医用电气设备可触及金属部件保护接地要求分析

摘要

Objective To study the protective earth requirement for touched metal parts of medical electrical equipment to improve the manufacturer's understanding on national standards.Methods The isolation methods for the touched metal parts in national standards were studied,and the principle of protective earth combined with insulation separating was analyzed.The characteristics of the second isolation method was discussed,and the respiratory system structure and electroshock protection of the anaesthetic machine were taken as examples.Results The touched metal parts with no measures for grounding,double isolation or reinforced insulation was determined by structure detection to meet the requirements of national standards in case basic insulation ceased to be effective and the parts were uncharged.Conclusion The necessities to girt the touched metal parts with measures for grounding,double isolation or reinforced insulation should depend on the understanding on national standards and electrical construction of the equipment under test by structure detection.%目的:探讨医用电气设备可触及金属部件的保护接地要求,帮助制造商理解国家标准对保护接地的要求,以便合理设计产品.方法:通过研究国家标准对可触及金属部件的隔离方法,分析保护接地配合基本绝缘隔离方法的防护原理,讨论隔离方法(2)——用保护接地的金属部件隔离的特征条件,并举例对麻醉机的呼吸系统结构及电击防护方式进行分析.结果:对于不满足保护接地和双重绝缘或加强绝缘的可触及金属部件,如果基本绝缘失效时,可触及金属部件不带电,则通过结构检查,可判定可触及金属部件满足国家标准要求.结论:只有对标准条款进行深入全面的理解,通过结构检查对被测设备的电气结构有清晰的认识,才能对可触及金属部件是否需要保护接地或双重绝缘或加强绝缘做出准确公正的判断.