Abstract: 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.

Abstract: A spring loaded, bistable connect/disconnect mechanism for a motor control center (MCC) unit 20, provides a secure and quick means to connect and disconnect the stab 30 of a MCC unit to a vertical power bus 24. The low profile mechanism comprises a series of flat links 6, 7, and 11 and an over-center spring 8 in the top of the MCC unit, for efficient use of space. The mechanism provides an additional force to quickly connect and disconnect the stabs to and from the power bus. The mechanism enables safe insertion and removal of the MCC unit from an MCC section, by incorporating interlocks 5 to prevent the MCC unit from being inserted when the stabs are extended and to prevent the MCC unit from being removed when the stabs are extended. Interlocks prevent the extension or retraction of the stabs when the handle is in an ON position.

Abstract: 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.

Abstract: A spring loaded, bistable connect/disconnect mechanism for a motor control center (MCC) unit 20, provides a secure and quick means to connect and disconnect the stab 30 of a MCC unit to a vertical power bus 24. The low profile mechanism comprises a series of flat links 6, 7, and 11 and an over-center spring 8 in the top of the MCC unit, for efficient use of space. The mechanism provides an additional force to quickly connect and disconnect the stabs to and from the power bus. The mechanism enables safe insertion and removal of the MCC unit from an MCC section, by incorporating interlocks 5 to prevent the MCC unit from being inserted when the stabs are extended and to prevent the MCC unit from being removed when the stabs are extended. Interlocks prevent the extension or retraction of the stabs when the handle is in an ON position.