E49.02 fault in inovance IS580 drive indicates Speed sensor interfered. This means the drive is detecting abnormal or unstable signals from the speed sensor — likely due to electrical interference, signal noise, or inconsistent pulse feedback. It means the sensor is connected, but the feedback is noisy, distorted, or unreliable.

• Check for loose connectors, broken wires, or damaged cables.
• Make sure the encoder/resolver cable is shielded.
• The shield should be grounded at one point only (preferably at the drive side).