I. Overview
GW4-126GW (D) outdoor AC high voltage isolation relationship double column three-phase AC 50Hz outdoor high voltage switchgear is used in power systems with a voltage of 110KV, for the purpose of closing circuits with and without voltage load, and for the electrical isolation of high-voltage busbars, circuit breakers and other electrical equipment under maintenance from live high-voltage lines. The anti fouling isolation switch can meet the requirements of users in heavily polluted areas and effectively solve the problem of pollution flashover that occurs during the operation of the isolation switch.
The combination of GW4 series and CJ5, CJ6, CJ2, CJ11A series electric operating mechanisms is particularly suitable for the needs of long-distance separation and combination in the fields of power systems and electrified railways.

GW4-126GW (D) outdoor high-voltage isolation switches have the following varieties:
1) Divided by the presence or absence of a grounding switch: ungrounded, single grounded (left and right grounded), and double grounded;
2) Grounding switches are classified into types I, II, and III based on their ability to withstand short-circuit currents;
3) Divided by usage area: ordinary type, anti fouling type, anti fouling type, and high-altitude type.
This series of products meets the requirements of national standards and IEC standards, with good seismic resistance and the ability to meet the requirement of a seismic intensity of 9 degrees.

Note: GW4-126 isolating switches are produced according to the following requirements:
1. Improve the non welding type of hoop connection;
2. Level 3 pollution prevention, creepage distance ≥ 3150mm;
3. Equipped with alternating hot-dip galvanized horizontal connecting rods, with a pole spacing of 2m;
4. Hot dip galvanizing of components;
5. Conductive copper tube flexible connection type;
6. The middle contact of the conductive part is a self operated contact finger, and there is no current passing through the spring;
7. The rotating part is equipped with a self-lubricating sleeve.

2、 Main technical parameters

(Note: Single grounding is divided into two types: left grounding and right grounding. Generally, right grounding is supplied.)

3、 Usage conditions
1. The altitude shall not exceed 1000m, and the plateau type shall not exceed 4000m;
2. Environmental temperature: -40 ℃ to+40 ℃;
3. Wind speed not exceeding 35m/s;
4. Earthquake intensity: 8 degrees;
5. Ice thickness: ≤ 10mm;
6. Anti pollution products are suitable for polluted areas;
7. Not suitable for places with flammable substances, explosion hazards, chemical corrosion, and severe vibrations.
Explanation: When the above environmental conditions cannot meet the usage requirements, it shall be resolved through negotiation between the user and the manufacturer.
4、 Structure
The GW4 series isolating switch has reliable performance, simple structure, flexible installation method, easy maintenance, wide applicability, and strong versatility. If equipped with a transmission box, the opening and closing operation is more flexible, lightweight, accurate and reliable; When an electromagnetic lock is attached, it can effectively achieve electrical interlocking between the isolation switch, grounding switch, and circuit breaker to prevent misoperation.
The GW4-126 outdoor isolation switch is a three-phase high-voltage electrical appliance composed of three independent single pole isolation switches, and is also a basic unit derived from other structures. It is referred to as a common isolation switch below.
The GW4-126D outdoor isolation switch is made by adding a grounding knife to the ordinary isolation switch, which is divided into single grounding and double grounding types, hereinafter referred to as the grounding type isolation switch.
The GW4-126 (DW) outdoor isolation switch is made by replacing the ordinary rod type post insulator with an anti fouling rod type post insulator based on the ordinary (grounding) isolation switch, and is suitable for polluted areas.
1. Isolation switch structure
This isolation switch is a double column horizontal rotary structure, as shown in Figure 1 for its external structure.
Each set of isolation switches consists of three independent single poles, each consisting of a base, an insulating pillar, and a conductive part. Each pole isolation switch has two insulation pillars fixed on the bearing seats at both ends of the base (Figure 2), connected by connecting rods. Each insulation pillar can rotate horizontally at a 90 ° angle, and is equipped with a soft connection conductive terminal block (Figure 3) and left and right contacts (Figure 4). The left and right contacts make contact between two insulated pillars through a conductive tube. The isolation switch bearing seat is shown in Figure 2
The conductive terminal block for the soft connection of the isolation switch is shown in Figure 3
The left and right contacts of the isolation switch are shown in Figure 4
The material of the conductive circuit components in the main circuit is copper, and when the current level is 630A, the surface of the conductive components is tin plated; When the current level is above 1250A, the contact surface of the conductive component is silver plated.
The middle contact is a "handshake" structure, which adopts patented technology for pressing the contact finger blade gasket. It is a high-pressure, self-cleaning type, and the contact pressure of the contact finger remains constant for a long time. The contact finger spring has no current passing through, and it operates safely and reliably for a long time.
The structural types, bases, post insulators, and other components of products with different current specifications are the same, except for slight differences in the main electrical circuit
2. Structure of grounding switch
The static contact of the grounding switch is fixed on the conductive tube of the isolation switch, and the moving contact is installed at the end of the aluminum tube of the grounding switch on the base.
3. Mechanical interlocking of isolation switch and grounding switch
The mechanical interlocking between the isolating switch and the grounding switch is achieved through an interlocking disc. When the isolating switch is in the closed position, the fan-shaped interlocking disc of the grounding switch rotating shaft restricts the closing of the grounding switch.
When the grounding switch is in the closed position, the grounding switch related locking plate is inserted into the fan-shaped interlocking plate of the isolating switch, preventing the isolating switch from closing.
4. Structure of the operating mechanism
The isolation switch can be equipped with CS14G manual mechanism (Figure 5) or CJ5, CJ6 electric mechanism and CJ12A-G maintenance free electric mechanism. The grounding switch can be equipped with CS14G manual mechanism, and its operating handle is horizontally rotating with a rotation angle of 180 °.
CJ5, CJ6 electric mechanisms and CJ12A-G maintenance free electric mechanisms can be found in their respective manuals.
CS14G manual mechanism is shown in Figure 5