AC

Short for Alternating Current.

DC

Short for Direct Current.

Electrons

Small charged particles that exist as part of the molecular structure of materials.

Free electron

An electron that is easily separated from the nucleus of the atom to which it belongs.

Conductors

Bodies that possess free electrons (metals, for example, but also the human body and the earth).

Insulators

Bodies that do not possess free electrons (e.g., glass, plastic and wood).

Voltage (U)

The difference in charge between two points.

Current (I)

The rate at which charge is flowing.

Resistance (R)

A material's tendency to resist the flow of charge (current).

Circuit

A closed loop that allows charge to move from one place to another.

Resistor

Any material that allows electrical energy to be converted to thermal energy.

Overload

Additional power available for a short amount of time.

VRLA Battery

Short for Valve Regulated Lead Acid Battery.

Absorption voltage range

The level of charge that can be applied without overheating the battery.

Float voltage range

The voltage at which a battery is maintained after being fully charged.

Distribution Panel:

This is a circuit breaker and contains many electrical circuits. Using this, a circuit can be turned on or off.

Circuit breakers and Fuses:

These protect wires from overheating and are found in the distribution panel box. When there is an overload, that is, too much current flowing, the fuses will blow or the circuit breakers will trip. Fuses and circuit breakers are rated so therefore at a particular current, they will be damaged by the circuit will be off.

Switches:

Switches can energize circuits, that is, they allow a current to flow through. If carelessly used, these can cause damage to a person and to equipment. Receptacles connect the appliances to a circuit.

Grounding/earthing

connecting metal parts of electric appliances to earth.