|Electrical Installation - Basic Vocational Knowledge|
|7. Mounting and connection of motors|
Prior to mounting electric motors it has to be checked, whether the motor will be suited for the connection in question and that the motor is not damaged.
The motor and the machine to be driven are to be exactly aligned. This holds also for transmission devices. Motors for connection to three-phase current up to a power of 2.2 kW are directly started. For starting the motor a multi-section rotary switch is employed to which a motor protection switch is series connected. The overcurrent release of the motor protection switch is to be set to the rated current of the motor.
Three-phase asynchronous motors with squirrel-cage of bigger power are switched on via a starting circuit. The mostly used starting arrangement is the star-delta connection.
In case of star connection of three-phase motors, bridges are being laid over the ends of the winding.
In case of delta connection bridges are connecting the opposite beginnings and ends of the winding.
If star-delta starting is to be employed, the bridges will have to be removed.