DC Injection BrakingNOTICE: Excessive current during DC Injection Braking and excessive duration of DC Injection Braking can cause motor overheat.Acceleration/Deceleration TimesAcceleration and deceleration times are affected by the amount of torque generated by the motor, the load torque, and themoment of inertia. Set a longer accel/decel time when Stall Prevention is enabled. The accel/decel times are lengthened foras long as the Stall Prevention function is in operation. Install one of the available braking options or increase the capacity ofthe drive for faster acceleration and deceleration.n General HandlingWiring CheckNOTICE: Do not connect power supply lines to output terminals U/T1, V/T2, or W/T3. Failure to comply will destroy the drive. Be sure toperform a final check of all sequence wiring and other connections before turning on the power and also check for short circuits on thecontrol terminals, which may damage the drive.Inspection and MaintenanceWARNING! Electrical Shock Hazard. Capacitors in the drive do not immediately discharge after shutting off the power. Wait for at least theamount of time specified on the drive before touching any components after shutting off the power. Failure to comply may cause injury topersonnel from electrical shock.Transporting the DriveNOTICE: Never steam clean the drive. During transport, keep the drive from coming into contact with salts, fluorine, bromine, phthalateester, and other such harmful chemicals.u Motor Application PrecautionsInsulation ToleranceNOTICE: Consider motor voltage tolerance levels and motor insulation in applications with an input voltage of over 480 V or particularlylong wiring distances.High-Speed OperationNOTICE: Problems may occur with the motor bearings and dynamic balance of the machine when operating a motor beyond its rated speed.Contact the motor or machine manufacturer.Torque CharacteristicsTorque characteristics differ compared to operating the motor directly from line power. The user should have a fullunderstanding of the load torque characteristics for the application.Vibration and ShockThe drive allows selection of high carrier PWM control and low carrier PWM. Selecting high carrier PWM can help reducemotor oscillation.Take particular caution when adding a variable speed drive to an application running a motor from line power at a constantspeed. If resonance occurs, install shock-absorbing isolation mounts around the base of the motor and enable the Jumpfrequency selection to prevent continuous operation in the resonant frequency range.Audible NoiseThe audible noise of the motor varies based on the carrier frequency setting. However, drive current derating may be required.When using a high carrier frequency, audible noise from the motor is comparable to the motor noise generated when runningfrom line power.Specialized MotorsMulti-Pole MotorThe rated current of a multi-pole motor differs from that of a standard motor, so be sure to check the maximum current whenselecting a drive. Always stop the motor before switching between the number of motor poles. The motor will coast to stop ifa regenerative overvoltage (ov) fault occurs or if overcurrent (oC) protection is triggered.Submersible MotorThe rated current of a submersible motor is greater than that of a standard motor, so select the drive accordingly. Use a motorcable large enough to avoid decreasing the maximum torque level from voltage drop caused by a long motor cable.Explosion-Proof MotorThe motor and the drive must be tested together to be certified as explosion-proof. The drive is not designed for explosion-proof areas.i.2 General SafetyYASKAWA ELECTRIC SIEP YAIZ1B 01E YASKAWA AC Drive – Z1000 Bypass Technical Manual 19
