Abstract: A passive arc control system for a motor control center 60 includes an arc attenuating box having sides separating adjacent vertical bus bar phases 54, providing a physical barrier to arc flash energy. The box is open at its top and bottom forming a chimney 55. A shutter assembly for each box includes an insulator cap 62 on a free end of the bus bar and an independently moveable, box-shaped shutter 64 that slides along the bus bar away from the insulator cap, when a device is connected to the bus bar. The shutter has an opening 65 through which the bus bar passes when the device is connected to the bus bar and an opening 55? aligned with the box's chimney. The arc control system provides a high degree of arc protection for personnel working around open motor control centers and is highly modular and easy to construct.

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 connect/disconnect mechanism for an MCC unit, prevents a circuit breaker from being turned on while the unit is being inserted into an MCC section, until stabs of the unit have been connected to a power bus. A cam is rotatably mounted on a pivoted platform in the MCC unit, an actuating arm is coupled between a unit on/off handle of the MCC unit and the cam, and a bail is pivotally mounted on the pivoting platform and connected to a switch handle of the breaker. A cam surface in a slot of the cam is configured to engage a pin projecting from the bail, when the pivoted platform is forced in a backward direction to connect the stabs to the bus, thereby operatively connecting the unit on/off handle to the switch handle of the breaker.

Abstract: A passive arc control system for a motor control center 60 includes an arc attenuating box having sides separating adjacent vertical bus bar phases 54, providing a physical barrier to arc flash energy. The box is open at its top and bottom forming a chimney 55. A shutter assembly for each box includes an insulator cap 62 on a free end of the bus bar and an independently moveable, box-shaped shutter 64 that slides along the bus bar away from the insulator cap, when a device is connected to the bus bar. The shutter has an opening 65 through which the bus bar passes when the device is connected to the bus bar and an opening 55? aligned with the box's chimney. The arc control system provides a high degree of arc protection for personnel working around open motor control centers and is highly modular and easy to construct.

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 connect/disconnect mechanism for an MCC unit, prevents a circuit breaker from being turned on while the unit is inserted inserted into an MCC section, until stabs of the unit have been connected to a power bus. A cam is rotatably mounted on a pivoted platform in the MCC unit, an actuating arm is coupled between a unit on/off handle of the MCC unit and the cam, and a bail is pivotally mounted on the pivoting platform and connected to a switch handle of the breaker. A cam surface in a slot of the cam is configured to engage a pin projecting from the bail, when the pivoted platform is forced in a backward direction to connect the stabs to the bus, thereby operatively connecting the unit on/off handle to the switch handle of the breaker.

Abstract: A swing mount 110 for a terminal block includes a hinge 122 mounted on a wall 105 of an electrical enclosure 100, located near an opening 115 in the wall, for passing a movable plug connector 112 from inside the enclosure to connect to a terminal block 114 outside the enclosure. A lever 124 is carried by the hinge, for moving the moveable connector. A guide 130 for directing movement of the movable connector is mounted on the wall near the opening. A connector support 126 is mounted on the lever, supporting the movable connector, the support including a pin 138 that slideably engages a longitudinal slot 140 in the lever to move the support toward or away from the terminal block when the lever is actuated. The support includes a guide rail 134 that slides through slot 136 in the guide to align the movable connector with the opening.

Abstract: A swing mount 110 for a terminal block includes a hinge 122 mounted on a wall 105 of an electrical enclosure 100, located near an opening 115 in the wall, for passing a movable plug connector 112 from inside the enclosure to connect to a terminal block 114 outside the enclosure. A lever 124 is carried by the hinge, for moving the moveable connector. A guide 130 for directing movement of the movable connector is mounted on the wall near the opening. A connector support 126 is mounted on the lever, supporting the movable connector, the support including a pin 138 that slideably engages a longitudinal slot 140 in the lever to move the support toward or away from the terminal block when the lever is actuated. The support includes a guide rail 134 that slides through slot 136 in the guide to align the movable connector with the opening.