I also found this file which helps some. The curves in the SKM library are showing the 104A fuse blowing at 25 amps and the 150A fuse blowing at about 50-60 amps (both long time), not 104 and 590 as the attached file suggests. The SKM curves don't even allow for transformer inrush.

Noticed this in the notes for the library file for the 9F59T:

8-83

These backup fuses are designed to interrupt currents above the minimum I/C shown below.

Fuses must be coordinated with a series device capable of clearing lower currents.

Rating (Amps) Min I/C (Amps)

40C 280

50C 300

65C 440

80C 580

100C 830

125C 475

150C 590

250C (2-125C) 900

300C (2-150C) 1080

And this for the 9F54WLD:

Current ratings are not assigned to distribution transformer internal fuses.

Refer Ermco Components Inc, for the KAIC and actual Amp ratings.

Doc # 32B548089(2 sheets)

Model Number Amp Rating (A)

9F54WLD002 24

9F54WLD102 41

9F54WLD202 74

9F54WLD302 104

9F54WLD303 104

9F54WLD402 146

9F54WLD502 200

9F54WLD602 272

Attachment:

Types-Ratings-of-Expulsion-Fuses-.pdf