Apparatus for interrupting an electrical circuit

A circuit interrupter comprising:

• a first current carrying path, electrically in series between incoming and outgoing conductors, including first and second stationary conductive elements and a movable conductive element, the movable conductive element being displaceable between a closed position wherein the first current carrying path is established and an open position wherein an expanding arc is formed with a stationary conductive element and the first current carrying path is interrupted;
• and
• a static second current carrying path electrically in series between the incoming and outgoing conductors, and electrically in parallel with the first current carrying path, the second current carrying path defining an open circuit section through which no current flows during normal operation of the interrupter when the conductive element is in the closed position, and including at least one variable resistance element electrically in series with and upstream of the open circuit section, the variable resistance element having a first resistance during normal operation when the first current carrying path is established, and the variable resistance element transitioning to a second, higher resistance in response to interruption of the first current carrying path to interrupt current through the first and second current carrying paths of the interrupter, the open circuit section including a plurality of spaced-apart conductors, at least one of the conductors contacting the expanding arc between the stationary and movable conductive elements electrically around the resistance element during transition from normal operation in response to interruption of the first current carrying path, whereby current is transitioned from the first current carrying path to the second current carrying path.

A circuit interrupter comprising:

• a pair of stationary conductive elements;
• a movable conductive element displaceable between a closed position wherein a first current carrying path electrically in series between incoming and outgoing conductors is established between the stationary conductive elements and an open position wherein an expanding arc is formed with the stationary conductive elements and the first current carrying path is interrupted;
• and
• at least one variable resistance element electrically coupled in a static second current carrying path electrically in series between the incoming and outgoing conductors, the static second current carrying path electrically in parallel with the first current carrying path, the second current carrying path forming an open circuit section and transmitting no current when the first current carrying path is established, the variable resistance element being disposed electrically in series with and upstream of the open circuit section and having a first electrical resistance to favor migration of current flow from the first current carrying path to the second current carrying path during an initial phase of interruption of the first current carrying path, and a second, higher electrical resistance during a subsequent phase of interruption to interrupt current through both the first and second current carrying paths of the interrupter, the open circuit section including a plurality of spaced-apart conductors, at least one of the conductors contacting the expanding arc between the movable conductive element and a stationary conductive element electrically around the resistance element during transition from the initial phase of operation to the subsequent phase of operation, whereby current is transitioned from the first current carrying path to the second current carrying path.

A circuit interrupter module for completing and interrupting an electrical current carrying path between a source and a load, the module comprising:

• a support assembly;
• first and second stationary conductive elements within the support assembly;
• a movable conductive element disposed within the support assembly, the movable conductive element being displaceable between a first position in contact between the stationary conductive elements and a second position spaced from the conductive elements to form an expanding arc therebetween;
• and
• a static transient current carrying path electrically in series between incoming and outgoing conductors, and defined at least partially within the support assembly, the static transient current carrying path being disposed electrically in parallel with the movable conductive element and forming an open circuit section, the transient current carrying path including at least one variable resistance element disposed electrically in series with and upstream of the open circuit section and in contact with either the first or the second stationary conductive element, the transient current carrying path conducting no current when the movable conductive element is in the first position and contributing to interruption of current through both the first and second current carrying paths of the module upon movement of the movable conductive element to the second position, the open circuit section including a plurality of spaced apart conductors, at least one of the conductors contacting the expanding arc between the movable conductive element and a stationary conductive element electrically around the resistance element during movement of the movable conductive element, whereby current is transitioned from the movable element to the transient current carrying path.