Mersen P266A Fuse Block. Mersen Fuse Block, Series: P266, 1000 VAC, 400 A, 1 Pole, 1 ph, Stud Connection, 16 to 3/8 AWG Wire, Threaded Mounting, For Use With: A60X, A60Z and A70QS-4 Series Form 101 Fuse, Phenolic, 6 in L x 2 in W x 2 in H Dimensions. Additional Description: MERS-P266A Fuse Block 1000VAC 1000VDC 400A 1-Pole Stud center to center: 4.06 inch. Catalog Description: Fuse Block 1000VAC 1000VDC 400A 1-Pole Stud center to center: 4.06 inch.