Technical Specifications

FAQ

1. What type of power input does the 20BH875N0NNNNNC0 use?

The 20BH875N0NNNNNC0 is designed for a 540 VDC input system. It uses a DC bus input rather than a conventional three-phase AC input configuration. The external DC power system should therefore be designed with suitable disconnecting equipment, protection devices, bus connections, and current-handling capacity. Because the drive operates with a high-energy DC bus, installation and maintenance procedures should include proper electrical isolation and DC bus discharge verification before service work is performed.

2. What are the continuous and overload current ratings of the 20BH875N0NNNNNC0?

The continuous output current rating is 875 A. The drive can provide 963 A for one minute and 1313 A for three seconds under the specified operating conditions. These overload capabilities allow the drive to handle short-duration increases in motor torque demand, such as acceleration or temporary load changes. The continuous motor current should remain within the appropriate drive rating, while the short-term overload capacity should only be used according to the application duty cycle and operating conditions.

3. What is the power rating of the 20BH875N0NNNNNC0?

The 20BH875N0NNNNNC0 provides a normal-duty power rating of 500 kW and a heavy-duty power rating of 400 kW. The applicable rating depends on the motor load profile, operating duty, and required overload capability. For correct selection, the motor’s rated current should be compared with the drive’s continuous output current, while starting torque, acceleration requirements, load inertia, and operating cycle should also be considered. Selecting the drive only according to motor power may result in an unsuitable configuration for demanding applications.

4. What does the “No Precharge” configuration mean for this drive?

The “No Precharge” configuration indicates that this version does not use an internal precharge arrangement in the same manner as configurations equipped with a precharge circuit. Since the drive is connected to a high-current DC supply, the external DC power system must provide suitable power switching, protection, and current-management provisions. The DC bus connection sequence should be carefully controlled during installation and commissioning. Proper procedures are particularly important because the DC bus can retain hazardous electrical energy even after the incoming power source has been disconnected.

5. What should be considered when selecting a motor for the 20BH875N0NNNNNC0?

Motor selection should consider rated voltage, rated current, power, frequency, speed range, torque requirements, duty cycle, and the characteristics of the driven machine. The drive’s 875 A continuous output capability provides substantial capacity for large industrial motors, but the selected motor must remain within the applicable current and operating limits. Applications such as large conveyors, pumps, fans, compressors, process machinery, and high-inertia equipment may require different acceleration and torque characteristics. Accurate motor nameplate information should be entered during commissioning to ensure appropriate drive control.

6. What control functions are suitable for high-power applications using this drive?

The PowerFlex 700 platform supports adjustable-frequency motor control and vector-based control functions for applications requiring controlled motor speed and torque. Vector control can provide improved torque response and speed regulation when the load changes during operation. For high-power equipment, the control parameters should be configured according to the motor and mechanical load characteristics. Acceleration and deceleration times, current limits, minimum and maximum operating frequency, stopping method, and other application-specific parameters should be checked before the drive is operated at full load.

7. What should be checked if the drive produces an overcurrent fault during acceleration?

If an overcurrent fault occurs during acceleration, the motor, driven equipment, wiring, and drive parameters should all be checked. Mechanical blockage, excessive friction, excessive load inertia, or a sudden increase in load can cause the motor to demand more current than expected. The motor cables should also be inspected for phase-to-phase shorts, ground faults, damaged insulation, or incorrect connections. Motor voltage, rated current, frequency, and other configuration parameters should be verified. If the acceleration ramp is too short for the mechanical load, increasing the acceleration time can reduce the instantaneous current demand and provide smoother motor acceleration.

8. What maintenance points are important for the 20BH875N0NNNNNC0?

Maintenance should focus on the cooling system, electrical connections, power components, DC bus system, and control electronics. Forced-air cooling paths should be kept clean to maintain adequate heat dissipation. Power terminals and electrical connections should be inspected for looseness, overheating, discoloration, or insulation damage. The DC bus and associated protection equipment should also be checked according to the maintenance schedule. Before internal inspection or service, the DC power supply must be isolated and the stored DC bus energy must be discharged and verified according to the applicable safety procedure. Reviewing fault history can also help identify recurring overcurrent, overvoltage, or thermal conditions before they develop into more serious equipment problems.