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close this bookElectrical Machines - Basic vocational knowledge (Institut für Berufliche Entwicklung, 144 p.)
close this folder7. Single-phase alternating current motors
close this folder7.2. Three-phase asynchronous motor in single-phase operation (capacitor motor)
View the document7.2.1. Assembly and operating principle
View the document7.2.2. Operational behaviour

7.2.2. Operational behaviour

Initial torque is only some 30 per cent of rated torque. Consequently, in some cases it becomes necessary to parallel switch a starting capacitor of approx. 150 F/kW to the operating capacitor. However, because of its excessive current acceptance after starting, this operating capacitor should be switched off, for example by means of a centrifugal switch.

The magnitude of the operating capacitor must be selected in accordance with a motor power of some 70 F/kW and in line with voltage level.