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 scalable power tap off system is provided for a power distribution system. The system can have components including a line-side connector assembly for connecting to an upstream power supply, a load-side connector assembly for connecting to downstream load(s), and a draw-out circuit breaker assembly connected between the line-side and load-side connector assemblies. The system also includes a shutter assembly having a movable shutter for proving a barrier to prevent access to at least line-side electrical components on the breaker assembly when the breaker assembly is in the racked-out state, and insulated interconnect buses for electrically connecting the line-side connector assembly and the load-side connector assembly to the breaker assembly. An enclosed compartment is provided to house the load-side connector assembly in isolation from other components and allows access to the load-side connector assembly when the breaker assembly is in a racked-out state or the load-side connector assembly is de-energized.

A scalable power tap off system is provided for a power distribution system. The system can have components including a line-side connector assembly for connecting to an upstream power supply, a load-side connector assembly for connecting to downstream load(s), and a draw-out circuit breaker assembly connected between the line-side and load-side connector assemblies. The system also includes a shutter assembly having a movable shutter for proving a barrier to prevent access to at least line-side electrical components on the breaker assembly when the breaker assembly is in the racked-out state, and insulated interconnect buses for electrically connecting the line-side connector assembly and the load-side connector assembly to the breaker assembly. An enclosed compartment is provided to house the load-side connector assembly in isolation from other components and allows access to the load-side connector assembly when the breaker assembly is in a racked-out state or the load-side connector assembly is de-energized.

A system and method are provided for coordinating the installation and removal a motor control center subunit with the power connection and interruption thereof. A system of interlocks and indicators causes an operator to install a motor control center subunit into a motor control center, and connect supply and control power thereto, in a particular order. Embodiments of the invention may prevent actuation of line contacts of the bucket, and shield the line contacts, until the bucket is fully installed in the motor control center. Other embodiments also prevent circuit breaker closure until the line contacts are engaged with a bus of the motor control center.

A switchboard is provided having a rotating shutter structure that comprises: a switchboard body that is provided with a circuit breaker chamber into which a circuit breaker is inserted, and an open hole formed in the rear surface to expose a conductor part of a bushing assembly to the circuit breaker chamber; a shutter part that is rotatably installed in the switchboard body and opens/closes the open hole by rotating; and an operation unit that is installed in the switchboard body and rotates the shutter part when the circuit breaker is inserted into the circuit breaker chamber.

A switchboard is provided having a rotating shutter structure that comprises: a switchboard body that is provided with a circuit breaker chamber into which a circuit breaker is inserted, and an open hole formed in the rear surface to expose a conductor part of a bushing assembly to the circuit breaker chamber; a shutter part that is rotatably installed in the switchboard body and opens/closes the open hole by rotating; and an operation unit that is installed in the switchboard body and rotates the shutter part when the circuit breaker is inserted into the circuit breaker chamber.

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 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 safety shutter of the present disclosure comprises: a base unit; a shutter unit; and a cam unit. The base unit is coupled to a cradle of an air circuit breaker, and a terminal connected to a main circuit passes through the base unit. The shutter unit is coupled to the base unit so as to be spaced apart at a predetermined interval, and accommodates the terminal in the space between the shutter unit and the base unit. The cam unit extends from the base unit and penetrates the shutter unit. The shutter unit deactivates insulation by exposing the terminal in the direction of the air circuit breaker when the air circuit breaker is inserted in the direction of the base unit.