Abstract: Lightning-induced conductor breakage accidents in distribution lines severely threaten power supply quality and grid safety. As arc discharge is the direct cause of such failures, in-depth investigation of its erosion characteristics is crucial for revealing the mechanism of lightning-induced conductor damage. This study investigates the erosion effects on conductors caused by two typical lightning-induced arcs in 10 kV systems: single-phase grounding fault arcs (low current) and three-phase short-circuit fault arcs (high current). A laboratory platform simulating 10 kV single-phase grounding faults is established to conduct low-current arc erosion experiments. Additionally, a simulation model for high-current arc erosion under phase-to-phase short-circuit conditions is developed to analyze the conductor degradation effects. Results indicate that low-current arcs produced by lightning-initiated single-phase grounding faults cause conductor strand breakage sustained action for 40 minutes, a duration shorter than the maximize permissible operating time threshold for such faults in distribution networks. High-current arcs from phase-to-phase short circuits exhibit intensified conductor erosion with increasing arc length and current magnitude. A high-current arc with a 5 kA peak can completely melt the conductor within 91 ms, which is shorter than the typical instantaneous trip protection operation time of distribution circuit breakers.