process is terminated. Most commonly found in inverters and charge controllers that include a feature for low voltage disconnection.

Cycle

One complete charge/discharge cycle of a battery. An AC sine wave’s movement from zero to maximum positive, through zero, to maximum negative, and back to zero.

Cycle Life

Cycle life is the number of cycles a cell or battery will undergo before being considered “worn out.” This point is usually defined as when the battery’s capacity has decreased to 80 percent of its initial rated capacity.