Core Components of the Secondary Circuit

The secondary circuit is the control center and nervous system behind the "big guy" circuit breaker. It does not directly participate in carrying high voltage and high current, but is responsible for all the low-voltage control parts that "issue commands" and "provide feedback information".

The primary circuit (main circuit) is the "aorta" responsible for transmitting high-voltage electricity, while the secondary circuit is the "brain" and "neural network" responsible for directing how this aorta works.

Core Components of the Secondary Circuit

Control Circuit

This is the core of the secondary circuit, equivalent to the "motor nerves" of a human. It's responsible for executing the opening and closing commands. When you press the "close" button, the signal is transmitted through the control circuit to the closing coil, driving the circuit breaker to close; similarly, opening commands or tripping signals from protection devices are also executed through it.

Energy Storage Circuit

Closing requires a lot of energy, which is pre-stored by the energy storage spring. The energy storage circuit is responsible for controlling the start and stop of the energy storage motor, providing tension to the spring. After energy storage is complete, the microswitch automatically cuts off the motor power and illuminates the "energy storage" indicator light.

Signal and Indication Circuit

This is the circuit breaker's "senses" and "expressions." Indicator lights (red for closed, green for open) and position switches display real-time information about the circuit breaker's status (open/closed), energy storage, and the position of the trolley, either on the cabinet panel or transmitted remotely to the control room.

Interlocking and Anti-pumping Circuit

This is the "safety mechanism" ensuring operational safety. It enforces "five protections" through electrical logic, such as preventing the circuit breaker from being accidentally pushed into the trolley while energized, or preventing operation of the circuit breaker when the trolley is not in position. The anti-pumping circuit prevents repeated "open-close" explosions caused by stuck closing signals during faults, and is crucial for circuit breaker protection.

Power Supply Circuit

This is the "energy source" for the entire secondary circuit. It stably supplies external DC (e.g., DC 110V/220V) or AC power to each secondary module, ensuring their normal operation.

Products Description

ZW7-40.5 Outdoor Vacuum Circuit Breaker with External Current Transformer (hereinafter referred to as "with CT") is a three-phase AC 50Hz, 40.5kV outdoor medium voltage equipment. It can be used for making and breaking load currents, overload currents, and short-circuit currents. The product features a rational structure and easy maintenance. It is available with optional current transformers, allowing for multiple variations and windings to meet the requirements for metering, measurement, and protection.