E66.02 fault in inovance IS580 drive indicates "Braking resistor resistance smaller than minimum". This means the drive has detected that the resistance of the connected braking resistor is too low, potentially causing excessive current flow when the braking IGBT activates.

• Compare the installed resistor's resistance (in ohms) against the minimum allowed in the IS580 manual for your motor/drive rating.
• Use a multimeter to measure resistance across the resistor terminals (with drive powered off).
• If it's lower than recommended, replace it with a properly rated resistor (resistance and power rating).