Operation of high-voltage drop-out fuses
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This is my first time reporting an issue, so I kindly ask all the experts for their help in resolving it: Today, when asking the construction team to use high-voltage drop-out fuses to cut off power, they first disconnected the middle phase; when attempting to disconnect the side phases, the fuses exploded, resulting in an inter-phase short circuit. Before the operation, all the isolating switches on the low-voltage side had already been opened, and the transformer was in an unloaded state. For some reason, I would appreciate it if the experts could provide an explanation.
Is interphase short circuit related to the transformer being unloaded?
This post was last edited by jjli618 on 2010-9-14 at 15:45. Pay attention to the wind direction when operating; when opening it, start by opening the middle phase. Determine the wind direction and operate against it.
Reply to 2# zyz8438: I’m trying to explain that the switch was turned off without loading it
Well, turning off the switch under load can cause arcing, and even a slight breeze may lead to inter-phase short circuits. Since it was a drop-out fuse that was pulled while the circuit was unloaded, it should not have been caused by arcing. First, separate the intermediate phase; when pulling the side sections, a phase-to-phase short circuit occurs (is it definitely a phase-to-phase short circuit, and not a single-phase ground short circuit?) ), I personally think it might be caused by an improper posture during operation!
When taking the exam for a certificate of safe electrical work, some people are able to perform the necessary operations; those with poor basic skills end up performing incorrect operations, which can cause the equipment to short-circuit. If that doesn’t happen, one can only imagine arcs occurring when the switch is turned off, and these arcs being caused by wind to lead to inter-phase short circuits