Search results
Results from the WOW.Com Content Network
In the very early days of commercial electric power, some installations used two-phase four-wire systems for motors. The chief advantage of these was that the winding configuration was the same as for a single-phase capacitor-start motor and, by using a four-wire system, conceptually the phases were independent and easy to analyse with mathematical tools available at the time.
Self-starting polyphase induction motors produce torque even at standstill. Available squirrel-cage induction motor starting methods include direct-on-line starting, reduced-voltage reactor or auto-transformer starting, star-delta starting or, increasingly, new solid-state soft assemblies and, of course, variable frequency drives (VFDs). [39]
Schematic of a capacitor start motor. A capacitor start motor is a split-phase induction motor with a starting motor capacitor inserted in series with the startup winding, creating an LC circuit which produces a greater phase shift (and so, a much greater starting torque) than both split-phase and shaded pole motors. This motor has a ...
The revolving magnetic field produced with a two-phase system allowed electric motors to provide torque from zero motor speed, which was not possible with a single-phase induction motor (without an additional starting means). Induction motors designed for two-phase operation use a similar winding configuration as capacitor start single-phase ...
A three-phase induction motor has a simple design, inherently high starting torque and high efficiency. Such motors are applied in industry for many applications. A three-phase motor is more compact and less costly than a single-phase motor of the same voltage class and rating, and single-phase AC motors above 10 hp (7.5 kW) are uncommon. Three ...
Walter Bailys Polyphase motor (1879) marks the beginning of the development of modern polyphase motors. Mr. Mr. Bailey exhibited his invention on the Physical Society of London on June 28, 1879, on the occasion of his reading a paper entitled, "A Mode of Producing Arago's Rotations."
Discover the best free online games at AOL.com - Play board, card, casino, puzzle and many more online games while chatting with others in real-time.
A three-phase motor running on a single phase cannot start itself because it lacks the other phases to create a rotation on its own, much like a crank that is at dead center. A three-phase induction motor that is spinning under single-phase power applied to terminals L1 and L2 will generate an electric potential (voltage) across terminal L3 in ...