Search results
Results from the WOW.Com Content Network
The diagram shows leakage current from an appliance such as an electric motor A flowing through the building's ground system G to the neutral wire at the utility ground bonding point at the service panel. The ground loop between components C1 and C2 creates a second parallel path for the current. [8]
An earth-leakage protection device is a safety device used in electrical installations to prevent shock. It consists of either a current sensing mechanism, or a voltage sensing mechanism. Such devices may be found in the form of either a circuit breaker , known as an earth-leakage circuit breaker ( ELCB ), or built into a socket (aka receptacle ) .
This practice arose from the three-wire system used to supply both 120 volt and 240 volt loads. Because these listed appliances often have components that use either 120, or both 120 and 240 volts, there is often some current on the neutral wire. This differs from the protective grounding wire, which only carries current under fault conditions.
A residual-current device (RCD), residual-current circuit breaker (RCCB) or ground fault circuit interrupter (GFCI) [a] is an electrical safety device, more specifically a form of Earth-leakage protection device, that interrupts an electrical circuit when the current passing through a conductor is not equal and opposite in both directions, therefore indicating leakage current to ground or ...
An earth ground connection of the system dissipates such potentials and limits the rise in voltage of the grounded system. In a mains electricity (AC power) wiring installation, the term ground conductor typically refers to two different conductors or conductor systems as listed below:
A separate pilot wire is run from distribution/ equipment supply system in addition to earth wire, to supervise the continuity of the wire. This is used in the trailing cables of mining machinery. [19] If the earth wire is broken, the pilot wire allows a sensing device at the source end to interrupt power to the machine.
Distance relays are actually double actuating quantity relays with one coil energized by voltage and other coil by current. The current element produces a positive or pick up torque while the voltage element produces a negative or reset torque. The relay operates only when the V/I ratio falls below a predetermined value (or set value). During a ...
The primary reason for the use of isolated grounds (IG) is to provide a noise-free ground return, separate from the equipment grounding (EG) return. The EG circuit includes all of the metal conduit, outlet boxes, and metal enclosures that contain the wiring and must be grounded to provide a safe return path in case of fault currents.