Capacitor motor, 0.3

In this equipment set, the operation and stationary operating behaviour of an electrical capacitor motor with squirrel-cage rotor are investigated. The experiments focus particularly on connection, rated values, efficiency determination and the machine characteristic curve.

The experiments are performed with industrially manufactured machines. All test machines are equipped with a special base for connection to the Machine Testing System 0.3. With the Machine Test CASSY, all measured values of the AC machines are recorded. The measured values can be displayed directly on the integrated display as a single value, as a table of a measurement series, or as a diagram. The measurements can be carried out without additional software, and the measurement data can be stored locally on the device. The machines are supplied via a variable transformer or directly from the mains.

Learning objectives

• Protective measures and electrical safety
• Setting up electrical machines and putting them into operation
• Use of starting circuits
• Efficiency of the machine
• Assessment of electrical machine characteristics

Capacitor motors are rotating-field machines with squirrel-cage rotor that are operated with single-phase alternating current. The rotating field is elliptical and is generated by a 2-strand stator winding. The main winding of the stator is connected directly to the mains voltage; the spatially offset auxiliary winding receives the supply voltage via a capacitor connected in series. In order to increase the starting torque, a starting capacitor is connected in parallel to the operating capacitor via a relay.

Highlights

• In order to protect against overheating, the stator windings of the test machines are equipped with temperature detectors.
• In case of overheating, the machine testing system switches off the load of the test machine, thus a preserved air cooling. This prevents damage to the testing machines.
• The test machines are equipped with an educationally designed terminal board with the winding configuration printed on it.
• The ends of all the windings are led out at the terminal board at safety sockets (4 mm).
• Computer-supported acquisition of measurement data provides for meaningful measurement results.
• The arrangement of the 4 mm safety sockets corresponds to the standards for industrial machines.

Measuring and media system

Machine Test CASSY

The Machine Test CASSY 0.3 can be quickly operated in all functions directly via the display, the rotary knob and the buttons on the device. All settings and measurement results can be saved on the device and quickly called up again later or simply downloaded.

In addition, the Machine Test CASSY 0.3 system can be fully controlled in real time via the RJ45 Ethernet, W-LAN and USB-C interfaces.

These interfaces can be used by the following software:

• CASSY Lab 2 for drive and energy technology,
• MATLAB and LabVIEW,
• Lab Docs Editor Advanced.

The following integrated servers are available in the Machine Test CASSY 0.3 for the local media connection of at least four end devices simultaneously.

Further information can be found in the product documentation 7731901 Machine Test CASSY 0.3.

Target group

The target group is made up of commercial apprentices and students of electrical machine construction. The course offers experiments at an intermediate level for vocational schools and at the same time allows for the necessary insight into machine behaviour for scientific interpretation at bachelor level. The media connection makes the experiments suitable for demonstration in the classroom or a lecture hall.

The following equipment sets include further extended experiments with capacitor motors.

• E2.2.3.1 Universal motor AC