An electrical unit for a Motor Control Center, MCC, the electrical unit comprising: a support structure for supporting an electrical component configured to receive first and second pluralities of signals from the MCC; a front wall and opposing sidewalls attached to the support structure, the front wall, the opposing sidewalls and the support structure forming an interior volume of the electrical unit containing the electrical component; an actuating mechanism for selectively moving the support structure with respect to the MCC, the actuating mechanism having a handle protruding through the front wall, the handle being moveable between a plurality of positions including: a first position corresponding to a connected position in which the support structure is fully inserted in the MCC with the first and second pluralities of signals being connected; a second position corresponding to a test position in which the support structure is partially inserted in the MCC with the first plurality of signals being disconnected and the second plurality of signals being connected; and a third position corresponding to a disconnected position in which the support structure is partially inserted in the MCC with the first and second pluralities of signals being disconnected, wherein the actuating mechanism comprises a cam pivotally mounted to the support structure and a linkage connecting the cam to the handle, wherein linear actuation of the handle rotates the cam to displace the support structure between the positions, characterized in that the linkage is configured to be retracted inward when not in use, thereby minimizing exterior protrusion from the electrical unit, and is configured to be extended outward to provide increased leverage to move the electrical unit between the positions; and in that the electrical unit further comprises sealing members (50, 52) attached to the opposing sidewalls in areas external to the interior volume of the electrical unit, wherein the sealing members form barriers in gaps leading to an interior volume of the MCC between the opposing sidewalls and the MCC to provide arc fault protection when the support structure is partially inserted in the MCC in the second and third positions. a support structure for supporting an electrical component configured to receive first and second pluralities of signals from the MCC; a front wall and opposing sidewalls attached to the support structure, the front wall, the opposing sidewalls and the support structure forming an interior volume of the electrical unit containing the electrical component; an actuating mechanism for selectively moving the support structure with respect to the MCC, the actuating mechanism having a handle protruding through the front wall, the handle being moveable between a plurality of positions including: a first position corresponding to a connected position in which the support structure is fully inserted in the MCC with the first and second pluralities of signals being connected; a second position corresponding to a test position in which the support structure is partially inserted in the MCC with the first plurality of signals being disconnected and the second plurality of signals being connected; and a third position corresponding to a disconnected position in which the support structure is partially inserted in the MCC with the first and second pluralities of signals being disconnected, wherein the actuating mechanism comprises a cam pivotally mounted to the support structure and a linkage connecting the cam to the handle, wherein linear actuation of the handle rotates the cam to displace the support structure between the positions, characterized in that the linkage is configured to be retracted inward when not in use, thereby minimizing exterior protrusion from the electrical unit, and is configured to be extended outward to provide increased leverage to move the electrical unit between the positions; and in that the electrical unit further comprises sealing members (50, 52) attached to the opposing sidewalls in areas external to the interior volume of the electrical unit, wherein the sealing members form barriers in gaps leading to an interior volume of the MCC between the opposing sidewalls and the MCC to provide arc fault protection when the support structure is partially inserted in the MCC in the second and third positions.