n Motor Rotates in the Opposite Direction from the Run CommandCause Possible SolutionsPhase wiring between the drive and motor is incorrect.• Check the motor wiring.• Switch two motor cables (U, V, and W) to reverse motor direction.• Connect drive output terminals U/T1, V/T2, and W/T3 in the right order to match motorterminals U, V, and W.• Change the setting of parameter b1-14.The forward direction for the motor is set up incorrectly.Typically, forward is designated as being counterclockwise when looking from the motor shaft(see figure below).121. Forward Rotating Motor (looking down the motor shaft)2. Motor ShaftThe motor is running at almost 0 Hz and the SpeedSearch estimated the speed to be in the oppositedirection.• Disable bi-directional search (b3-14 = 0) so that Speed Search is performed only in thespecified direction.Note: Check the motor specifications for the forward and reverse directions. The motor specifications will vary depending on the manufacturerof the motor.n Motor Rotates in One Direction OnlyCause Possible SolutionsThe drive prohibits reverse rotation. • Check parameter b1-04.• Set parameter b1-04 to 0 to allow the motor to rotate in reverse.u Motor is Too HotCause Possible SolutionsThe load is too heavy.If the load is too heavy for the motor, the motor will overheat as it exceeds its rated torque valuefor an extended period of time.Keep in mind that the motor also has a short-term overload rating in addition to the possiblesolutions provided below:• Reduce the load.• Increase the acceleration and deceleration times.• Check the values set for the motor protection (L1-01, L1-02) as well as the motor rated current(E2-01).• Increase motor capacity.The air around the motor is too hot. • Check the ambient temperature.• Cool the area until it is within the specified temperature range.Insufficient voltage insulation between motor phases.When the motor cable is long, high voltage surges occur between the motor coils and driveswitching.Normally, surges can reach up to three times the drive input power supply voltage.• Use a motor with a voltage tolerance higher than the max voltage surge.• Use an inverter-duty motor rated for use with AC drives when using the motor on drives ratedhigher than 208 V.• Install an AC reactor on the output side of the drive. The carrier frequency should be set to 2kHz when installing an AC reactor.The motor fan has stopped or is clogged. Check the motor fan.The carrier frequency is too low. Increase the carrier frequency to lower the current harmonic distortion and lower the motortemperature.6.9 Troubleshooting without Fault Display260 YASKAWA ELECTRIC SIEP YAIZ1B 01E YASKAWA AC Drive – Z1000 Bypass Technical Manual
