The invention is generally directed to connectors for a motor control unit.
A motor control center (MCC) is an electrical cabinet dedicated to motor control. A motor control unit is generally a drawer-like container of electrical components, such as circuit breakers, motor starters, and pilot devices, which slides into a front section of an MCC and connects to a common power bus running vertically along the back side or back section of the MCC.
In order to provide access for pilot device signals and test signals, the motor control unit generally includes a feed-through connector mounted through a side wall of its enclosure. The control signals may include, for example, low voltage signals for pilot lights, push buttons, selector switches, or other control devices. The test signals may include, for example, low voltage signals for diagnostic maintenance, from internal test points.
In an example embodiment of the invention, a feed-through connection for an electrical enclosure, such as a motor control unit, may be connected or disconnected by an operator without first opening a wire-way along the outside of the electrical enclosure. A swing mount enables quickly connecting or disconnecting a moveable pluggable connector to a stationary terminal block located outside the electrical enclosure. The swing mount is carried on a hinge on an interior wall of the electrical enclosure. The hinge is located on one side of an opening in the wall. The opening is for passing the movable plug connector from inside the electrical enclosure to connect to a stationary terminal block located generally outside the electrical enclosure. A lever is pivotally mounted on the hinge, for actuating the swing mount to move the moveable plug connector toward or away from the stationary terminal block. An example guide may be mounted on the wall of the electrical enclosure and located near the opening in the wall. A connector support is mounted on the lever, the connector support supporting the movable plug connector. The connector support is preferably captured in a guide mounted to the interior wall. The connector support may include a pin that slideably engages a longitudinal slot in the lever to move the connector support toward or away from the stationary terminal block when the lever is actuated. The connector support may include a guide rail that slides through a slot in the guide to align the movable plug connector with the opening in the wall of the electrical cabinet. Other configurations for a guide and additional positioning elements between the terminal block and plug connector may be used. By actuating the lever, the moveable plug connector may be connected to or disconnected from the stationary terminal block without first opening a wire-way along the side of the electrical cabinet.
In an example embodiment, the lever may be a generally U-shaped frame having respective ends pivotally mounted on the hinge. An upper portion of the U-shaped lever may include the longitudinal slot and may be generally arcuate in shape, beginning near the hinge and extending toward the longitudinal slot. The U-shaped lever may include a lower portion of the lever with a lower longitudinal slot. The connector support may include a lower pin that slideably engages the lower longitudinal slot in the lower portion of the lever to move the connector support, in unison with the upper portion of the lever, toward or away from the stationary terminal block when the lever is actuated.
Since space is limited inside the motor control unit 100, in previous motor control systems, an external wire-way along the side of the motor control unit 100 had to be opened to enable maintenance personnel to access the outside of the terminal block 114 for connection with a feed-through connector mounted through the wall of the motor control unit 100 enclosure. The feed-through connector was secured to the stationary terminal block 100 with screws or other fasteners. Later, when the motor control unit 100 was to be removed from the MCC cabinet 90 for service, the external wire-way along the side of the motor control unit 100 had to be reopened to gain access to the stationary terminal block 114 to disconnect the feed-through connector of the motor control unit 100.
In an example embodiment of the invention, a feed-through connection for an electrical enclosure, such as the motor control unit 100, may be established or disconnected by an operator without first opening an external wire-way along the outside of the enclosure of the motor control unit 100. The swing mount 110 shown in the figure, enables quickly connecting or disconnecting the moveable pluggable connector 112 and the stationary terminal block 114 located outside the electrical enclosure.
A lever 124 is pivotally carried on a hinge 122 mounted on an interior surface of a wall 105 of the motor control unit 100 electrical enclosure. The hinge is located on an interior side of an opening 113 in the wall, the opening 113 for passing the movable plug connector 112 from inside the electrical enclosure of the motor control unit 100, to connect with the stationary terminal block 114 outside the electrical enclosure of the motor control unit 100. The lever 124 actuates the swing mount 110 to move the moveable plug connector 112 toward or away from the stationary terminal block 114.
A connector support 126 is mounted on the lever 124, the connector support 126 supporting the movable plug connector 112. The connector support 126 includes a pin 138 (shown in
The 124 lever is a generally U-shaped frame pivotally mounted on the hinge 122, with an upper portion of the lever including the longitudinal slot 140. The lever 124 has one end mounted on the hinge 122 and may have a generally arcuate shape beginning near the hinge 122 and extending toward the longitudinal slot 140. The lever has a lower portion 124′ including a lower longitudinal slot 140′ (shown in
A guide 130 is mounted on the wall 105 of the electrical enclosure of the motor control unit 100 and is located near the opening 113 in the wall 105. The connector support 126 includes a guide rail 134 that slides through a slot 136 in the guide 130 to align the movable plug connector 112 with the opening 113 in the wall 105 of the electrical enclosure of the motor control unit 100. A second guide 130′ (shown in
The lever has a lower portion 124′ including a lower longitudinal slot 140′. The connector support 126 includes a lower pin (not shown) that slides in the lower longitudinal slot 140′ as the moveable plug connector 112 moves toward or away from the stationary terminal block 114, in a similar manner to that described for the action of the pin 138 in the longitudinal slot 140. The connector support 126 includes a second guide rail 134′ that slides through a slot 136′ in the second guide 130′ to align the movable plug connector 112 with the opening 113 in the wall 105 of the electrical enclosure. Both of the guides 130 and 130′ are mounted on the wall 105 of the electrical enclosure of the motor control unit 100, but in the perspective, exploded view of
In operation, the motor control unit 100 is inserted by the operator into an available slot of the MCC cabinet 90, so that the opening 113 in the wall 105 of the motor control unit 100 enclosure, is lined up with the externally accessible, stationary terminal block 114 mounted on the motor control center 90 structure outside the motor control unit 100. The swing mount 110 is then actuated to pass the movable plug connector 112 from inside the motor control unit 100 enclosure, to connect with the stationary terminal block 114 outside the motor control unit 100 enclosure. The movable plug connector 112 is connected through the opening 113 in the wall 105 of the motor control unit 100 enclosure, to the externally accessible terminal block 114.
In an example embodiment of the invention, a method for connecting a connector conveying signals from inside an electrical enclosure, to a terminal block mounted outside the electrical enclosure, comprises the steps of:
lining up an opening in a wall of an electrical enclosure, to an externally accessible terminal block mounted outside the electrical enclosure;
passing a movable plug connector from inside the electrical enclosure, through the opening in the wall of the electrical enclosure, toward the terminal block, the moveable plug connector conveying signals from inside the electrical enclosure; and
connecting the moveable plug connector through the opening in the wall of the electrical enclosure, to the externally accessible terminal block mounted outside the electrical enclosure.
Although specific example embodiments of the invention have been disclosed, persons of skill in the art will appreciate that changes may be made to the details described for the specific example embodiments, without departing from the spirit and the scope of the invention.