How are outdoor high-voltage disconnect switches operated and run?

There are many precautions to take when operating outdoor high-voltage disconnect switches. So what are the main precautions?

Outdoor high-voltage disconnect switches are equipped with manual operating mechanisms, generally the CS6-1 type. When operating, first pull out the positioning pin. The opening and closing actions should be decisive and rapid. At the end, be careful not to use excessive force. After operation, be sure to lock the switch with the positioning pin and visually inspect whether the position of the moving contact meets the requirements.

When operating a single-pole disconnecting switch with an insulating rod, closing should begin with closing the two outer phases, followed by the middle phase; opening is the reverse sequence. It must be emphasized that both closing and opening operations should only be performed when there is no load or the load is within the disconnecting switch's permissible operating range. Therefore, before operating the disconnecting switch, it is essential to check that the circuit breaker connected in series with it is indeed in the open position. If the load connected to the disconnecting switch is a transformer within its specified capacity range, all low-voltage loads on the transformer must be shut off first, allowing it to operate without load, before opening the disconnecting switch; when energizing, first check that the main switch on the low-voltage side of the transformer is in the open position before closing the disconnecting switch.

If a misoperation of opening or closing a disconnecting switch under load occurs, one should calmly avoid another misoperation in the opposite direction. That is: if a misoperation of closing under load is discovered, it should not be opened immediately; if a misoperation of opening under load is discovered, and it has already been opened, it should not be closed again (if it has been opened slightly and sparks are observed, it can be closed immediately).

Outdoor high-voltage disconnect switches in operation should be inspected. In manned substations, this should be done once per shift; in unmanned substations, it should be done at least once per week.

The main tasks of routine inspections are to observe the relevant ammeters and ensure that their operating current is within the normal range; secondly, based on the structure of the disconnecting switch, check that its conductive parts have good contact, no overheating or discoloration, that the insulation parts are intact, and that there are no signs of flashover discharge; and thirdly, check that the transmission parts are free from abnormalities (no twisting or deformation, pins falling off, etc.).