Rhapsodi, I don't think their is any convention. Most the holder is just two sets of clips.
Take the fuse out and use a meter with one lead on one of the clips and the other on one of the ac IEC blades. You want to identify the clip with the least resistance to the blade. The arrow of the directional fuse should go from that clip to the other.
Sebrof, I certainly don't try everything that people come with, but this was so easy. Incidentally, many were strongly suggesting using copper tubing over the chassis IEC plug. There was even a video showing its effectiveness. I tried it and found it worthless. I guess it would depend on how well ones power cords are designed and made.
Take the fuse out and use a meter with one lead on one of the clips and the other on one of the ac IEC blades. You want to identify the clip with the least resistance to the blade. The arrow of the directional fuse should go from that clip to the other.
Sebrof, I certainly don't try everything that people come with, but this was so easy. Incidentally, many were strongly suggesting using copper tubing over the chassis IEC plug. There was even a video showing its effectiveness. I tried it and found it worthless. I guess it would depend on how well ones power cords are designed and made.