Search results
Results from the WOW.Com Content Network
Two-phase electrical power was an early 20th-century polyphase alternating current electric power distribution system. Two circuits were used, with voltage phases differing by one-quarter of a cycle, 90°. Usually circuits used four wires, two for each phase. Less frequently, three wires were used, with a common wire with a larger-diameter ...
One voltage cycle of a three-phase system. A polyphase system (the term coined by Silvanus Thompson) is a means of distributing alternating-current (AC) electrical power that utilizes more than one AC phase, which refers to the phase offset value (in degrees) between AC in multiple conducting wires; phases may also refer to the corresponding terminals and conductors, as in color codes.
During installation of a generator, careful checks are made to ensure the generator terminals and all control wiring is correct so that the order of phases (phase sequence) matches the system. Connecting a generator with the wrong phase sequence will result in large, possibly damaging, currents as the system voltages are opposite to those of ...
A generator in electrical circuit theory is one of two ideal elements: an ideal voltage source, or an ideal current source. [1] These are two of the fundamental elements in circuit theory. Real electrical generators are most commonly modelled as a non-ideal source consisting of a combination of an ideal source and a resistor.
As an example, a 250 kVA motor–generator operating at 300 ampere of full load current will require 1550 ampere of in-rush current during a re-closure after 5 seconds. This example used a fixed mounted flywheel sized to result in a 1 ⁄ 2 Hz per second slew rate. The motor–generator was a vertical type two-bearing machine with oil-bath ...
Due to high cost of a generator, a set of sensors and limiters will trigger the alarm when the generator approaches the capability-set boundary and, if no action is taken by the operator, will disconnect the generator from the grid. [3] D-curve expands with cooling. The D-curve for a particular generator can be expanded by improved cooling.
Get AOL Mail for FREE! Manage your email like never before with travel, photo & document views. Personalize your inbox with themes & tabs. You've Got Mail!
Three-phase transformer with four-wire output for 208Y/120 volt service: one wire for neutral, others for A, B and C phases. Three-phase electric power (abbreviated 3ϕ [1]) is a common type of alternating current (AC) used in electricity generation, transmission, and distribution. [2]