Abstract: Electrical circuit breakers in an electrical panelboard are equipped with tie-down devices to secure the circuit breakers to the panelboard. Each circuit breaker includes a standard housing or case having a raised portion that forms a pair of end walls and a slot at the base of each of the end walls. The panelboard includes mounts for attaching the tie-down devices to the panelboard. Each tie-down device includes (1) a breaker-attachment portion adapted to be mounted on the circuit breaker housing around the raised portion and having a pair of mounting hooks adapted to fit into the slots for attaching the tie-down device to the circuit breaker housing, and (2) a panelboard attachment portion extending beyond the circuit breaker housing for attachment to the panelboard mount.

Abstract: A highly accurate current sensing transformer, such as an external neutral current transformer (ENCT), accommodates a wide range of loads. The ENCT includes a housing, first and second terminals each having an end portion extending from and external to the housing, a conductor for carrying a current to be measured, and a current sensor having an aperture for receiving the conductor and having a central axis. The conductor joins the first and second terminals to form a current path that passes through the aperture. Increased accuracy is achieved by arranging the conductor such that a portion thereof passing through the aperture forms a substantial angle relative to the central axis, such that the entry angle of the current path via the conductor through the aperture of the current sensor of the ENCT matches an entry angle of a conductor through an aperture of a current sensor in the electronic trip unit to which the ENCT is attached.

Abstract: Electrical circuit breakers in an electrical panelboard are equipped with tie-down devices to secure the circuit breakers to the panelboard. Each circuit breaker includes a standard housing or case having a raised portion that forms a pair of end walls and a slot at the base of each of the end walls. The panelboard includes mounts for attaching the tie-down devices to the panelboard. Each tie-down device includes (1) a breaker-attachment portion adapted to be mounted on the circuit breaker housing around the raised portion and having a pair of mounting hooks adapted to fit into the slots for attaching the tie-down device to the circuit breaker housing, and (2) a panelboard attachment portion extending beyond the circuit breaker housing for attachment to the panelboard mount.

Abstract: A highly accurate current sensing transformer, such as an external neutral current transformer (ENCT), accommodates a wide range of loads. The ENCT includes a housing, first and second terminals each having an end portion extending from and external to the housing, a conductor for carrying a current to be measured, and a current sensor having an aperture for receiving the conductor and having a central axis. The conductor joins the first and second terminals to form a current path that passes through the aperture. Increased accuracy is achieved by arranging the conductor such that a portion thereof passing through the aperture forms a substantial angle relative to the central axis, such that the entry angle of the current path via the conductor through the aperture of the current sensor of the ENCT matches an entry angle of a conductor through an aperture of a current sensor in the electronic trip unit to which the ENCT is attached.

Abstract: An electrical contact for use in an electrical switching device is provided having low contact resistance, high wear resistance and high anti-weld characteristics. The contact includes a material composition of between 0.2 and 8% by weight Gr, between 10 and 90% by weight W and the remaining mixture consisting of Ag. The contact is manufactured using a process which yields a unique microstructure characterized by not having an interconnected Gr network around the Ag thereby providing a strong Ag to Ag bond. This process includes the steps of adding the appropriate amounts of Ag, W and Gr powder material together, blending together under low shear conditions to provide a homogenous powder mixture while prohibiting the Gr from smearing onto the Ag, pressing the material mixture to form a contact, and then sintering and coining the contact.