A switchgear system may include a switchgear frame, a truck and circuit breaker mounted thereon. A drive mechanism is mounted on the switchgear frame and configured to rack the circuit breaker into a) a first connected position where the primary and secondary circuits are electrically connected, b) a second test position where the primary circuit is electrically disconnected and secondary circuit connected, and c) a third disconnected position where the primary and secondary circuits are electrically disconnected, wherein said drive mechanism comprises a drive chain and shuttle configured to engage the truck and rack and fix the circuit breaker into the first connected position.

A contact arm assembly includes a contact arm defining a central axis and having a first end configured for electrical connection with a pole of a circuit breaker and a second end having a distal end defining a shoulder and an engagement that protrudes from the contact arm proximal to the shoulder. A plurality of contact fingers are mounted circumferentially on the second end of the contact arm and configured to electrically engage a primary circuit contact. Each contact finger has a body with a depression that receives the engagement for electrical contact.

A contact arm assembly includes a contact arm defining a central axis and having a first end configured for electrical connection with a pole of a circuit breaker and a second end having a distal end defining a shoulder and an engagement that protrudes from the contact arm proximal to the shoulder. A plurality of contact fingers are mounted circumferentially on the second end of the contact arm and configured to electrically engage a primary circuit contact. Each contact finger has a body with a depression that receives the engagement for electrical contact.

A medium-voltage switchgear system includes a three-phase circuit breaker having first, second and third single-phase vacuum interrupters connected between respective first, second and third single-phase inputs and first, second and third single-phase outputs. Magnetic actuators are connected to first, second and third single-phase vacuum interrupters, which are configured to receive an interrupt signal and in response, actuate the respective vacuum interrupter connected thereto into an open circuit condition. A controller circuit is connected to each of the first, second and third magnetic actuators and generates an interrupt signal in response to a detected single-phase overcurrent or fault on a single-phase circuit and interrupt that single-phase circuit on which the single-phase overcurrent or fault occurred and maintain power on the remaining two single-phase circuits over which a single-phase overcurrent or fault was not detected.

A switchgear system includes a switchgear frame having an interior compartment and front opening and containing therein at least one electrical switchgear component. A truck carries an electrical component and is supported for movement on the switchgear frame. A drive mechanism connects the truck and is configured to rack in the truck into an electrically connected position with the at least one electrical switchgear component, rack out the truck from the electrically connected position into an electrically disconnected position, and rotate the truck upward from its disconnected position into a rotated position to allow operator access through the front opening to the at least one electrical component.

A switchgear system includes a switchgear frame having an interior compartment and front opening and containing therein at least one electrical switchgear component. A truck carries an electrical component and is supported for movement on the switchgear frame. A drive mechanism connects the truck and is configured to rack in the truck into an electrically connected position with the at least one electrical switchgear component, rack out the truck from the electrically connected position into an electrically disconnected position, and rotate the truck upward from its disconnected position into a rotated position to allow operator access through the front opening to the at least one electrical component.

A switchgear system may include a switchgear frame and a truck carrying a circuit breaker and supported for linear movement on the switchgear frame. A drive mechanism may rack in the truck and the circuit breaker is in electrical connection with primary circuit contacts, and may rack out the truck and the circuit breaker is electrically disconnected from the primary circuit contacts. As the drive mechanism racks in the circuit breaker, a shutter linkage moves a shutter opened, and as the drive mechanism racks out the circuit breaker, the shutter linkage moves the shutter closed over the primary circuit contacts.

A switchgear system may include a switchgear frame and a truck carrying a circuit breaker and supported for linear movement on the switchgear frame. A drive mechanism may rack in the truck and the circuit breaker is in electrical connection with primary circuit contacts, and may rack out the truck and the circuit breaker is electrically disconnected from the primary circuit contacts. As the drive mechanism racks in the circuit breaker, a shutter linkage moves a shutter opened, and as the drive mechanism racks out the circuit breaker, the shutter linkage moves the shutter closed over the primary circuit contacts.

A switchgear system includes a switchgear frame and a truck carrying a circuit breaker, which includes a breaker housing, a fixed electrical contact and a movable electrical contact mounted within the breaker housing, an actuator piston connected to the movable electrical contact, and a drive assembly coupled to the actuator piston. A sensor circuit is mounted on the switchgear frame under the truck and aligned with the circuit breaker and configured to acquire displacement data of the actuator piston when in a contact testing position. A controller is coupled to the sensor circuit and configured to receive the displacement data and determine electrical contact erosion within the circuit breaker.

A switchgear system includes a switchgear frame and a truck carrying a circuit breaker, which includes a breaker housing, a fixed electrical contact and a movable electrical contact mounted within the breaker housing, an actuator piston connected to the movable electrical contact, and a drive assembly coupled to the actuator piston. A sensor circuit is mounted on the switchgear frame under the truck and aligned with the circuit breaker and configured to acquire displacement data of the actuator piston when in a contact testing position. A controller is coupled to the sensor circuit and configured to receive the displacement data and determine electrical contact erosion within the circuit breaker.