electrical - 100 amp sub-panel replacing old fuse box 100 amp sub-panel replacing old fuse box. Ask Question 1. I have this old fuse box in the attic (pictured, basically acting as a junction box) and 6 wires total running into it, 4 are knob and tube, so two are hot, two neutral, they all go dead when one 15 A breaker is tripped in the basement, and the other two wires are more Romex-like wires 100 amp fuse box | eBay NOS Eagle # 655 100 Amp 250 V AC Class H Cartridge Fuse Box of 4 See more like this. FPE FEDERAL PACIFIC FUSE BOX COVER & DOOR 1006 100 AMP . Pre-Owned. $50. or Best Offer +$15 shipping. Square D 33983-P 100 amp fuse box cover. Pre-Owned. $100. or Best Offer +$41 shipping.