An electrical unit includes a contactor having a housing member, a first terminal, a second terminal, and/or a contact member disposed in the housing member and configured to selectively electrically connect the first terminal and the second terminal. The electrical unit may include a cooling member connected to the housing member, a first bus bar connected to the cooling member and the first terminal, and/or a second bus bar connected to the cooling member and the second terminal. The cooling member may be configured to dissipate heat that is generated via electrical current flowing through the contact member.

A method and system for monitoring a heating arrangement includes applying a first polarity voltage to a heater of the heating arrangement, detecting a first polarity heating leakage current, applying a second polarity voltage to the heating arrangement, detecting a second polarity heating leakage current, and determining health of the heating arrangement via the first polarity heating leakage current and the second polarity heating leakage current.

A method and system for monitoring a heating arrangement includes applying a first polarity voltage to a heater of the heating arrangement, detecting a first polarity heating leakage current, applying a second polarity voltage to the heating arrangement, detecting a second polarity heating leakage current, and determining health of the heating arrangement via the first polarity heating leakage current and the second polarity heating leakage current.

A cooling apparatus for a medium voltage or high voltage switchgear includes an evaporator, a fluid conduit, and a condenser. The evaporator is configured to surround at least part of a current carrying contact. The fluid conduit fluidly connects the evaporator to the condenser. A section of the fluid conduit is formed within the evaporator and is electrically insulating and is configured such that fluid can contact an outer surface of the current carrying contact. The cooling apparatus is configured such that in use a working fluid in the evaporator is heated to a vapour state, and the vapour is transferred by the fluid conduit to the condenser. The vapour in the condenser is condensed to the working fluid. The condensed working fluid is passively returned via the fluid conduit to the evaporator.

A cooling apparatus for a medium voltage or high voltage switchgear includes an evaporator, a fluid conduit, and a condenser. The evaporator is configured to surround at least part of a current carrying contact. The fluid conduit fluidly connects the evaporator to the condenser. A section of the fluid conduit is formed within the evaporator and is electrically insulating and is configured such that fluid can contact an outer surface of the current carrying contact. The cooling apparatus is configured such that in use a working fluid in the evaporator is heated to a vapour state, and the vapour is transferred by the fluid conduit to the condenser. The vapour in the condenser is condensed to the working fluid. The condensed working fluid is passively returned via the fluid conduit to the evaporator.

An electrical connector device for connecting a bus bar to one or more electrical contacts of a circuit interrupting device is provided. The electrical connector device includes an electrically conductive body having a first end configured to engage the one or more electrical contacts of the circuit interrupting device, and a second end configured to engage the bus bar. The electrically conductive body includes a central portion and an outer portion, and has a cavity defined therein between the central portion and the outer portion. The electrical connector device also includes an evaporative heat transfer device including a wick and a working fluid each disposed within the cavity defined within the electrically conductive body. The heat transfer device is configured to facilitate heat transfer from the first end of the electrically conductive body to the second end.

An electrical connector device for connecting a bus bar to one or more electrical contacts of a circuit interrupting device is provided. The electrical connector device includes an electrically conductive body having a first end configured to engage the one or more electrical contacts of the circuit interrupting device, and a second end configured to engage the bus bar. The electrically conductive body includes a central portion and an outer portion, and has a cavity defined therein between the central portion and the outer portion. The electrical connector device also includes an evaporative heat transfer device including a wick and a working fluid each disposed within the cavity defined within the electrically conductive body. The heat transfer device is configured to facilitate heat transfer from the first end of the electrically conductive body to the second end.

A relay has a case, a first fixed terminal including a first fixed contact, a second fixed terminal including a second fixed contact, a movable touch piece including a first movable contact that is disposed facing the first fixed contact and a second movable contact that is disposed facing the second fixed contact, the movable touch piece being disposed in the case and disposed so as to be movable in a direction in which the first movable contact and the second movable contact come into contact with the first fixed contact and the second fixed contact and in a direction in which the first movable contact and the second movable contact separate from the first fixed contact and the second fixed contact. The first fixed terminal includes a first contact support disposed in the case and configured to support the first fixed contact.

A circuit breaker arrangement includes a housing, a contact seated in the housing, and a lead in electrical communication with the at least one contact and disposed outside the housing. The circuit breaker arrangement includes a heat sink in thermal communication with the lead to transfer heat between the contact and the lead.

A contactor assembly post is provided. The contactor assembly post includes a first portion electrically connected to an external bus bar at an exterior of an electrical contactor housing, a second portion electrically connected to an internal bus bar at the exterior of the electrical contactor housing, a third portion and fins. The internal bus bar is configured to extend into an interior of the electrical contactor housing to be electrically coupled to another internal bus bar. The third portion extends transversely between the first and second portions. The fins extend transversely from multiple points defined along a longitudinal axis of the third portion.