The fault code 64B1 in your ABB ACS880 drive indicates an internal SSW fault. SSW stands for "Safe Stop Workplace." This fault signifies an issue within the drive's internal circuitry related to the Safe Stop function.

Possible Causes of Internal SSW Fault:

The 64B1 fault suggests a malfunction within the internal hardware or software components responsible for the Safe Stop function. Here are some possibilities:

• Faulty Hardware: Components within the drive's circuitry related to Safe Stop might have malfunctioned.
• Software Glitch: Less likely, but a glitch in the drive's software managing the Safe Stop function could be responsible.