Browse Definitions:
Definition

ground

A ground is a direct electrical connection to the earth, a connection to a particular point in an electrical or electronic circuit, or an indirect connection that operates as the result of capacitance between wireless equipment and the earth or a large mass of conductive material.

Electrical grounding is important because it provides a reference voltage level (called zero potential or ground potential) against which all other voltages in a system are established and measured. An effective electrical ground connection also minimizes the susceptibility of equipment to interference, reduces the risk of equipment damage due to lightning, eliminates electrostatic buildup that can damage system components, and helps protect personnel who service and repair electrical, electronic, and computer systems. In effect, an electrical ground drains away any unwanted buildup of electrical charge. When a point is connected to a good ground, that point tends to stay at a constant voltage, regardless of what happens elsewhere in the circuit or system. The earth, which forms the ultimate ground, has the ability to absorb or dissipate an unlimited amount of electrical charge.

An earth ground usually consists of a ground rod (or a set of ground rods) driven into the soil. At sea, the salt water forms a good earth ground if a corrosion-resistant metal plate having large surface area (such as the hull or keel) is placed in contact with it. In a car, a truck, a boat in fresh water, an aircraft, or a spacecraft, there is no such thing as a true earth ground. But if the mass of metal comprising the vehicle is substantial, that mass can simulate an earth ground reasonably well. An earth ground minimizes the susceptibility of electronic equipment to interference from other devices. In large, base-station wireless installations, a good earth ground also provides a certain measure of protection from the destructive effects of lightning.

A chassis ground is a connection to the main chassis of a piece of electronic or electrical equipment. In older appliances and in desktop computers, this is a metal plate, usually copper or aluminum. In some modern equipment, it is a foil run on the main printed circuit board, usually running around the periphery. Chassis ground is sometimes called common ground. It provides a point that can be considered to have zero voltage. All other circuit voltages (positive or negative) are measured or defined with respect to it. Ideally, all chassis grounds should lead to earth grounds.

In wireless systems, a radio-frequency ( RF ) ground can be obtained by capacitive coupling between devices and the earth. In some cases, several wires known as radials, parallel to and near the earth's surface, are necessary to obtain a good RF ground. At higher frequencies, radials are not always necessary. The capacitance between a handheld radio transceiver or cell phone set and the user's body, and the capacitance between the user's body and the earth, can provide a reasonably good RF ground. Certain types of antenna s can function effectively without an RF ground.

This was last updated in March 2010

Join the conversation

1 comment

Send me notifications when other members comment.

By submitting you agree to receive email from TechTarget and its partners. If you reside outside of the United States, you consent to having your personal data transferred to and processed in the United States. Privacy

Please create a username to comment.

I have in my possession an LED lightbar on the roof of my vehicle. On the plug coming from the leads of the lightbar are 5 wires that are in a plug. This plug connects to another plug with 4 male connectors inside it. Would the ground wire be considered an earth ground?
Cancel

-ADS BY GOOGLE

File Extensions and File Formats

SearchCompliance

SearchSecurity

  • Web application firewall (WAF)

    A Web application firewall (WAF) is a firewall that monitors, filters or blocks traffic to and from a Web application. WAFs are ...

  • MD5

    The MD5 hashing algorithm is a one-way cryptographic function that accepts a message of any length as input and returns as output...

  • identity theft

    Identity theft, also known as identity fraud, is a crime in which an imposter obtains key pieces of personally identifiable ...

SearchHealthIT

SearchDisasterRecovery

  • call tree

    A call tree -- sometimes referred to as a phone tree -- is a telecommunications chain for notifying specific individuals of an ...

  • mass notification system (MNS)

    A mass notification system is a platform that sends one-way messages to inform employees and the public of an emergency.

  • disaster recovery as a service (DRaaS)

    One approach to a strong disaster recovery plan is DRaaS, where companies offload data replication and restoration ...

SearchStorage

  • secondary storage

    Secondary storage is used to protect inactive data written from a primary storage array to a nonvolatile tier of disk, flash or ...

  • VRAM (video ram)

    VRAM (video RAM) is a reference to any type of random access memory (RAM) used to store image data for a computer display.

  • ZFS

    ZFS is a local file system and logical volume manager created by Sun Microsystems to control the placement, storage and retrieval...

SearchSolidStateStorage

  • SSD RAID (solid-state drive RAID)

    SSD RAID (solid-state drive RAID) is a methodology commonly used to protect data by distributing redundant data blocks across ...

  • Tier 0

    Tier 0 (tier zero) is a level of data storage that is faster, and perhaps more expensive, than any other level in the storage ...

  • PCIe SSD (PCIe solid-state drive)

    A PCIe SSD (PCIe solid-state drive) is a high-speed expansion card that attaches a computer to its peripherals.

SearchCloudStorage

  • RESTful API

    A RESTful application program interface breaks down a transaction to create a series of small modules, each of which addresses an...

  • cloud storage infrastructure

    Cloud storage infrastructure is the hardware and software framework that supports the computing requirements of a private or ...

  • Zadara VPSA and ZIOS

    Zadara Storage provides block, file or object storage with varying levels of compute and capacity through its ZIOS and VPSA ...

Close