The Direct Threat Posed By The Lack Of Arc-extinguishing Capability Of High-voltage Disconnect Switches

The safe operation of a power system depends on the normal operation of various electrical equipment. As an important isolation device, the High Voltage Disconnect Switch has a relatively simple structure, but its potential risk factors are often overlooked. The lack of an arc-extinguishing device is an inherent characteristic of this type of equipment, which can lead to severe electric arcing under certain operating conditions.

The absence of an arc-extinguishing device in high-voltage disconnect switches limits their operation to handling no-load circuits. If an operator mistakenly performs a disconnection operation under load, a strong electric arc will occur between the contacts, with instantaneous temperatures reaching thousands of degrees Celsius. This can immediately damage the contact surface and may cause phase-to-phase arcing short circuits. This situation can easily trigger malfunctions in relay protection devices, causing substation circuit breakers to trip and potentially leading to widespread power outages.