Abstract: A closed door operation racking device is provided for racking a circuit breaker to and from a power bus from outside of a housing of a motor control center unit. The racking device includes a racking operator assembly and a push-button interlock assembly. The racking operator is configured to rack-in the electrical device and connect the stabs to a power bus in a connected position and to rack-out the electrical device and disconnect the stabs from the power bus in a disconnected position. The push-button interlock assembly prevents the operation of the racking operator under certain conditions, and includes a spring-loaded locker assembly and a spring-loaded push-button operator assembly. A push-button operator of the push-button operator assembly is depressed to disengage the locker assembly from the racking operator to allow operation of the racking operator.

Abstract: A closed door operation racking device is provided for racking a circuit breaker to and from a power bus from outside of a housing of a motor control center unit. The racking device includes a racking operator assembly and a push-button interlock assembly. The racking operator is configured to rack-in the electrical device and connect the stabs to a power bus in a connected position and to rack-out the electrical device and disconnect the stabs from the power bus in a disconnected position. The push-button interlock assembly prevents the operation of the racking operator under certain conditions, and includes a spring-loaded locker assembly and a spring-loaded push-button operator assembly. A push-button operator of the push-button operator assembly is depressed to disengage the locker assembly from the racking operator to allow operation of the racking operator.

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 troubleshooting compartment for a motor control center unit, provides electrical access to test control points inside the motor control center unit, without exposing the operator to electrical hazards from the main line-voltage components inside the motor control center unit. The troubleshooting compartment comprises an accessible compartment contained within a motor control center unit, which is separate from a main line-voltage compartment of the motor control center unit, the accessible compartment having an access side to enable operator access to the accessible compartment without need to open the main line-voltage compartment; an accessible compartment door covering the access side of the accessible compartment from a front side of the motor control center unit; and feed-through terminals mounted within the accessible compartment, for test points and pilot devices operating at low, control voltages.

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 troubleshooting compartment for a motor control center unit, provides electrical access to test control points inside the motor control center unit, without exposing the operator to electrical hazards from the main line-voltage components inside the motor control center unit. The troubleshooting compartment comprises an accessible compartment contained within a motor control center unit, which is separate from a main line-voltage compartment of the motor control center unit, the accessible compartment having an access side to enable operator access to the accessible compartment without need to open the main line-voltage compartment; an accessible compartment door covering the access side of the accessible compartment from a front side of the motor control center unit; and feed-through terminals mounted within the accessible compartment, for test points and pilot devices operating at low, control voltages.

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.