Device, circuit, system, and method for contact sequencing are discussed. An electrical circuit includes a first pair of terminals adapted to be connected across a first set of switchable contacts, and a second pair of terminals adapted to be connected across a second set of switchable contacts that are coupled to an arc suppression circuit. A controller circuit is coupled to the first and second pairs of terminals and is configured to sequence activation or deactivation of the first and second sets of contacts based on a contact control signal. A first power switching circuit is coupled to the first pair of terminals and the controller circuit. The first power switching circuit is configured to switch power from an external power source and to trigger the activation or the deactivation of the first set of switchable contacts based on a first logic state signal from the controller circuit.

A contactor assembly and method for operating the contactor assembly can include a first conductor having a first set of axially extending protrusions and a second conductor having a second set of axially extending protrusions interdigitally arranged with the first set of protrusion. At least a subset of the first set of extending protrusions and at least a subset of the second set of protrusions can be conductively connected.

Disclosed herein are passive triggering mechanisms for activation of pyrotechnic features within electrical switching devices, such as contactor devices and fuse devices. The activation of the pyrotechnic features is configured to change the configuration of the internal components of the switching device and prevent current flow through the device. In some embodiments, the triggering mechanisms comprise features that respond to a magnetic field, such as a reed switch. In some embodiments, the reed switch responds to elevated current flow and can then use the signal with the elevated current flow to activate the pyrotechnic feature. In other embodiments, the reed switch uses a power signal from a secondary power source to activate the pyrotechnic feature.

A high speed arc suppressor and method include a first phase-specific arc suppressor configured to suppress arcing across contacts of the power contactor in a positive domain and a second phase-specific arc suppressor configured to suppress arcing across the contacts in a negative domain. First and second high speed switches are configured to enable and disable operation of an associated one of the first and second phase-specific arc suppressors. First and second drivers are configured to drive the first and second high speed switches.

The main body frame includes a first frame including a flexible protruding plate portion, a second frame facing the first frame in a first direction to form the housing section, and a snap-fit mechanism connecting the first frame to the second frame. The snap-fit mechanism includes a fitted portion provided on the flexible protruding plate portion and a fitting projection portion provided on a side wall of the second frame and fitting with the fitted portion. The fitting projection portion and the fitted portion are fitted by bringing the first and second frames into relative proximity in the first direction, and the fitting is released by relatively displacing the first and second frames in a second direction orthogonal to the first direction.

A power distribution unit includes a housing having walls defining a main cavity provided at a first side and a secondary cavity provided at a second side. The power distribution unit includes a main contactor received in the main cavity having first and second fixed contacts and a movable contact movable between a mated position and an unmated position to electrically connect the first and second fixed contacts. The main contactor includes a coil assembly energized to move the movable contact. The power distribution unit includes a pre-charge assembly received in the secondary cavity having a control circuit board, a pre-charge resistor coupled to the control circuit board, and a pre-charge switch coupled to the control circuit board. The power distribution unit includes a cover coupled to the housing to enclose the pre-charge assembly in the secondary cavity.

A power contact health assessor system includes a pair of terminals adapted to be connected to a set of switchable contact electrodes of a power contact and a contact separation detector configured to determine a time of separation of the set of switchable contact electrodes during deactivation of the power contact. The system includes a controller circuit operatively coupled to the pair of terminals and the contact separation detector. The controller circuit is configured to determine within a first observation window, a plurality of contact stick durations and an average contact stick duration. One or more additional observation windows with corresponding average contact stick durations are configured. A health assessment for the set of switchable contact electrodes may be based on a subsequent contact stick duration for a contact cycle after the first observation window and the corresponding average contact stick durations for the one or more additional observation windows.

An auxiliary contact unit including: a pair of fixed contact pieces; a movable contact piece arranged in a contactable and separable manner to and from the pair of fixed contact pieces; an auxiliary contact support configured to hold the movable contact piece and move in conjunction with opening/closing operation of an electromagnetic contactor; and a unit case configured to house the pair of fixed contact pieces, the movable contact piece, and the auxiliary contact support in a housing portion formed with joining portions of respective ones of a first case member and a second case member opposed to each other, wherein the joining portions of the respective ones of the first and second case members are air-tightly joined to each other.

A contactor, and an air conditioning system incorporating the contactor are provided. The contactor includes a body with an upper surface, a line-side electrical terminal located on one end of the body, a load-side electrical terminal located on the other side of the body, a switching element within the body, the switching element coupled between the line-side electrical terminal and the load-side electrical terminal, and a refrigerant mitigating element disposed on the upper surface. The line-side electrical terminal is configured to receive electrical power from an electrical grid. The load-side electrical terminal is configured to transfer at least a portion of the electrical power to at least one component of the outdoor unit. The switching element is configured to electrically connect the line-side electrical terminal and the load-side electrical terminal when activated. The refrigerant mitigating element may help mitigate the ignition of a refrigerant.

A power contact health assessor system includes a pair of terminals adapted to be connected to a set of switchable contact electrodes of a power contact and a contact separation detector configured to determine a time of separation of the set of switchable contact electrodes during deactivation of the power contact. The system includes a controller circuit operatively coupled to the pair of terminals and the contact separation detector. The controller circuit is configured to determine within a first observation window, a plurality of contact stick durations and an average contact stick duration. One or more additional observation windows with corresponding average contact stick durations are configured. A health assessment for the set of switchable contact electrodes may be based on a subsequent contact stick duration for a contact cycle after the first observation window and the corresponding average contact stick durations for the one or more additional observation windows.