Technical Specifications

FAQ

1. What is the continuous output current of the Allen Bradley 20BH140A0ANNANC0?

The 20BH140A0ANNANC0 provides a continuous output current of 140 A. Its normal-duty rating is 75 HP, while the heavy-duty rating is 55 HP. The drive can deliver 158 A for one minute and 190 A for three seconds under the specified overload conditions.

For proper drive selection, the motor nameplate current should be compared directly with the drive’s output current rating. Motor horsepower alone is not enough, particularly for applications with high starting torque, frequent acceleration, heavy loads, or repeated overload conditions.

2. What type of input power does the 20BH140A0ANNANC0 require?

The 20BH140A0ANNANC0 is designed for a 540 VDC, three-phase input and does not include a precharge circuit. The rated input current is 159 A at 540 VDC.

Because this is a DC-input PowerFlex 700 configuration, the external DC supply must be correctly matched to the drive. Before energizing the system, technicians should verify DC voltage, polarity, grounding, upstream protection, and cable connections. Incorrect DC input conditions can cause serious damage to the power section or result in immediate drive protection.

3. Which motor control methods are available on the 20BH140A0ANNANC0?

The 20BH140A0ANNANC0 supports vector-based motor control and V/Hz control. Sensorless vector control allows the drive to control motor speed and torque without requiring a standard encoder, making it suitable for many industrial applications.

During commissioning, accurate motor nameplate data should be entered, including rated voltage, current, frequency, speed, and power. Incorrect motor parameters can cause excessive current, unstable operation, poor torque response, or difficulty during startup.

For applications requiring precise low-speed torque or synchronized operation, the need for an encoder feedback option should be evaluated separately.

4. Does the 20BH140A0ANNANC0 include a brake IGBT or internal brake resistor?

No. This configuration is supplied without a brake IGBT and without an internal drive-mounted brake resistor.

During deceleration, a high-inertia motor can return regenerative energy to the DC bus. If the DC bus voltage rises beyond the allowable level, the drive may trip on overvoltage. This is particularly important for applications such as hoists, centrifuges, large conveyors, and winding machinery.

If rapid or frequent deceleration is required, the braking requirements should be evaluated during system design. An external braking or regenerative energy solution may be necessary depending on the load inertia and stopping requirements.

5. Does the 20BH140A0ANNANC0 support encoder feedback?

The standard configuration does not include feedback. Sensorless vector control can therefore be used without an external encoder for many general-purpose motor applications.

If the machine requires accurate low-speed operation, closed-loop speed control, synchronization, or precise torque control, an appropriate encoder feedback option may be considered. The PowerFlex 700 platform supports incremental dual-channel encoder applications when the corresponding hardware is installed.

For drive replacement projects, the existing machine should be checked carefully for encoder usage. Removing feedback from a system that previously relied on closed-loop control can affect speed accuracy and low-speed performance.

6. How can the 20BH140A0ANNANC0 be connected to a PLC or DCS?

The drive provides two analog inputs, two analog outputs, six digital inputs, and three digital outputs for integration with PLC, DCS, HMI, and other industrial control systems.

Digital inputs can be used for commands such as start, stop, enable, and direction. Analog inputs can receive speed references or other process signals, while digital and analog outputs can provide running status, fault information, frequency feedback, or other operating data.

The standard configuration does not include an internal communication module. If network-based control is required, a compatible communication option should be selected according to the PLC or DCS architecture and required communication protocol.

7. What should be checked if the 20BH140A0ANNANC0 trips on overcurrent?

First determine when the overcurrent occurs. If it happens immediately during startup, check the motor parameters, motor wiring, output terminals, and mechanical load. A seized motor, excessive friction, or mechanical blockage can cause the current to rise rapidly.

If the fault occurs during acceleration, check whether the acceleration time is too short for the connected load. High-inertia equipment may require a longer acceleration period to prevent excessive current demand.

For faults during normal operation, inspect the driven machinery for sudden load increases, mechanical binding, bearing problems, or transmission issues. The motor cable should also be checked for phase-to-phase faults, insulation problems, or loose connections.

The programmable current limit can be set from approximately 20% to 160% of rated output current, while the instantaneous current limit is approximately 220–300% of rated current depending on the drive rating.

8. How should the acceleration and deceleration times be configured?

The 20BH140A0ANNANC0 provides independently programmable acceleration and deceleration times from 0 to 3600 seconds, with settings available in 0.1-second increments.

If the acceleration time is too short, the motor may require excessive torque and current, potentially causing an overcurrent trip. If the deceleration time is too short, regenerative energy can raise the DC bus voltage and cause an overvoltage fault.

During commissioning, it is best to begin with conservative acceleration and deceleration settings and then optimize them based on actual motor current, load behavior, stopping requirements, and machine response. For high-inertia equipment, particular attention should be paid to the energy generated during deceleration.