EL
ErrorLib
Brands
||
  1. Home
  2. Allen-Bradley
  3. PowerFlex 750
  4. 28
About·Privacy·Terms

ErrorLib — Industrial Fault Code Library

Disclaimer: ErrorLib is an independent technical reference tool. While we aim for accuracy, always verify with the manufacturer’s official service manuals before performing maintenance on industrial equipment. ErrorLib is not affiliated with the brands listed.

28

TP Encls Config

Allen-Bradley · PowerFlex 750

What does 28 mean?

This Alarm 2 indicates that Encoderless TorqProve has been enabled, but the specific application concerns, limitations, and risks associated with operating TorqProve without an encoder have not been reviewed or acknowledged. The drive cannot start due to this unaddressed configuration risk. It is crucial to understand these limitations to ensure safe operation.

Common Causes

  • P1100 (Torque Prove Mode) is set to an encoderless option (e.g., '1' for Sensorless Torque Prove) without acknowledging risks.
  • P35 (Speed Feedback Select) is configured for sensorless vector control (e.g., '0' or 'Sensorless') while TorqProve is active.
  • Torque control accuracy requirements for the application exceed the capabilities of encoderless operation.
  • Safety function configuration parameter P1101 (Torq Prv Safety Ack) has not been explicitly set to acknowledge encoderless limitations.

Repair Steps & Checklist

Click steps to track your progress.

  1. 1

    1. Access the drive HMI or programming software and navigate to P1100 (Torque Prove Mode).

  2. 2

    2. If encoderless operation is desired for the application, set P1101 (Torq Prv Safety Ack) to '1' (Acknowledged) to confirm understanding of risks.

  3. 3

    3. If an encoder is available and desired for improved accuracy, reconfigure P35 (Speed Feedback Select) to the appropriate encoder input (e.g., '1').

  4. 4

    4. Review the application's safety integrity level (SIL) and ensure that encoderless TorqProve meets these specific requirements.

  5. 5

    5. Test the TorqProve functionality with a controlled load and monitor actual torque values (e.g., A0-07) to verify proper operation and fault clearance.

Browse all codes in this manual (60)
Verified technical data. Last updated: April 2026

Related Faults

100Parameter Chksum101PwrDn NVS Blank10132I1 Incompat PS
Source: Allen-Bradley PowerFlex 750
View Official PDFSearch more codes in this manual