Search results
Results from the WOW.Com Content Network
Simplified single line diagram of a single-phase transfer switch to select either 'city' (utility) power or local generator power 3-phase Intelligent transfer switch. A transfer switch is an electrical switch that switches a load between two sources. Some transfer switches are manual, in that an operator effects the transfer by throwing a ...
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-phase motors also vibrate less and hence last longer than single-phase motors of the same power used under the same conditions. [32]
In Europe, three-phase 230/400 V is most commonly used. However, 130/225 V, three-wire, two-phase electric power discontinued systems called B1 are used to run old installations in small groups of houses when only two of the three-phase high-voltage conductors are used. The phase shift in Europe is 120°, as is the case with three-phase current.