Encoder Phase A/B Swap

What does 7302 mean?

The pulse encoder phasing is incorrect, specifically Phase A is connected to the terminal for Phase B and vice versa. This wiring error will cause the drive to misinterpret motor direction and speed, leading to incorrect motor operation, instability, or immediate trips.

• Encoder A and B phase signal wires (e.g., terminals X1, X2) are physically swapped at the drive's encoder input terminal block.
• Encoder A and B phase signal wires are physically swapped at the encoder's connector or terminal box.
• Incorrect wiring drawing followed during initial installation, leading to the A/B swap.
• Drive parameter (e.g., P3-02) for encoder direction or phase order is incorrectly configured, reversing the expected logic.
• Damaged encoder input circuit on the drive's control board, misinterpreting the phase order.

Click steps to track your progress.

1. 1

   1. De-energize and lock out power, then physically swap the encoder A and B phase wires (e.g., terminals X1 and X2) at the drive's encoder input terminals.

2. 2

   2. Alternatively, if physical swap is difficult, check if a parameter (e.g., P3-02) exists in the drive to electronically reverse encoder direction or phase order.

3. 3

   3. Verify the wiring diagram for the specific encoder and drive model to confirm correct A and B phase connections.

4. 4

   4. Rotate the motor manually and observe the drive's reported speed and direction feedback (e.g., P3-03) after correcting the phase order.

5. 5

   5. Check for correct connection of the complementary signals (A_not, B_not) as swapping these without swapping A and B will also cause issues.