Switch disconnector systems suitable for molded case circuit breakers and related methods

A circuit breaker, comprising:

• a housing;
• an arc chute in the housing and comprising a plurality of stacked arc chute plates;
• a movable contact arm in the housing and holding a moving contact;
• a line terminal in the housing and comprising a terminal end portion that faces a line side of the housing, wherein, the terminal end portion merges into an arm segment that has a first portion that angles upward at a first angle, wherein the first portion of the arm segment merges into a second portion that angles away from the first portion of the arm segment at a second angle, and wherein the arm segment merges into a base segment that extends beneath the arm segment and that is coupled to a wall of the housing;
• and
• a stationary contact in the housing and held by the arm segment of the line terminal,
• wherein at least one of the arc chute plates that neighbors the stationary contact is of a different material than at least another one of the arc chute plates, and wherein at least the another one of the arc chute plates is configured to be magnetized to a range of 1.50-2.00 Tesla at 5.5 kA current exposure.

A circuit breaker, comprising:

• a housing;
• an are chute in the housing and comprising a plurality of stacked arc chute plates;
• a movable contact arm in the housing and holding a moving contact;
• a line terminal in the housing and comprising a terminal end portion that faces a line side of the housing, wherein, the terminal end portion merges into an arm segment that has a first portion that angles upward at a first angle, wherein the first portion of the arm segment merges into a second portion that angles away from the first portion at a second angle, and wherein the arm segment merges into a base segment that extends beneath the arm segment and that is coupled to a wall of the housing;
• and
• a stationary contact in the housing and held by the arm segment of the line terminal,
• wherein the plurality of arc chute plates comprise a first sub-set that have a different material than a second sub-set, and wherein the second sub-set reside closest to the stationary contact, are non-ferromagnetic and produce a magnetic field at 5.5 kA that is in a range of 0.20-0.00 Tesla.

An arc chute assembly for a circuit breaker, comprising:

• a first sidewall;
• a second sidewall spaced apart from and coupled to the first sidewall;
• and
• a plurality of stacked are chute plates supported by the first and second sidewalls, wherein a first plurality of the stacked arc chute plates comprise a first material and a second plurality of the stacked arc chute plates comprise a second material different from the first material, wherein the second material is non-ferromagnetic, wherein the second plurality of the stacked arc chute plates reside below the first plurality of stacked arc chute plates and, in position in the circuit breaker, are configured to be closer to a stationary contact, and wherein the first plurality of the stacked arc chute plates is present in a greater number than the second plurality of the stacked arc chute plates.

An arc chute assembly for a circuit breaker, comprising:

• a first sidewall;
• a second sidewall spaced apart from and coupled to the first sidewall;
• and
• a plurality of stacked arc chute plates supported by the first and second sidewalls, wherein a first plurality of the stacked arc chute plates comprise a first material and a second plurality of the stacked arc chute plates comprise a second material different from the first material, wherein the second material is non-ferromagnetic,
• wherein the first plurality of the stacked arc chute plates is present in a greater number than the second plurality of the stacked arc chute plates, and
• wherein the first material of the stacked arc chute plates is low carbon steel grade 1010-1012.

A circuit breaker comprising:

• a housing;
• a movable contact arm in the housing and holding a moving contact;
• a line terminal in the housing and comprising a terminal end portion that faces a line side of the housing;
• a stationary contact in the housing and held by the line terminal;
• and
• an arc chute assembly in the housing, the arc chute assembly comprising:
• a first sidewall;
• a second sidewall spaced apart from and coupled to the first sidewall;
• and
• a plurality of stacked arc chute plates supported by the first and second sidewalls,
• wherein the first and second sidewalls of the arc chute assembly have opposing first and second ends with a length dimension therebetween, wherein the plurality of the stacked arc chute plates terminate a distance from second ends of the sidewalls to define a gap space under a bottommost arc chute plate of the stacked arc chute plates, wherein a forward end portion of the movable contact arm resides in the gap space, and wherein the movable contact arm including the forward end is external to the arc chute plates or resides under an upper surface of an arc chute plate that is closest to the stationary contact when the moving contact and the stationary contact are coupled together in a closed position, and wherein the stationary contact resides above the terminal end portion of the line terminal wherein the distance from the second ends that the stacked arc chute plates terminate is in a range of 1-2 inches, wherein the plurality of stacked are chute plates comprise a first sub-set that have a different material than a second sub-set, and wherein the second sub-set reside closest to the stationary contact, are non-ferromagnetic and produce a magnetic field at 5.5 kA that is in a range of 0.20-0.00.

A method of improving withstand current in a circuit breaker, comprising:

• providing a circuit breaker comprising a housing with an arc chamber comprising an arc chute with stacked arc chute plates and a line terminal with a stationary contact, and a movable contact arm with a moving contact, wherein the line terminal is a single piece shaped body that comprises a terminal end portion that faces a line side of the housing, wherein, the terminal end portion merges into an arm segment that has a first portion that angles toward the stationary contact at a first angle, wherein the first portion of the arm segment merges into a second portion that angles down away from the stationary contact at a second angle, wherein the arm segment merges into a base segment that extends beneath the arm segment and that is coupled to a wall of the housing of the circuit breaker, wherein the second portion of the arm segment holds the stationary contact, wherein the base segment comprises a leg, and wherein the second portion of the arm segment extends a distance toward the first portion and a distance away from the stationary contact in a direction away from the first portion before merging into the leg of the base segment;
• directing electrical current to travel along a current path that extends from the terminal end portion of the line terminal directly to the arm segment then to the stationary contact, then to the moving contact and to the contact arm;
• and
• producing a magnetic field in a first sub-set of the arc chutes when exposed to a 5.5 kA current level that is in a range of 0.20-0.00 Tesla while magnetizing a second sub-set of the arc chutes that reside above the first sub-set of the arc chutes in a range of 1.50-2.00 Tesla when exposed to the 5.5 kA current level.