— 2 PSU, 1 gap between the facades: 716: 2 — 2 = 356mm;
— 4 identical PSUs, 3 gaps, for adjustment each gap is 4mm: (716 — 12): 4 = 176mm;
— 3 PSU, are combined from 2 small boxes with a facade of 176mm, and 1 deeper — 356mm, gaps 8mm: 176 x 2 + 356 + 8 = 716mm.