Sustainable Mining and Metallurgy

Based on the structure and anti-shock principle of isolation transformer, the differences between isolation transformer and ordinary transformer were compared. The isolation transformer had excellent isolation and anti-interference ability because the primary winding and secondary winding were arranged in different centers, or the windings were concentric, but the electrostatic shielding layers were set between the windings, and there were double insulation or enhanced insulation between the windings. This paper introduced the principle and key points of practical application of isolation transformer as electrical isolation, converting TN or TT system to IT system in the occasion of high requirements of electric shock protection, power supply for safe special low voltage system, and suppression of high frequency interference. In addition，three practical cases were cited to analyze the misuse of isolating transformer, and emphasize that the setting requirements of isolating transformer should be paid attention to when adopting isolating transformer, so as to avoid its functional failure，and it was not necessary to blindly select isolating transformer, so as to avoid increasing investment and causing waste of resources.