Function of a 3-phase-induction motor
In this video, we discuss the functioning of a 3 phase induction motor. From the content:
- How torque can be created
- The meaning of slip for the induction motor
- Current and torque characteristic curves
- Motor plate according to IEC
3-phase-induction motor plate - the most important informations (according to IEC 60034)
- Shaft power P in kW with a nominal load
- Power factor cos φ
- IP- International Protection , also called Ingress Protection, classifies and rates the degree of protection of casings and enclosures. and water by The IP code is indicated by 2 numbers: First number: Degree of protection provided against intrusion, second number: Protection against water.
- Nominal rotational speed
- Rated voltage and electrical connection. Here, the motor may be connected to delta at 400 V mains voltage.
- Phase current at nominal speed
- Rated frequency
- Insulation class - specifies the thermal resistance of the motor winding.
Work order: Calculate the necessary electrical power, the torque and the efficiency at nominal range from the specifications of the motor plate shown above!
Pelectr = √3 * U * I * cosφ = √3 * 400 V * 24 A * 0,79 = 13,136 kW
Pmech = T * n / 9550 => T = Pab * 9550 / n = 11 kW * 9550 / 1425 min-1 = 73,72 Nm
η = Pmechan / Pelectr = 11kW / 13,136 kW = 0,837