1、 Scope of application

TXJQ3Hand pulled isolation switch(also known asHook type isolation switch）Suitable for mixed circuits of resistors and inductors with AC 50/60Hz, rated voltage below 230-400V, and rated current between 63A and 125A, mainly used for connecting or disconnecting circuits under no-load conditions, and for connecting or isolating lines and power sources. Especially suitable for effectively isolating the power supply and preventing accidental closing during line maintenance to ensure the safety of maintenance personnel, the hook type isolation switch is widely used in the supporting products of the national rural power grid meter box, replacing the old type knife switch, making installation more convenient and the appearance more beautiful.
Isolation switch is the most commonly used type of high-voltage switchgear, as the name suggests, it plays an isolation role in the circuit. Its working principle and structure are relatively simple, but due to its large usage and high reliability requirements, it has a significant impact on the design, establishment, and safe operation of substations and power plants. The main feature of a knife switch is that it has no arc extinguishing ability and can only open and close circuits without load current.

2、 Model and specifications

3、 Operating environment and working conditions

◆ Surrounding air temperature: -5 degrees Celsius to+40 degrees Celsius, with an average temperature not exceeding+35 degrees Celsius.
◆ Altitude: not exceeding 2000m.
Relative atmospheric temperature:+40 degrees, not exceeding 50%, and 90% in the wettest month.
The pollution level is Level II.
◆ Usage category: AC-22A.
Installation conditions: The hand pulled isolation switch is normally installed vertically (with the upper end as the incoming line), with the handle pushed upwards to close and the contacts connected. If it is pulled downwards, the contacts will disconnect, and then the handle can be tightened to avoid accidental closing.
The installation form adopts TH35-7.5 steel installation rail installation.

4、 Structural characteristics

Hand pulled isolation switchIt is directly operated by a handle, with a modular and standardized guide rail installation structure, especially suitable as a matching isolation switch component for terminal combination electrical appliances. Due to the reasonable contact form adopted by the dynamic and static contacts, the conductivity and stability are good. The insulated handle and the moving contact are riveted together, and the moving contact can be easily opened by pulling the handle and is clearly visible, without the need for a separate closed position indicator. And because the handle is attached with a ring iron, it can be tightly hooked with the lower end to avoid accidental closing, greatly improving safety and ensuring the operation safety of maintenance personnel. It is particularly suitable for non professionals to use and operate.

5、 Main technical parameters

Rated current (A)	32, 63, 100
Polar number (P)	1. 2, 3, 4
Rated working voltage (V)	Single phase 230
	Three phase 400
Rated short-time withstand current	12le， The power on time is 1 second
Rated short-time making capacity	20le， The power on time is 0.1s
Rated connection and disconnection capacity	3le, 1.05Ue, cos φ=0.65
Operational performance	No load 8500 times, load 1500 times, a total of 10000 times

6、 Installation and use

■Hook type isolation switchIt should be installed vertically, with the upper static contact terminal connected to the power supply, so that the moving contact is not electrified when disconnected, to ensure personal safety during manual operation.
■Hand pulled isolation switchUnder normal circumstances, it is not allowed to operate with a load when closing and opening. After disconnection, the ring clamp fitted on the handle should be tightly fastened to the corresponding hook at the lower end of the switch to prevent accidental closing and ensure the safety of maintenance personnel.

7、 Precautions

■Hook type isolation switchIt is not advisable to repeatedly turn on and off large overloads, nor to frequently turn on and off normal working currents. It is also important to avoid forcefully pushing and pulling switches to avoid accidents and shorten the product's service life.
■Hand pulled isolation switchThere is no arc extinguishing chamber inside, and it is not allowed to be used to disconnect fault currents. If necessary, users can choose the appropriate combination of fuses to achieve high load and short-circuit breaking capacity (the specific breaking capacity depends on the breaking capacity of the selected fuse)

8、 Appearance and installation dimensions

9、 Ordering Notice

When placing an order, please indicate the following points:
Product model and name: such as TXJQ3Hand pulled isolation switch/Hook type isolation switch
Rated current: 100A.
Polar number: 3P
Order quantity: such as 77777 pieces.
Example of ordering: TXJQ3Hook type isolation switch， 63A，2P， 2560 pieces.

