22KV Medium Voltage Switchgear Electrical Mechanism

In modern medium-voltage power distribution networks, ring main units (RMUs) are widely used to provide highly available and reliable power supply. One of the key components of a RMU is its circuit breaker operating mechanism, which must be able to perform closing and opening operations quickly and safely.

The 22kV Medium Voltage Switchgear Electrical Mechanism is designed specifically for incoming circuit applications of gas-insulated or air-insulated RMUs. It is an energy-storage operating mechanism employing two independent spring systems: a tension spring for closing and a compression spring for opening.

The closing spring stores energy by rotating a handle (manually) or by being driven by a motor; once the closing latch is triggered, the spring immediately releases the energy.

During the closing operation, the opening spring simultaneously stores energy and then remains in a standby state, ready to respond to subsequent opening commands.

Key features include

Both of the manual and electric operation type for charging and tripping.

Separate buttons with protective covers mounted on the panel of the, preventing dust ingress and inadvertent operation.

Interlocking capability when combined with an isolator mechanism, ensuring safe sequence control.

Auto‑reclosing function (when required) and anti‑pumping logic to avoid multiple operations.

The product complies with the relevant standard GB 1984‑2014 (high‑voltage AC circuit breakers) and GB/T 1985‑2023 (high‑voltage AC disconnectors and earthing switches).

Model

What are the working principles and operating mechanisms of this organization?

The working principle of 22KV Medium Voltage Switchgear Electrical Mechanism is according to the storage and rapid release of mechanical energy.

Energy Storage (Charging)

Manual charging: A dedicated handle is inserted into the charging shaft located at the lower right part of the mechanism. Rotating the handle clockwise turns the shaft, which tensions the closing spring via a gear or cam system. When the spring passes the "over‑center" point, it latches in the charged position, accompanied by an audible "click" and a visual indicator (e.g., a rotating shaft that activates a microswitch).

Electric charging: When control voltage is applied, the electric motor automatically drives the charging mechanism until the closing spring is fully tensioned. At that point, the motor circuit is interrupted by a microswitch, and the spring remains latched, ready for closing.

Closing Operation

Manual closing: Pressing the green button (protected by a transparent cover on the panel) mechanically releases the closing latch. The tension spring quickly releases energy, drives the spindle to rotate, and moves the circuit breaker contacts to the closed position. At the same time, this action will compress the opening spring, storing energy for the next opening.

Electric closing: Energizing the closing coil (solenoid) pulls an armature that releases the closing latch, producing the same mechanical action as manual closing. After closing, the mechanism may immediately begin re‑charging the closing spring (if auto‑reclosing is configured), but an interlock prevents a second closing until the breaker has been opened and the proper conditions are met.

Opening Operation

Manual opening: Pressing the red button releases the opening latch. The compression of the actuator opens the spring extension, driving the operating mechanism to separate the contacts.

Electric opening: energize the opening coil (electromagnet) of the operating mechanism, trigger the opening lock, release the opening spring, and disconnect the circuit of the circuit breaker.

This operating mechanism has a mechanical interlock device that prevents the occurrence of simultaneous closing and opening commands, and also ensures that the isolation switch (if present) is in the correct position before the circuit breaker can be operated..

Operation Instructions

Preliminary Checks

Ensure the mechanism is correctly mounted on the switchgear and that all secondary wiring (for electric operation) is accurate and secure.

Verify that the panel‑mounted buttons (green for close, red for open) are fitted with their protective covers and that the operation indicators (e.g., "charged/discharged") are visible.

Charging (Energy Storage)

Manual: Insert the operating handle into the charging socket (lower right side). Rotate clockwise steadily until a distinct "click" is heard and the charging indicator shows "charged". Remove the handle.

Electric: Apply control power to the mechanism. The motor will automatically run until the spring is fully charged and stop. Then confirm that the 'charged' indicator light is on.

Closing the Circuit Breaker

Manual: Lift the protective cover of the green button and press it firmly. The breaker should close, and the "closed" position indicator should appear. The opening spring is now automatically charged.

Electric: Send a closing command (e.g., from a remote control or protection relay) to the closing coil. The breaker closes; verify position indication.

Opening the Circuit Breaker

Manual: Lift the protective cover of the red button and press it firmly. The breaker opens; confirm the "open" indication.

Electric: Send an opening command to the opening coil. The breaker opens.

After Operation

After a closing operation, the mechanism may automatically re‑charge the closing spring if the motor supply is present. This prepares the breaker for a subsequent close‑open cycle.

Always observe the status indicators and respect any interlock conditions (e.g., isolator position) before operating.

The spring‑operated mechanism provides a robust, reliable, and safe controlling for circuit breakers in RMU incoming lines. this 22KV Medium Voltage Switchgear Electrical Mechanism

combination of tension and compression springs, manual and electric operation, and built‑in interlocks meets the requirements of modern distribution networks. This mechanism mechanical life is over 10, 000 operations and complies with international standards, which can ensure long‑term performance and operational safety.

Appearance and dimensions

Applications

Medium-voltage RMUs, GIS, and AIS incoming lines.

Renewable energy projects: wind farms, solar PV stations.

Railway and metro projects requiring high operational safety.

Industrial and municipal distribution networks.

Project References

Guojiawan 110kV – 35kV Gas-insulated Switchgear – Wind farm project.

Ayni Gold Mine 110kV Substation, Tajikistan – High-reliability power distribution.

Maqu 200MW Pasture-Solar Hybrid PV Project – Auto-reclosing mechanism applied.

Why Choose Cotenele?

• Expert Manufacturer: Over 6 years of experience in 12kV–40.5kV switchgear core components.

• Certified Quality: ISO9001 / ISO14001 / ISO18001; products tested by national authorities.

• Proven Track Record: Supplying medium-voltage switchgear mechanisms for domestic and international wind, solar, and railway projects.

• Innovative Technology: Continuous development of RHSV series eco-friendly gas-insulated switchgear mechanisms ensures stability and safety.

Cotenele is committed to delivering high-reliability, long-life, and safe switchgear mechanisms, meeting the requirements of modern distribution networks and renewable energy applications.

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