The rotor of a squirrel-cage motor. This is why we call this type of connection "Star" or Y. A star connection is accomplished simply by bridging one horizontal row in the connection box. This is a photo from the connection box of a motor connected in Star. A Delta connection is easily accomplished by bridging the 3 columns in the connection box vertically. This is a photo from the connection box of a motor connected in Delta.
Testing a three-phase electric motor without a trip down to the repair shop requires a cautious approach, but happily all you need to start with is a volt-ohmmeter and some simple hand tools. More advanced testing requires specialized tools. Those are described below. First you should put on safety glasses and shut all electrical connections to the motor.
Electrical motor is the common used in industry all over the world. It very important device to made production smoothly. To ensure the electrical motor condition is good or not,we must know how to testing it. The electrician or maintenance person must have this skill to determine the electrical motor condition,defected or cannot use anymore.
Single-phase motors have two windings, a start winding and a run winding. Measuring winding resistance is a power-off check. Power must be disconnected and locked out. Starting with 2-wire motors, winding resistance is measured between the two black motor leads. This can be done at the motor, at the well head, or even at the pressure switch.