10、 Understand the isolation switch

The main function of isolation switch
① After disconnection, establish a reliable insulation gap and separate the equipment or lines that need maintenance from the power supply with a clear disconnect point to ensure the safety of maintenance personnel and equipment.
② According to operational needs, switch the circuit.
③ It can be used to separate and combine small currents in power lines, such as the charging current of bushings, busbars, connectors, and short cables, the capacitance current of switch voltage equalization capacitors, the circulating current during double busbar switching, and the excitation current of voltage transformers.
④ According to the specific situation of different structural types, it can be used to separate and combine the no-load excitation current of a certain capacity transformer.

High voltage isolating switches can be divided into outdoor high-voltage isolating switches and indoor high-voltage isolating switches according to their installation methods. Outdoor high-voltage isolation switch refers to a high-voltage isolation switch that can withstand the effects of wind, rain, snow, dirt, condensation, ice, and thick frost, and is suitable for installation on terraces. According to the different insulation pillar structures, it can be divided into single column isolation switches, double column isolation switches, and three column isolation switches. Among them, the single column knife switch directly uses the vertical space as the electrical insulation for the fracture under the overhead busbar. Therefore, it has obvious advantages such as saving floor space, reducing the number of connecting wires, and having a particularly clear opening and closing state. In the case of ultra-high voltage transmission, the use of single column knife switches in substations has a more significant effect on saving floor space. It is mainly suitable for low-voltage terminal distribution systems in residential and building areas. Main function: Load breaking and connecting lines

Characteristics of isolation switch
① During electrical equipment maintenance, provide an electrical interval and a clearly visible disconnection point to ensure the personal safety of maintenance personnel. ② Isolation switches cannot be operated with load: they cannot be operated with rated load or high load, and cannot separate or close load current and short-circuit current. However, those with arc extinguishing chambers can be operated with low load and no-load lines. ③ During general power transmission operations: first close the isolation switch, then close the circuit breaker or load switch; When disconnecting the isolating switch, first disconnect the circuit breaker or load switch, and then disconnect the isolating switch. ④ When selecting, it is no different from other electrical equipment, as it must meet the requirements of the usage scenario in terms of rated voltage, rated current, dynamic stability current, thermal stability current, etc. The function of an isolation switch is to disconnect the circuit from no-load current Ensure that the equipment under maintenance has a clear disconnection point from the power supply to ensure the safety of maintenance personnel. Without a dedicated arc extinguishing device, the isolation switch cannot cut off the load current and short-circuit current. Therefore, the isolation switch must be operated only when the circuit is disconnected by the circuit breaker.

Application of isolation switch
① Used to isolate power sources, disconnect high-voltage maintenance equipment from live equipment, so that there is a clearly visible disconnection point between them.
② The isolation switch and circuit breaker are coordinated to perform switching operations according to the needs of the system operation mode, in order to change the wiring mode of the system operation.
③ Used to connect or disconnect small current circuits. Generally, a set of isolation switches is installed on both sides of the circuit breaker, with the purpose of isolating the circuit breaker from the power supply and forming a clear disconnection point; Because the original circuit breaker used an oil circuit breaker, which requires frequent maintenance, there should be clear disconnection points on both sides to facilitate maintenance; In general, the outgoing cabinet is powered downwards from the upper busbar through the switch cabinet. A set of isolation switches is required in front of the circuit breaker to isolate it from the power supply. However, sometimes there is also a possibility of incoming power behind the circuit breaker, such as through the reverse transmission of other loops, capacitors, and other devices. Therefore, a set of isolation switches is also required behind the circuit breaker.

Isolation switches are mainly used to reliably isolate the parts of high-voltage distribution equipment that require power outage from the live parts, in order to ensure the safety of maintenance work. The contacts of the isolation switch are all exposed in the air and have obvious disconnection points. The isolation switch does not have an arc extinguishing device, so it cannot be used to cut off load current or short-circuit current. Otherwise, under high voltage, the disconnection point will generate a strong arc, which is difficult to extinguish on its own, and may even cause arcing (relative to ground or phase to phase short circuit), burn equipment, and endanger personal safety. This is a serious accident called "pulling the isolation switch with load". Isolation switches can also be used to switch certain circuits and change the operating mode of the system. For example, in a dual bus circuit, an isolation switch can be used to switch the operating circuit from one bus to another. At the same time, it can also be used to operate circuits with small currents