Switching accessory for use with motor starters

A switching accessory mounted on a motor starter, comprising:

• a lever;
• at least one movable contact element connected to said lever, said contact element movable to a position in which said contact element electrically connects at least two bus bars of said motor starter;
• a drive mechanism for moving said lever;
• a fulcrum shaft about which said lever may pivot, said fulcrum shaft movable between a first position and a second position, said lever pivotable about said fulcrum shaft when said fulcrum shaft is secured in said second position.

A motor starter comprising:

• a pull bar that is axially displaceable between at least one pair of bus bars, the pull bar being displaceable between a first position in which contacts of the bus bars of each at least one pair are isolated from one another and a second position in which the contacts of the bus bars of each pair are in electrical contact via contact elements on the pull bar;
• a motor driven actuator mechanism, said actuator mechanism including an actuator member that is displaceable between predetermined limit positions;
• a fulcrum shaft that is displaceable between predetermined limit positions;
• and
• an operating lever which is pivotally connected to the pull bar, the actuator member and the fulcrum shaft.

A method of switching electrical current through a motor starter, comprising:

• providing at least one pair of bus bars, each of said bus bars having a bus bar contact;
• pivotally connecting a pull bar, a fulcrum shaft, and a lever, said pull bar having contact elements,
• pivotally displacing said lever about a first fulcrum point provided by the point of connection between the pull bar and the operating lever,
• displacing said fulcrum shaft from a first position to an operating position;
• pivotally displacing said lever about a second fulcrum point provided by the point of connection between the pull bar and the fulcrum shaft;
• and
• contacting said bus bar contacts and said pull bar contact elements for allowing electrical conduction between said bus bars of said bus bar pair.

A switching apparatus having bus bars, said apparatus for starting an electric motor and conaprising:

• a pull bar having contactors spaced along its length and configured to connect said bus bars when said pull bar is moved along its length from a first position to a second position;
• and
• a mechanical mechanism operable to quickly move said pull bar from its first position to its second position, said mechanism including:
• (1) a lever having a first end, a second end, and a central fulcrum, said lever pivotally connected at said first end to said pull bar for moving said pull bar to said second position;
• (2) a fulcrum support connected to said central fulcrum of the lever;
• and
• (3) a quick release mechanical energy source coupled to the second end of the lever and operable upon release to drive said second end so as to move said first end and thereby said pull bar to said second position.

A switching apparatus having sets of bus bars, said apparatus for starting an electric motor and cornprising:

• a contactor pull bar, a fulcrum bar and an actuator member mounted generally parallel, having corresponding first and second ends, and being reversibly and longitudinally movable between corresponding retracted positions and extended positions with said extended positions being in the same direction as said first ends;
• an operating lever pivotally connected at a first end to the first end of the actuator member, at a second end to the first end of the pull bar, and at a point between the ends of the lever to the first end of the fulcrum bar;
• and
• a plurality of electrical contactors spaced along and mounted on the pull bar in a configuration to contact contactor sites on said bus bars to form electrical contact between said sets of bus bars when said pull bar is in its extended position, said actuator member, said fulcrum bar and said pull bar being normally in their retracted positions when said contactors are in an open position.

A method of switching electrical current through a plurality of bus bars of a motor starter with a switch to allow current to flow in a bypass manner around at least one current control element of said motor starter, said method comprising:

• providing said at least one current control element, said current control element electrically connected to at least two of said plurality of bus bars;
• providing a plurality of electrical contactors, each of said contactors have a first and second contact element, electrical current flowing through said contactors to said bus bars when said contactors are closed such that said first contact element is connected to said second contact element, said current flow through said contactors providing a current bypass route between said bus bars and around said current control element;
• driving said first contact elements towards said second contact elements with a first contact force;
• connecting said first and second contact elements when said first contact force is being applied between said first and second contact elements;
• and
• applying a second contact force between said first and second contact elements after said connecting step to hold said first and second contact elements in a contact state, said second contact force having a greater magnitude than said first contact force.

A method of switching an electrical current in a plurality of bus bars of a motor starter with a switch to allow current to flow in a bypass manner around at least one current control element of a motor starter, said method comprising:

• providing said at least one current control element, said current control element electrically connected to at least two of said plurality of bus bars;
• providing a plurality of first contact locations on said bus bars;
• providing at least one moveable contact element, said moveable contact element switching a current flow in said bus bars when said moveable contact element contacts said first contact locations, so that said current flow flows between said bus bars while bypassing said at least one current control element;
• activating said switch when a change in said current flow is desired;
• and slowly implementing said change in said current flow after said switch is activated.