High Voltage Isolating Switch Instructions

Environmental conditions
1. Altitude: not more than 1000m;
2. Ambient air temperature: -30 +40;
3. Ambient relative humidity: daily average not more than 95%;
4. Monthly average not more than 90%. Earthquake intensity not more than 8;
5. Safe place: no fire, flammable, explosive, serious pollution, chemical corrosion and severe vibration place.
Technical performance
High Voltage Isolator Switch has no arc extinguishing device and cannot be operated with load.
For 10KV disconnector, under normal circumstances, its allowed operating range is:
1. Open and close voltage transformer and lightning arrester.
2. Open and close the charging current of busbar.
3. Open and close the no-load transformer with excitation current not exceeding 2A and the no-load line with capacitance current not exceeding 5A.
The old transformers from the 1950s and 1960s had large no-load current meters, so it was stipulated at that time that outdoor disconnectors could only disconnect and connect the no-load current of transformers of 560KVA and below, and indoor disconnectors could only disconnect and connect the no-load current of transformers of 320KVA and below due to the small phase-to-phase distance. The no-load current of the later S7 and S9 series transformers has been significantly reduced compared to the old transformers, but there is no new regulation to clearly limit the no-load capacity of the disconnector-operated transformer, so it can be considered as no more than 2A; as for the specific meaning of the 5A capacitive current, it is as follows: outdoor disconnectors can disconnect and connect the no-load current of overhead lines with a length of no more than 10KM. For no-load cable lines, their capacitive current is much greater than that of overhead lines of the same length, and is affected by the number of cable cores, cross-section, etc., so it is difficult to limit it with a length.
Uses
High-voltage disconnectors are divided into outdoor and indoor types. Outdoor types include single-pole switches and three-pole disconnectors, which are often used as the first disconnector to separate the power supply line from the user; indoor types are often connected in series with high-voltage circuit breakers and used in conjunction to ensure the reliability of power outages. In addition, in high-voltage complete sets of power distribution devices, disconnectors are often used as voltage transformers, lightning arresters, transformers used in distribution stations, and high-voltage control electrical appliances for metering cabinets.
Installation
Outdoor disconnectors should be installed horizontally when installed in the open air so that the supporting porcelain bottle with a porcelain skirt can indeed play a rainproof role; indoor disconnectors, when installed vertically, have the static contact on the top and can be installed at a certain angle with a sleeve. In general, the static contact is connected to the power supply and the moving contact is connected to the load. However, when the disconnector is installed in the receiving cabinet, the power supply is on the moving contact side when the cable is used. This connection method is commonly known as "reverse fire". The connection between the two sides of the disconnector and the busbar and the cable ground should be firm. When there is contact with copper and aluminum conductors, copper-aluminum transition joints should be used to prevent electrochemical corrosion.
The moving and static contacts of the disconnector should be aligned, otherwise there will be a side-hit phenomenon when closing the switch, which will make the contact surface pressure of the moving and static contacts uneven after closing, resulting in poor contact.
The operating mechanism and transmission machinery of the disconnector should be adjusted so that the opening and closing operations can be carried out normally without resistance. It is also necessary to meet the requirements of three-phase synchronization, that is, the three-phase moving contacts act simultaneously during opening and closing, and the deviation of different phases should be less than 3MM. In addition, when in the closing position, the moving contact must have a sufficient cutting depth to ensure that the contact area meets the requirements, but it is not allowed to close too much. It is required that the moving contact has a gap of 3 to 5MM from the base of the static contact, otherwise the supporting porcelain bottle of the static contact will be broken when the switch is closed too hard. When in the open position, there must be enough distance between the moving and static contacts to effectively isolate the live parts. This distance should not be less than 160MM, or the opening angle between the moving contact and the static contact should not be less than 65 degrees.
Operation and operation
The disconnector is equipped with a manual operating mechanism, generally using the CS6-1 type. When operating, the positioning pin must be pulled out first, and the opening and closing actions must be decisive and rapid. At the end, be careful not to use too much force. After the operation, it must be locked with the positioning pin, and the position of the moving contact must be visually checked to see if it meets the requirements.
When operating a single-pole disconnector with an insulating rod, the closing should first close the two side phases and then the middle phase; when opening, the order is the opposite.
It must be emphasized that whether the closing or opening operation should be carried out without load or the load is within the operating range allowed by the disconnector. For this reason, before operating the disconnector, it is necessary to check that the circuit breaker connected in series with it is indeed in the disconnected position. If the load of the disconnector is a transformer within the specified capacity range, all low-voltage loads of the transformer must be stopped first, and then the disconnector can be opened after it is unloaded; when supplying power, first check that the main switch on the low-voltage side of the transformer is in the disconnected position before closing the disconnector.
If an erroneous operation of opening or closing the disconnector with load occurs, another possible erroneous operation in the opposite direction should be avoided calmly. That is: after the load-related mistaken closing is found, it should not be opened immediately; when the load-related opening is found, if it has been opened, it should not be closed again (if it is opened a little and sparks are found, it can be closed immediately).
The disconnector in operation should be inspected. In the distribution station with people on duty, it should be inspected once per shift; in the distribution station without people on duty, it should be inspected at least once a week.
The content of daily inspection is mainly to observe the relevant ammeter, and its operating current should be within the normal range; secondly, according to the structure of the disconnector, check that its conductive part is in good contact, there is no overheating and discoloration, the insulation part should be intact, and there is no flashover discharge mark; and the transmission part should be normal (no distortion, deformation, pin shaft falling off, etc.).