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

The GL-12 indoor high-voltage isolation trolley and PT fuse trolley 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 transformation and distribution fields of industrial and mining enterprises.

1. Product definition and functions

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

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

Fuse trolley (RDQ trolley): usually refers to the trolley equipped with high-voltage fuses, which is often used in combination with voltage transformers (constituting PT fuse trolleys) to provide overload or short-circuit protection for equipment such as PT

Other trolleys: including circuit breaker trolleys, metering trolleys (JL trolleys), lightning arrester trolleys, etc.

2. Structural features and operation

Cabinet structure: The KYN28 switchgear is composed of two main parts: the cabinet and the extractable trolley. 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 high protection level.

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

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

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

Only when the trolley is in the test position, the earthing switch can be closed.

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

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

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

3. Key operation procedures

The following are the general operation points for isolation trolleys, PT trolleys and fuse trolleys:

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

Place the trolley: Use the transfer trolley to push the trolley to the front of the cabinet. Pull the left and right handles of the trolley 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 trolley into the secondary socket in the cabinet, and lock it with fasteners.

Confirm earthing status: Confirm that the earthing 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 trolley operation flap, use the special crank to shake clockwise, push the trolley 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 trolley removal operation:

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

Open the earthing switch (if required): If maintenance is required, open the earthing knife operation flap, use the operating handle to close the earthing 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 trolley.

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

4. Operating conditions and environment

The product must operate under the following normal environmental conditions:

Altitude: not more than 1000m (up to 2000m for special designs).

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 isolation trolley (such as GL-12/3150A), the rated voltage, transformation ratio and rated current of the fuse of the PT and fuse trolleys.

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

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

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