Inverter Application Precautions
Selection
Observe the following precautions when selecting an Inverter.
Installing Reactors
A large peak current can flow in the power input circuit when the Inverter is connected to a large-capacity power transformer (600 kVA or higher) or when switching a phase shifting capacitor. Excessive peak current can destroy the converter section. To prevent this, install a DC or AC reactor to improve the power supply power factor.
If a thyristor converter, such as a DC drive, is connected in the same power supply system, connect a DC or
AC reactor regardless of the power supply conditions shown in the following diagram.
Power supply
(kVA)
DC or AC reactor required
DC or AC reactor not required
Inverter capacity (kVA)
Installation
Observe the following precautions when installing an Inverter.
Installation in Enclosures
Install the Inverter in a clean location where it is not subjected to oil mist, dust, and other contaminants, or install the Inverter in a completely enclosed panel. Provide cooling measures and sufficient panel space so that the temperature surrounding the Inverter does not exceed the allowable temperature. Do not install the Inverter on wood or other combustible materials.
Installation Direction
Mount the Inverter vertically to a wall or other vertical surface.
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Settings
Observe the following precautions when making settings for an Inverter.
Upper Limits
The maximum output frequency can be set up to 120Hz. Setting the output frequency too high can damage the machine. So pay attention to the mechanical system and observe required limits for the output frequency.
DC Injection Braking
If the DC Injection Braking Current or the Braking Time are set too high the motor can overheat what can damage the motor
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Acceleration/Deceleration Times
The motor's acceleration and deceleration times are determined by the torque generated by the motor, the load torque, and the load's inertial moment (GD
2
/4). If the stall prevention functions are activated during acceleration or deceleration, it might be necessary to increase the acceleration or deceleration time.
To reduce the acceleration or deceleration times, increase the capacity of the motor and Inverter.
Handling
Observe the following precautions during wiring or maintenance of an Inverter.
Wiring Check
The Inverter will be internally damaged if the power supply voltage is applied to output terminal U, V, or W.
Check wiring for any mistakes before supplying power. Check all wiring and control sequences carefully.
Magnetic Contactor Installation
If a magnetic contactor is installed in the power supply line, do not exceed one start per hour. Switching more often can damage the inrush current prevention circuit.
Maintenance and Inspections
After turning OFF the main circuit power supply it can take several minutes before the DC bus is discharged completely. The CHARGE LED, indicating if the DC bus is charged, glows above a voltage of 10VDC.
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