Extech Phase Rotation Testers series

Phase Rotation Testers series

Extech Phase Rotation Testers series
Extech’s complete line of 3-phase testers ranges from a basic stand alone unit to a multimeter with built-in phase indicator
Phase Rotation Testers determine the phase rotation of energized circuits and the rotation of motors.
Phase Rotation Testers have two primary functions. Both are necessary to ensure that a motor will rotate in a prescribed direction when energized.
Determine the rotation direction of motors, clockwise or anticlockwise/counterclockwise, before connecting line voltage. Running motors backwards/wrong direction may damage expensive machinery. In these cases, motors are tested on a bench or temporary power is run to uncoupled motors for a rotation test. This can be costly, time-consuming, and hazardous, especially with high voltage motors. Using a motor and phase rotation tester, an electrician can make the final motor connections on the first attempt.
Determine phase rotation or sequence of energized power circuits. The load side (i.e. unpowered motor) and also the supply side should be checked. The phases of the line voltage must also be properly identified so that they can be connected to the motor for the desired rotation. This is true in a new or replacement motor situation, but also when working on switchgear, such as transformers, disconnects, and breakers. Utility crews or plant personnel working on switchgear must correctly connect or the result might be many backward rotating motors at different locations when power is re-applied. This can be very dangerous, plus possibly damage equipment.
Additional uses for Phase Sequence and Motor Rotation Testers
  • Identifying polarity and phase of motor windings where the terminal markings have been destroyed or where connection diagrams are lost
  • Determine polarity of instrument and power transformers
  • Continuity tester in checking electrical circuits


Extech Phase Rotation Testers series

Extech 480400


Extech 480403


Extech PRT200


Extech MA640-K


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