i.2 General SafetyYASKAWA ELECTRIC SIEP C710616 27G YASKAWA AC Drive A1000 Technical Manual 21 Application Notes SelectionInstalling a ReactorAn AC or DC reactor can be used for the following:• to suppress harmonic current.• to smooth peak current that results from capacitor switching.• when the power supply is above 600 kVA.• when the drive is running from a power supply system with thyristor converters.Note: A DC reactor is built in to the drive models 2A0110 to 2A0415 and 4A0058 to 4A1200.Figure i.1Figure i.1 Installing a ReactorDrive CapacityFor specialized motors, make sure that the motor rated current is less than rated output current for the drive. Whenrunning more than one motor in parallel from a single drive, the capacity of the drive should be larger than 1.1 times ofthe total motor rated current.Starting TorqueThe overload rating for the drive determines the starting and accelerating characteristics of the motor. Expect lowertorque than when running from line power. To get more starting torque, use a larger drive or increase both the motor anddrive capacity.Emergency StopWhen the drive faults out, the output is shut off. This, however, does not stop the motor immediately. Some type ofmechanical brake may be needed if it is necessary to halt the motor faster than the Fast Stop function is able to.OptionsThe B1, B2, -, +1, +2, and +3 terminals are used to connect optional devices. Connect only A1000-compatible devices.Repetitive Starting/StoppingCranes (hoists), elevators, punching presses, and other such applications with frequent starts and stops often exceed150% of their rated current values. Heat stress generated from repetitive high current can shorten the life span of theIGBTs. The expected lifesaving for the IGBTs is about 8 million start and stop cycles with a 2 kHz carrier frequency anda 150% peak current.YASKAWA recommends lowering the carrier frequency, particularly when audible noise is not a concern. The user canalso choose to reduce the load, increase the acceleration and deceleration times, or switch to a larger drive. This will helpkeep peak current levels under 150%. Be sure to check the peak current levels when starting and stopping repeatedlyduring the initial test run, and make adjustments accordingly.For crane-type applications using an inching function in which the motor is quickly started and stopped, YASKAWArecommends the following to ensure motor torque levels:• Select a large enough drive so that peak current levels remain below 150% of the drive rated current.• The drive should be one frame size larger than the motor.40006000 60 400Drive Capacity (kVA)Power SupplyCapacity (kVA)Power supply harmonicsreactor requiredReactorunnecessary
