A double shutter shroud (5) and a flexible sheath (11) surrounding a stab (10) of an MCC unit, form a protective tunnel (30) for the stab to connect to a bus 4. A first shroud (6) mounted on the bus, includes a first gate (12). A second shroud (20) mounted on the MCC unit includes a second gate (24). When the MCC unit slides into an MCC section, a unit key (16) opens the first gate. When the stab is advanced toward the bus, a stab key (28) opens the second gate, forming a protective tunnel (30) from the flexible sheath and through the first and second shrouds. The protective tunnel protects the stab and bus from contamination, helps prevent dielectric breakdowns and short circuits between different phase busses, and protects an operator from electrical hazard of touching the bus or stab with tools or fingers.