Electronic Bypass Controller Installation and Commissioning Guide
15
2.7.2 Check #2: Rotation on Bypass power
NOTE: This operation will start the motor across the line. Place the electronic
bypass in the Bypass Mode by pressing the BYPASS pushbutton on the electronic
bypass keypad. The BYPASS LED will light.
Press the HAND button on the electronic bypass keypad. This will start the motor
across the line. Check motor rotation.
Quickly stop the motor by pressing the OFF/RESET push button.
Note the direction of rotation as the motor shaft begins to rotate as compared to the
required rotation direction.
Change the appropriate leads as noted in the following table.
Motor Rotation Correction
VFD
Correct
Correct
Incorrect
Incorrect
Bypass Correct
Incorrect
Correct
Incorrect
Action. No Action. Change any
two power
leads at input
disconnect.
Change any
two leads at
input at input
disconnect,
and change
any two leads
at the output
of the motor
overload.
Change any
two leads
at output
of motor
overload.
There is no standard for the rotational direction of an induction motor based
on the motor lead markings. This, plus the uncertainty of the phase rotation
of the utility power being applied to the electronic bypass package terminals,
requires that the motor rotation direction be checked and be correct in both VFD
and Bypass Modes. Failure to confirm rotation may cause severe damage to the
electronic bypass package, motor or the driven equipment.
