Abstract: A motor control unit (MCU) and methods of operating and assembling the same are provided. The MCU includes a housing enclosing a retractable stab assembly (RSA) having stabs attached thereto. The MCU further includes a bracket assembly having a mount for securing the bracket assembly to the RSA, guiderails for slideably engaging the RSA to facilitate the extending and retracting motion, and a lead screw accessible via an opening in the front of the housing. Rotating the lead screw causes the RSA to extend and retract which engages and disengages the stabs. The MCU also includes a motor assembly having a drive motor coupled to a drive shaft. The motor rotates the shaft in response to control signals from a remote-device. The motor assembly attaches to the housing such that the rotation of the shaft in response to the signals rotates the lead screw to engage and disengage the stabs.

Abstract: Embodiments of a motor control unit for a motor control center and methods for servicing the same are provided. The motor control unit comprises a housing for enclosing one or more electrical components therein. The housing includes a retractable stab assembly and a lead screw assembly operably coupled thereto for extending and retracting one or more stabs for controlling the flow of power to the one or more electrical components.

Abstract: A motor control unit (MCU) and methods of operating the same are provided. The MCU includes a housing enclosing a retractable stab assembly (RSA) having stabs attached thereto. The MCU further includes a bracket assembly having a mount for securing the bracket assembly to the RSA, guiderails for slideably engaging the RSA to facilitate the extending and retracting motion, and a lead screw accessible via an opening in the front of the housing. Rotating the lead screw causes the RSA to extend and retract which engages and disengages the stabs. The MCU also includes a motor assembly having a drive motor coupled to a drive shaft. The motor rotates the shaft in response to control signals from a remote-device. The motor assembly attaches to the housing such that the rotation of the shaft in response to the signals rotates the lead screw to engage and disengage the stabs.

Abstract: Embodiments of a motor control unit for a motor control center and methods for servicing the same are provided. The motor control unit comprises a housing for enclosing one or more electrical components therein. The housing includes a retractable stab assembly and a lead screw assembly operably coupled thereto for extending and retracting one or more stabs for controlling the flow of power to the one or more electrical components.

Abstract: A motor control unit (MCU) and methods of operating and assembling the same are provided. The MCU includes a housing enclosing a retractable stab assembly (RSA) having stabs attached thereto. The MCU further includes a bracket assembly having a mount for securing the bracket assembly to the RSA, guiderails for slideably engaging the RSA to facilitate the extending and retracting motion, and a lead screw accessible via an opening in the front of the housing. Rotating the lead screw causes the RSA to extend and retract which engages and disengages the stabs. The MCU also includes a motor assembly having a drive motor coupled to a drive shaft. The motor rotates the shaft in response to control signals from a remote-device. The motor assembly attaches to the housing such that the rotation of the shaft in response to the signals rotates the lead screw to engage and disengage the stabs.

Abstract: A motor control unit (MCU) and methods of operating the same are provided. The MCU includes a housing enclosing a retractable stab assembly (RSA) having stabs attached thereto. The MCU further includes a bracket assembly having a mount for securing the bracket assembly to the RSA, guiderails for slideably engaging the RSA to facilitate the extending and retracting motion, and a lead screw accessible via an opening in the front of the housing. Rotating the lead screw causes the RSA to extend and retract which engages and disengages the stabs. The MCU also includes a motor assembly having a drive motor coupled to a drive shaft. The motor rotates the shaft in response to control signals from a remote-device. The motor assembly attaches to the housing such that the rotation of the shaft in response to the signals rotates the lead screw to engage and disengage the stabs.

Abstract: The arc-resistant MCC is provided with either the expansion chamber or the plenum. Arc flashes create pressure. Different arc-resistant MCC bases are used depending on whether the expansion chamber or the plenum is to be attached, as the expansion chamber and the plenum deal with the created pressure in different ways and are accordingly attached to the MCC base in different ways.

Abstract: A circuit breaker handle actuation device used in conjunction with a circuit breaker having a circuit breaker handle and an external handle located on an electrical enclosure. The device includes a stationary frame having first and second horizontal supports. The device also includes a rotatable frame having first and second horizontal elements which extend from first and second vertical elements, respectively. The first and second vertical elements are rotatably attached to the first and second horizontal supports. In addition, an opening for receiving the circuit breaker handle is located between the first and second vertical elements. Further, the device includes a rotatable bracket having first and second vertical arms which are rotatably attached to the first and second horizontal elements, respectively, wherein the rotatable bracket is connected to the external handle. Movement of the external handle between ON, OFF and RESET/PARK positions causes corresponding movement of the circuit breaker handle.

Abstract: A circuit breaker handle actuation device used in conjunction with a circuit breaker having a circuit breaker handle and an external handle located on an electrical enclosure. The device includes a stationary frame having first and second horizontal supports. The device also includes a rotatable frame having first and second horizontal elements which extend from first and second vertical elements, respectively. The first and second vertical elements are rotatably attached to the first and second horizontal supports. In addition, an opening for receiving the circuit breaker handle is located between the first and second vertical elements. Further, the device includes a rotatable bracket having first and second vertical arms which are rotatably attached to the first and second horizontal elements, respectively, wherein the rotatable bracket is connected to the external handle. Movement of the external handle between ON, OFF and RESET/PARK positions causes corresponding movement of the circuit breaker handle.

Abstract: The arc-resistant MCC is provided with either the expansion chamber or the plenum. Arc flashes create pressure. Different arc-resistant MCC bases are used depending on whether the expansion chamber or the plenum is to be attached, as the expansion chamber and the plenum deal with the created pressure in different ways and are accordingly attached to the MCC base in different ways.