The 4156 PR has three individual ranges for different applications.
1.In the PHASE ROTATION range, the meter is connected in the phase sequence circuit and the red terminals for phase rotation may be used to make a phase sequence measurement. The batteries are disconnected for the testing.
2.In the MOTOR range, the meter is disconnected from the phase sequence circuit and connected in the motor rotation circuit. The batteries are connected for the testing. The yellow terminals may now be used for a motor rotation test.
3.In the TRANSFORMER range, the meter and batteries are connected so that the yellow terminals can be used for a transformer polarity test. It is also designed for circuit continuity tests. Users can connect test leads to L1 and L2 terminals for continuity checking.