Inspection and Monitoring of Low-Voltage 0.4 Kv Cable Lines Using an Electric Arc Detection Device

Abstract

This article examines the pressing issue of ensuring fire safety in low-voltage cable lines (up to 1000 V) related to electric arcs. It is shown that traditional protection measures-circuit breakers and residual-current devices (RCDs)-are not always effective, especially during sequential arc faults, when the arc current is equal to the load current and does not trigger the overcurrent protection. The main causes of arc discharges are analyzed: mechanical damage to insulation, loose contact connections, cable aging, and external influences. A portable arc detection unit is proposed as a solution, allowing for rapid diagnostics directly on-site during commissioning. The device consists of a dielectric housing with a removable transparent cover, housing an arc fault detection device (AFDD) and a voltage and current indicator (ampere-voltmeter). The design allows for real-time visual monitoring of network parameters without opening the housing. A diagnostic method is described that involves connecting a diagnostic system to a tested line with an adjustable load and analyzing the condition of each cable section. Upon detecting an arc, the module disconnects the protected line, signaling the need for repairs. Experiments have confirmed that a complete test cycle for one line takes less than ten minutes. The proposed method is safe, versatile, accurate, and cost-effective. Implementation of the developed device will significantly reduce the risk of fires caused by arc faults and improve the reliability of power supply to various facilities. The device is protected by a utility model patent.