Amprobe PRM-6 [4375950] Phase Sequence and Motor Rotation Tester. The Amprobe PRM-6 Phase sequence and motor roation tester ensures that electrical equipment is correctly and safely connected. If you install or connect 3-phase motors and systems, you recognize the importance of verifying the correct motor rotation and wiring phase sequence. Improper connections can cause motors to rotate in reverse direction, potentially damaging the motor and the equipment it is powering. The PRM6 Motor and Phase Rotation Tester can test the motor rotation of 3-phase systems, and verify 3-phase receptacle wiring and phase sequencing with test leads. An additional advanced feature of the PRM-6 is wireless motor rotation detection, which senses motor rotation direction without use of test leads. This is particularly useful for fast-running motors when the motor rotation cannot be visually determined or when the drive shaft is not visible.