DC Bus Fuse Open

What does PUF mean?

The Drive detects that the DC bus fuse has opened. This is typically caused by shorted output transistor(s) or output terminals, indicating a severe internal fault in the power circuit. The fuse opens to protect upstream components but requires addressing the underlying short.

Additional Steps

Steps 1–2 are listed in Priority Fix.

1. 3

   Perform internal checks (referencing Table 6.6, if available, or standard procedures) without power to identify shorted components.

2. 4

   Replace any identified shorted component(s), such as output transistors.

3. 5

   Replace the defective DC bus fuse with one of the correct rating.