i.2 General SafetyYASKAWA ELECTRIC SIEP C710616 27C YASKAWA AC Drive A1000 Technical Manual 21■ General HandlingWiring CheckNever connect the power supply lines to output terminals U/T1, V/T2, or W/T3. Doing so will destroy the drive. Be sureto perform a final check of all sequence wiring and other connections before turning the power on. Make sure there areno short circuits on the control terminals (+V, AC, etc.), as this could damage the drive.Selecting a Circuit Breaker or Leakage Circuit BreakerYaskawa recommends installing Earth Leakage Circuit Breaker (ELCB) to the power supply side. The ELCB should bedesigned for use with an AC drive (e.g. Type B according to IEC 60755).Select a MCCB (Molded Case Circuit Breaker) or ELCB with a rated current that is 1.5 to 2 times higher than the ratedcurrent of the drive in order to avoid nuisance trips caused by harmonics in the drive input current. Also refer toInstalling a Molded Case Circuit Breaker (MCCB) on page 381.Magnetic Contactor InstallationUse a magnetic contactor (MC) to ensure that power to the drive can be completely shut off when necessary. The MCshould be wired so that it opens when a fault output terminal is triggered.Avoid switching a magnetic contactor on the power supply side more frequently than once every 30 minutes. Frequentswitching can cause damage to the drive.Inspection and MaintenanceCapacitors in the drive take time to discharge even after the power has been shut off. After shutting off the power, waitfor at least the amount of time specified on the drive before touching any components.The heatsink can become quite hot during operation, and proper precautions should be taken to prevent burns. Whenreplacing the cooling fan, shut off the power and wait at least 15 minutes to be sure that the heatsink has cooled down.Even when the power has been shut off for a drive running a PM motor, voltage continues to be generated at the motorterminals while the motor coasts to stop. Take the precautions described below to prevent shock and injury:• In Applications where the machine can still rotate even though the drive has fully stopped a load switch fordisconnecting motor and drive should be installed to the output side of the drive.• Do not allow an external force to rotate the motor beyond the maximum allowable speed, also when the drive has beenshut off.• Wait for at least the time specified on the warning label after opening the load switch on the output side beforeinspecting the drive or performing any maintenance.• Do not open and close the load switch while the motor is running, as this can damage the drive.• If the motor is coasting, make sure the power to the drive is turned on and the drive output has completely stoppedbefore closing the load switch.WiringAll wire ends should use ring terminals for UL/cUL compliance. Use only the tools recommended by the terminalmanufacturer for crimping.Transporting the DriveNever steam clean the drive.During transport, keep the drive from coming into contact with salts, fluorine, bromine, phthalate ester, and other suchharmful chemicals.◆ Notes on Motor Operation■ Using a Standard MotorLow Speed RangeThe cooling fan of a standard motor is usually designed to sufficiently cool the motor at the rated speed. As the self-cooling capability of such a motor reduces with the speed, applying full torque at low speed will possibly damage themotor. To prevent motor damage from overheat, reduce the load torque as the motor slows.
