Technical Performance Of High Voltage Isolating Switch

High Voltage Isolator Switch has no arc extinguishing device and cannot be operated with load.
For a 10KV disconnector, under normal circumstances, its allowed operating range is:
1. Open and close voltage transformers and lightning arresters.
2. Open and close the charging current of the busbar.
3. Open and close no-load transformers with excitation current not exceeding 2A and no-load lines with capacitance current not exceeding 5A.
The old transformers in the 1950s and 1960s had large no-load ammeters, so it was stipulated at that time that outdoor disconnectors could only open and close the no-load current of transformers of 560KVA and below, and indoor disconnectors could only open and close 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 is significantly lower than that of 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: the outdoor disconnector can separate and close the no-load current of the overhead line with a length of no more than 10KM. For the no-load cable line, its capacitive current is much greater than that of the overhead line of the same length, and is affected by the number of cores and cross-section of the cable, so it is difficult to limit it with a length.