E66.01 fault in inovance IS580 drive indicates Braking resistor disconnected. This means the drive has detected the braking resistor is either not connected or there is an open circuit in the braking resistor circuit.

• Power off the drive & inspect brake resistor.
• Inspect cables, connectors, and terminals for disconnections or damage.
• It should match the specified value from the drive manual (typically several ohms, depending on your resistor).
• Replace the braking resistor if open circuit.
• Ensure correct connection to the braking resistor terminals on the drive.