Motor control center unit disconnect with interlocks

Patent metadata

Field	Value
Publication number	US-2016233033-A1
Application number	US-201315023837-A
Country	US
Kind code	A1
Filing date	Sep 27, 2013
Priority date	Sep 27, 2013
Publication date	Aug 11, 2016
Grant date	—

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.

First claim

What is claimed is:

1 . A connect/disconnect mechanism for a motor control center unit, comprising:
a cam rotatably mounted on a cam shaft mounted on a pivoted platform in a motor control center unit, having a cam surface in a slot opening on a periphery of the cam, the pivoted platform supporting a circuit breaker and stabs electrically connected to the breaker that are configured to connect to a power bus when the pivoted platform is forced backward; an actuating arm coupled between a unit on/off handle located on a front side of the motor control center unit and the cam, the actuating arm configured to rotate the cam in response to actuation of the unit on/off handle, and to cause the cam to rotate as the cam shaft follows a pivoting motion of the pivoted platform relative to a position of the actuating arm; and a bail pivotally mounted on the pivoting platform and connected to a switch handle of the circuit breaker, the bail having a pin projecting therefrom, the cam surface in the slot of the cam being configured to engage the pin of the bail in a first position when the pivoted platform is forced backward to connect the stabs to the power bus, thereby operatively connecting the unit on/off handle to the switch handle of the circuit breaker.

2 . The connect/disconnect mechanism for a motor control center unit of claim 1 , further comprising:
the cam surface in the slot of the cam being further configured to disengage the pin of the bail in a second position when the pivoted platform is forced forward to disconnect the stabs from the bus, thereby operatively disconnecting the unit on/off handle on the front side of the motor control center unit from the switch handle of the circuit breaker.

3 . The connect/disconnect mechanism for a motor control center unit of claim 1 , further comprising:
a handle interlock coupled to the unit on/off handle, configured to block movement of an advance/retract mechanism coupled to the stabs, when the unit on/off handle is moved into an on position, to thereby prevent disconnecting the stabs from the power bus until the unit on/off handle is moved to an off position; the cam surface in the slot of the cam being configured to move the bail and the switch handle of the circuit breaker to turn off the circuit breaker when the unit on/off handle is moved to the off position while the stabs are connected to the power bus; and the cam surface in the slot of the cam being configured to disengage the pin of the bail when the stabs are disconnected from the power bus by the advance/retract mechanism, thereby operatively disconnecting the unit on/off handle from the switch handle of the circuit breaker that has been turned off.

4 . The connect/disconnect mechanism for a motor control center unit of claim 1 , further comprising:
a unit interlock coupled to the pivoting platform, configured to block removal of the motor control center unit from a motor control center, when the pivoted platform is forced backward to connect the stabs to the bus.

5 . A motor control center unit, comprising:
a housing configured to be inserted into a motor control center, the housing including an outer structure comprising side walls, a bottom plate, a back wall, and a front door hinged to one of the side walls and configured to open a front side of the housing to provide access to an interior space, an exterior face of the back wall of the housing being configured to be located adjacent to an electrical power bus when the housing has been inserted into the motor control center; a pivoted platform mounted on a pivot fastened to an interior face of the back wall of the housing, the platform supporting a circuit breaker on a front side of the platform and supporting stabs on a back side of the platform, the stabs being electrically connected to a circuit breaker electrical switch actuated by a circuit breaker switch handle of the circuit breaker, the stabs configured to project through an opening in the back wall of the housing, to mechanically and electrically engage the power bus for electrical connection therewith, when the platform is pushed in a backward direction on the pivot against the back wall; an advance/retract handle located on the front side of the housing, connected to an advance/retract mechanism configured to push the pivoted platform to connect the stabs to the power bus or pull the pivoted platform to disconnect the stabs from the power bus; a connect/disconnect mechanism located within the housing, comprising a cam, an actuating arm, and a bail with a pin: the cam of the connect/disconnect mechanism, being rotatably mounted on a cam shaft mounted on the pivoted platform in the housing, having a cam surface in a slot opening on a periphery of the cam; the actuating arm of the connect/disconnect mechanism, being coupled between a unit on/off handle located on the front side of the housing and the cam, the actuating arm configured to rotate the cam in response to actuation of the unit on/off handle, and to cause the cam to rotate as the cam shaft follows a pivoting motion of the pivoted platform relative to a position of the actuating arm; and the bail of the connect/disconnect mechanism, being pivotally mounted on the pivoting platform and connected to the switch handle of the circuit breaker, the bail having the pin projecting therefrom, the cam surface in the slot of the cam being configured to engage the pin of the bail in a first position when the pivoted platform is forced backward by the advance/retract mechanism, to connect the stabs to the power bus, thereby operatively connecting the unit on/off handle to the switch handle of the circuit breaker.

6 . The motor control center unit of claim 5 , further comprising:
the cam surface in the slot of the cam being further configured to disengage the pin of the bail in a second position when the pivoted platform is forced forward by the advance/retract mechanism, to disconnect the stabs from the bus, thereby operatively disconnecting the unit on/off handle from the switch handle of the circuit breaker.

7 . The motor control center unit of claim 5 , further comprising:
a handle interlock coupled to the unit on/off handle, configured to block movement of the advance/retract mechanism coupled to the stabs, when the unit on/off handle is moved into an on position, to thereby prevent disconnecting the stabs from the power bus until the unit on/off handle is moved to an off position; the cam surface in the slot of the cam being configured to move the bail and the switch handle of the circuit breaker to turn off the circuit breaker when the unit on/off handle is moved to the off position while the stabs are connected to the power bus; and the cam surface in the slot of the cam being configured to disengage the pin projecting from the bail when the stabs are disconnected from the power bus by the advance/retract mechanism, thereby operatively disconnecting the unit on/off handle from the switch handle of the circuit breaker that has been turned off.

8 . The motor control center unit of claim 5 , further comprising:
a unit interlock coupled to the pivoting platform, configured to block removal of the housing from the motor control center, when the pivoted platform is forced backward by the advance/retract mechanism, to connect the stabs to the bus.

Assignees

• Schneider Electric Usa Inc

Inventors

• Richards Walter J
• Rosen Gary M

Classifications

• H01H9/22 Primary

  for interlocking between casing, cover, or protective shutter and mechanism for operating contacts {(explosion-proof cases H01H9/045; built-in fuses and interlocking mechanisms H01H9/104; by automatic release of circuit breakers H01H71/126)} · CPC title

• H02B1/36

  with withdrawable units · CPC title