Technical Specifications

FAQ

1. What is the rated output current of the Allen-Bradley 20DC085A0ENNANANE?
The Allen-Bradley 20DC085A0ENNANANE PowerFlex 700S AC Drive has a continuous output current rating of 85 A. It is rated for 45 kW under normal-duty operation and 37 kW under heavy-duty operation at a 400 V AC, three-phase input. The drive can provide approximately 94 A for one minute and 144 A for three seconds under the specified overload conditions. When selecting a motor, the actual motor full-load current and duty cycle should be compared with these ratings rather than selecting the drive only according to motor horsepower.

2. What type of motor control does the 20DC085A0ENNANANE support?
The PowerFlex 700S uses Phase II control and supports field-oriented motor control with or without feedback. It can also be configured for permanent magnet motor applications. Compared with basic V/Hz control, field-oriented control provides more precise management of motor flux and torque, making it suitable for applications requiring improved speed regulation and dynamic response. Correct motor parameter setup is important during commissioning, particularly when operating without encoder feedback or when precise torque performance is required.

3. Does the 20DC085A0ENNANANE have an internal braking resistor?
No. This configuration does not include an internal brake IGBT or drive-mounted braking resistor. During rapid deceleration, the connected motor can return regenerative energy to the DC bus. If the regenerated energy causes the DC-bus voltage to exceed the allowable limit, the drive can generate an overvoltage fault. For high-inertia loads, frequent stopping, or short deceleration cycles, the application should therefore be evaluated for an external braking solution. Increasing the deceleration time can also reduce the amount of regenerative energy returned to the drive.

4. Can the 20DC085A0ENNANANE be connected to a PLC or DCS system?
Yes. The drive provides six digital inputs, two digital outputs, three analog inputs, and two analog outputs for hardwired integration with PLC, DCS, motion-control, and other industrial automation systems. This particular catalog configuration does not include an internal communication module, so network-based integration requires the appropriate external communication hardware or system architecture. During PLC or DCS integration, it is good practice to exchange not only run and speed commands but also drive status, fault information, current, frequency, and other diagnostic data to improve system-level monitoring.

5. What should be checked when the 20DC085A0ENNANANE trips on overcurrent?
Overcurrent troubleshooting should begin with the motor and mechanical load. Check for a locked rotor, excessive friction, mechanical obstruction, damaged bearings, or a sudden increase in load torque. Next, inspect the motor cable for phase-to-phase shorts, ground faults, insulation damage, and incorrect phase connections. If the fault occurs mainly during acceleration, verify whether the programmed acceleration time is too short for the machine inertia. Motor nameplate parameters should also be checked, including rated voltage, current, frequency, and speed. For field-oriented control, incorrect motor parameters or incomplete tuning can also cause unstable current behavior.

6. How should a DC-bus overvoltage fault be diagnosed on this PowerFlex 700S drive?
The first step is to determine when the overvoltage occurs. If it happens during deceleration, the most likely cause is regenerative energy from the motor and driven load. Check the deceleration time, load inertia, stopping frequency, and operating cycle. The PowerFlex 700S configuration does not include an internal braking resistor, so rapid deceleration may require an external braking arrangement. The drive’s DC-bus overvoltage trip level is approximately 810 V DC for the 380/400 V input configuration. Input voltage should also be checked because an excessively high line voltage can reduce the available operating margin.

7. What is the maximum output frequency of the 20DC085A0ENNANANE?
The maximum output frequency is 400 Hz. However, the drive’s maximum frequency should not automatically be used as the motor’s permissible operating frequency. When operating above the motor’s base frequency, the motor’s maximum mechanical speed, bearing limits, rotor balance, cooling performance, and insulation requirements must be evaluated. The driven machine must also be checked for critical speeds and mechanical resonance. For high-speed applications, the final maximum-frequency setting should therefore be established from the motor and machine manufacturer’s operating limits.

8. What are the key commissioning checks for the 20DC085A0ENNANANE?
Before commissioning, verify the 400 V AC three-phase supply, grounding, protective devices, motor wiring, control wiring, and encoder connections where feedback is used. Confirm that the motor current is compatible with the drive’s 85 A continuous rating and enter the motor nameplate information accurately. If an incremental encoder is installed, verify the encoder supply voltage, signal wiring, polarity, pulse feedback, and scaling parameters. During the initial run, start at low speed and confirm motor direction, output current, acceleration, deceleration, and feedback behavior. If faults occur, use the drive diagnostic information together with motor parameters, load conditions, current limits, and acceleration/deceleration settings to isolate the cause.