Electrical Systems Grounding

grounding

A broad term referring to the intentional act of making a permanent low-impedence, electrically conductive path to the earth. This term is used in a general way to encompass the overall subject.

System Bonding Jumper

A conductor that connects between the grounded circuit conductor and the supply-side bonding jumper, or the equipment grounding conductor, or both, at a separately derived system

Equipment grounding conductor (EGC)

A conductor used to connect non current-carrying metallic parts of equipment to the system grounding busbar. The equipment grounding conductor is part of the equipment grounding path.

Ground Fault Circuit Interrupter (GFCI)

A device designed to open an electrical circuit when a ground fault occurs

grounding electrode

A device that establishes an electrical connection to the earth

bonding jumper

Conductors used for bonding

grounded

Connected to the earth through a conductor, such as a driven pipe or metal plate

the bonding jumpers must be the same size or larger than the grounding electrode conductor

Due to the high currents available on the supply side of the service equipment, the bonding jumpers must be ____________ than the grounding electrode conductor.

Unspliced Main Bonding Jumpers

For a grounded system, which type of jumper shall be used to connect the equipment grounding conductors and the service disconnect enclosure to the grounded conductor of the system within the enclosure for each service disconnect?

grounding electrode conductor (GEC)

The conductor used to connect the grounding electrode(s) to the equipment grounding conductor

bonding

The mechanical joining of metallic parts to form an electrically conductive path. This path should have as little resistance as possible, and the joints should be mechanically sound and permanent.

True! all electrical equipment installed in a damp or wet location must be grounded

True/False all electrical equipment installed in a damp or wet location must be grounded

True! Most circuits require grounding

True/False most circuits require grounding

True! Grounding is the most important and least understood area of code

True/False? Grounding is the most important and least understood area of code

True! Improper grounding can be as dangerous as no grounding.

True/False? Improper grounding can be as dangerous as no grounding.

System grounding and Equipment grounding

What are the two types of grounding?

to eliminate currents from traveling through non current-carrying components of electrical systems.

What is the purpose of grounding?

grounded conductor

a circuit conductor that serves as part of the system grounding path. Often called the neutral.

Main bonding jumper

a conductor that connects between the grounded circuit conductor and the equipment grounding conductor at the service.

Equipment bonding jumper

a conductor that connects two or more portions of the equipment grounding conductor

triad

a ground rod grouping that ensures grounding integrity

ground

a path from a circuit or equipment to the earth. It can be an intentional or accidental connection.

made electrodes

electrodes that serve no other purpose

equipment grounding

in addition to circuit grounding, metal enclosures and and parts that could be energized must also be grounded (the connection of non current-carrying metal items to the ground)

system grounding

one circuit conductor of each circuit is connected to the ground. This connection is made at the service-entrance equipment

Arc Fault Circuit Interruptors AFCI

opens the circuit when an arc fault is detected. Also detects arcing faults that are not typically detected by standard breakers or GFCI's

Required conditions for ac circuits less than 50 volts

the transformer supplying the voltage has a source that exceeds 150 volts to ground, the overhead conductors are installed outdoors, and the transformer supplying the voltage receives its supply from an ungrounded source.

true! equipment must never ever be grounded to the grounded conductor (neutral) on the load side of the service. This would create a very dangerous situation

true/false? equipment must never be grounded to the grounded conductor (neutral) on the load side of the service.

damaged wires, frayed conductor insulation, loose electrical connections, overheated or otherwise stressed electrical chords, damaged electrical appliances

typical conditions that may generate arc faults