医用超声诊断仪系统接地的改进研究

目的:研究超声诊断仪系统接地的现状和改进的必要性。分析TT型、TN-C型和TN-S型系统接地的优缺点及其差别。方法:对TT型系统接地,用1根保护零线(PE)将工作接地线与保护接地线连接起来;对TN-C型系统接地,需另加1根保护地线,并将原接到N线上的PE线拆除,换上1根连接供电变压器中性点的PE线。结果:提出了超声诊断仪TN-S型系统接地的判断方法及TT型和TN-C型系统接地的改进措施。结论:可将TT型和TN-C型系统接地改进为TN-S型系统接地。

Improvement of system grounding for medical ultrasound diagnose equipment

Objective：To point out the present situation and improving necessity of system grounding in medical ultrasound diagnose equipment.Methods：We have analyzed the advantages,disadvantages and the differences between TT type,TN-C type system grounding and TN-S type system grounding in medical ultrasound diagnose equipment.We put forward the assessment methods of TN-S type in medical ultrasound diagnose equipment and improving measures of TT type,TN-C type system grounding.Results：Improving TT type of system grounding to TN-S type of system grounding needs a PE line as thick as the phase line.Improving TN-C type of system grounding to TN-S type of system grounding needs two grounding lines as thick as the phase line.Using a PE line connects working grounding line with protecting grounding line for TT type of system grounding and adding protecting grounding line and disconnect former PE line from N line could change a new PE line connect the center point of power supply transformer for TN-C type system grounding.Conclusion：We can improve the TT type and TN-C type system to TN-S type system grounding.