Direct and indirect contact: Difference between revisions

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A direct contact refers to a person coming into contact with a conductor which is live in normal circumstances (see '''Fig. F2'''). IEC 61140 standard has renamed “protection against direct contact” with the term “basic protection”. The former name is at least kept for information.<br>
A direct contact refers to a person coming into contact with a conductor which is live in normal circumstances (see {{FigRef|F2}}). IEC 61140 standard has renamed “protection against direct contact” with the term “basic protection”. The former name is at least kept for information.
 
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[[File:FigF02.jpg|none]]
[[File:FigF02.jpg|none]]
'''''Fig. F2: '''Direct contact''  
'''''Fig. F2: '''Direct contact''
 
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===== Indirect contact  =====
===== Indirect contact  =====
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An indirect contact refers to a person coming into contact with an exposed-conductive-part which is not normally alive, but has become alive accidentally (due to insulation failure or some other cause).<br>The fault current raise the exposed-conductive-part to a voltage liable to be hazardous which could be at the origin of a touch current through a person coming into contact with this exposed-conductive-part (see '''Fig. F3''').IEC 61140 standard has renamed “protection against indirect contact” with the term “fault protection”. The former name is at least kept for information.  
An indirect contact refers to a person coming into contact with an exposed-conductive-part which is not normally alive, but has become alive accidentally (due to insulation failure or some other cause).<br>The fault current raise the exposed-conductive-part to a voltage liable to be hazardous which could be at the origin of a touch current through a person coming into contact with this exposed-conductive-part (see {{FigRef|F3}}).IEC 61140 standard has renamed “protection against indirect contact” with the term “fault protection”. The former name is at least kept for information.  





Revision as of 15:14, 24 November 2016


Direct contact

Two measures of protection against direct contact hazards are often required, since, in practice, the first measure may not be infallible

A direct contact refers to a person coming into contact with a conductor which is live in normal circumstances (see Fig. F2). IEC 61140 standard has renamed “protection against direct contact” with the term “basic protection”. The former name is at least kept for information.

FigF02.jpg

Fig. F2: Direct contact

Indirect contact

Standards and regulations distinguish two kinds of dangerous contact,

  • Direct contact
  • Indirect contact

 and corresponding protective measures


An indirect contact refers to a person coming into contact with an exposed-conductive-part which is not normally alive, but has become alive accidentally (due to insulation failure or some other cause).
The fault current raise the exposed-conductive-part to a voltage liable to be hazardous which could be at the origin of a touch current through a person coming into contact with this exposed-conductive-part (see Fig. F3).IEC 61140 standard has renamed “protection against indirect contact” with the term “fault protection”. The former name is at least kept for information.


FigF03.jpg

Fig F3: Indirect contact

ru:Прямое и косвенное прикосновения zh:直接接触和间接接触

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