Intrinsically Safe Supply System by Means of Multi-Pair Telecommunication Cables

Abstract

Abstract The conditions of intrinsically safe power transmission to telecommunication devices and safety parameter control systems located in potentially explosive zones via a line track using central source of remote supply featuring linear and non-linear output characteristics was discussed in the present work. It was proved that, when applying such remote power supply featuring linear output characteristics, the application of line track with larger diameter of working wires would ensure neither a decrease of power losses on isolated resistance of line track nor an increase of remotely transmitted intrinsically safe power in a proportional way. As a more effective method appeared here the arrangement of remote intrinsically safe supply system using separate power transmission channels, i.e. several line tracks with a smaller diameter of working wires. The use of a protective system featuring non-linear output characteristics at the input of remote power transmission system would allow elimination of the influence exerted by the remote power supply upon formation of explosive mixture ignition core at the emergency commutation point, where a protective system ensuring separation of power generated by the power supply by shorting its output terminals would be more advantageous from the discharging energy minimization viewpoint.