GL-12/630A Indoor High-Voltage Isolation Handcart, PT Handcart, Arrester Handcart

GL-12 indoor high-voltage isolating handcart and PT fuse handcart are key functional components in the KYN28 series armored removable metal-enclosed switchgear (also known as GZS1 cabinet). This series of switchgears are indoor complete power distribution devices with a rated voltage of 3.6~12kV and three-phase AC 50Hz, which are widely used in power plants, power systems and power distribution and transformation fields of industrial and mining enterprises.

1. Product definition and functions

According to different uses, the handcarts are mainly divided into the following categories, and have high interchangeability in the KYN28 cabinet:

Isolating handcart (GL cart): It is mainly used to form a reliable isolating break during system maintenance to ensure maintenance safety. Some GL carts equipped with primary components can also realize functions such as busbar connection, power measurement or protection. Voltage transformer handcart (PT cart): used to install voltage transformers to provide voltage signals for measurement, protection and metering.

Fuse handcart (RDQ cart): usually refers to a handcart installed with high-voltage fuses, which is often used in combination with voltage transformers (forming a PT fuse handcart) to provide overload or short-circuit protection for equipment such as PT

Other handcarts: including circuit breaker handcarts, metering handcarts (JL carts), arrester handcarts, etc.

2. Structural features and operations

Cabinet structure: The KYN28 switchgear is composed of two main parts: the cabinet and the extractable handcart. The cabinet is generally divided into four independent compartments: busbar compartment (A), circuit breaker compartment (C), cable compartment (D) and relay instrument compartment (B). Each compartment is separated by metal partitions, with a high protection level.

Handcart design: The handcart adopts a mid-mounted layout, and is pushed in or out by rocking a worm gear (crank), with light and flexible operation. The handcart frame is processed and assembled from steel plates and matched with the cabinet.

Interlocking and safety: The switchgear is equipped with complete "five-prevention" interlocking functions to ensure operational safety:

Only when the grounding switch is in the open position, the handcart can be moved from the test position to the working position.

Only when the handcart is in the test position, the grounding switch can be closed.

When the handcart is in the working position, the secondary plug is mechanically locked and cannot be pulled out.

When the circuit breaker is in the closed state, the handcart cannot be moved, preventing pulling out the handcart under load.

During the movement of the handcart, the isolation flap in the cabinet automatically opens and closes, effectively isolating the static contacts and preventing personnel from touching live parts.

3. Key operating procedures

The following are the general operating points for isolating handcarts, PT handcarts and fuse handcarts:

Power transmission operation (push the handcart from outside the cabinet to the working position):

Place the handcart: Use a transfer trolley to push the handcart to the front of the cabinet. Pull the left and right handles of the handcart inward at the same time to the "Ⅱ" position, push it into the test position of the switchgear, and then push the handles outward to the "Ⅰ" position to lock.

Connect the secondary wiring: Insert the secondary plug of the handcart into the secondary socket in the cabinet, and lock it with a fastener.

Confirm grounding status: Confirm that the grounding switch in the cabinet is in the open state. Test operation: Carry out necessary closing and opening operation tests on the relevant loops at the test position to confirm that the control signals are correct.

Push to the working position: Open the handcart operation flap, use the special crank to shake clockwise to push the handcart to the working position (there will be a "click" locking sound when in place), take out the crank and close the flap.

Power outage and handcart removal operation:

Retreat to the test position: Open the handcart operation flap, use the crank to shake counterclockwise to retreat the handcart to the test position (there will be a "click" sound when in place).

Open the grounding switch (if necessary): If maintenance is required, open the grounding knife operation flap, use the operating handle to close the grounding switch clockwise, and confirm that it is in the closed state.

Disconnect the secondary connection: Open the circuit breaker compartment door and pull out the secondary plug of the handcart.

Pull out the handcart: Pull the left and right handles of the handcart inward at the same time to the "Ⅱ" position, and you can pull the handcart out of the cabinet.

4. Operating conditions and environment

The product must operate under the following normal environmental conditions:

Altitude: not more than 1000m (special design can reach 2000m).

Ambient temperature: not higher than +40℃, daily average not higher than +35℃, not lower than -10℃ (or -25℃).

Relative humidity: daily average not more than 95%, monthly average not more than 90%.

Others: Places without fire, explosion, serious pollution, chemical corrosion and frequent severe vibration.

5. Matters needing attention in selection and configuration

Rated parameter confirmation: Clarify the key parameters such as the rated current of the isolating handcart (such as GL-12/3150A), the rated voltage, transformation ratio and rated current of the fuse of the PT and fuse handcarts.

Scheme and function: Select the corresponding configured handcart type according to the needs of the power distribution system (such as busbar connection, metering, protection).

Interchangeability: Similar handcarts have extremely high interchangeability in the KYN28 cabinet, which is convenient for maintenance and spare parts management.

Installation and grounding: Ensure reliable grounding of the cabinet during installation, and there is a dedicated grounding busbar running through each cabinet in the cabinet