Difference between revisions of "General Rules for Dimensioning of Contacts"

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===<!--6.4.6-->General Rules for Dimensioning of Contacts===
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===6.4.6 General Rules for Dimensioning of Contacts===
  
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'''Recommended Minimum Contact Forces at Slightly Sliding Contact Make:'''
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*'''Recommended Minimum Contact Forces at Slightly Sliding Contact Make:'''
  
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<table class="twocolortable" style="text-align: left; font-size: 12px;width:40%">
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{| class="twocolortable" style="text-align: left; font-size: 12px;width:40%"
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<tr>
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|-
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<td>Gold</td>      
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|Gold       
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<td>0.03 N </td>
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|0.03 N
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</tr><tr>
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|-
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<td>Silver </td>
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|Silver  
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<td>0.1 N</td>
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|0.1 N
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</tr><tr>
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|-
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<td>Tungsten  </td>
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|Tungsten   
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<td>0.5 N</td>
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|0.5 N
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</tr>
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|-
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</table>
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|}
  
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'''Contact Force Recommendations:'''
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*'''Contact Force Recommendations:'''
  
 
{| class="twocolortable" style="text-align: left; font-size: 12px;width:40%"
 
{| class="twocolortable" style="text-align: left; font-size: 12px;width:40%"
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'''General Rules for Dimensioning of Contact Rivets'''
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*'''General Rules for Dimensioning of Contact Rivets'''
  
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[[File:General Rules for Dimensioning of Contact Rivets.jpg|left|thumb|Figure 1: General Rules for Dimensioning of Contact Rivets]]
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[[File:General Rules for Dimensioning of Contact Rivets.jpg|right|thumb|General Rules for Dimensioning of Contact Rivets]]
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{| class="twocolortable" style="text-align: left; font-size: 12px;width:100%"
 
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|-
 
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!Dimensioning
 
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!Solid Rivets (1)
 
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!Composite Rivets (2)
 
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|-
 
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|a : d     
 
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|1.5 : 1 bis 2.5 : 1
 
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|2 : 1 bis 2.5 : 1
 
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|-
 
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|a : b     
 
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|2.5 : 1 bis 10 : 1
 
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|3 : 1 bis 5 : 1
 
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|-
 
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|c : b     
 
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|&ge; 1 : 1
 
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|&ge; 1 : 1
 
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|-
 
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|b : s     
 
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|
 
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|&ge; 2 : 1
 
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|-
 
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|s<sub>min</sub>   
 
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|
 
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|&#8776; 0.3 mm
 
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|}
 
  
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*'''Head diameter for electrical loads'''
  
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For AC currents: approx. 1 – 1.5 A/mm²
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For 1 A min. 2 mm head diameter
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10 A approx. 3 – 3.5 mm head diameter
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20 A approx. 5 mm head diameter
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For DC currents: approx. 0.5 – 0.8 A/mm²
  
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*'''Head radius R for electrical loads'''
  
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for I < 1 A R 1,5 mm
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I = 6 A R 5 mm
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I = 10 A R 10 mm
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I = 20 A R 15 mm
  
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'''Failure Probability of Single and Double (Bifurcated) Contacts''' (according to Thielecke)
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*'''Failure Probability of Single and Double (Bifurcated) Contacts''' (according to Thielecke)
  
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{| class="twocolortable" style="text-align: left; font-size: 12px;width:100%"
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Fig. 6.18: Failure probability of a contact as a
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|-
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function of the voltage (according to Kirchdorfer);
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!Contact force[N]   
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Ag/Ni10; 10 mA
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!colspan="4" style="text-align:center"|'''Single contact'''
 
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|-
 
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!   
 
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!Ag
 
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!AuNi 5, Pt
 
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!Ag
 
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!AuNi 5, Pt
 
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|-
 
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|0.04 
 
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|
 
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|1 x 10<sup>-4</sup>
 
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|
 
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|2 x 10<sup>-8</sup>
 
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|-
 
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|0.1 
 
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|2 x 10<sup>-3</sup>
 
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|4 x 10<sup>-5</sup>
 
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|8 x 10<sup>-5</sup>
 
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|8 x 10<sup>-9</sup>
 
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|-
 
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|0.2
 
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|1 x 10<sup>-4</sup>
 
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|8 x 10<sup>-6</sup>
 
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|4 x 10<sup>-6</sup>
 
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|4 x 10<sup>-8</sup>
 
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|-
 
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|0.3
 
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|5.5 x 10<sup>-6</sup>
 
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|1.5 x 10<sup>-6</sup>
 
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|1.8 x 10<sup>-7</sup>
 
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|3.2 x 10<sup>-10</sup>
 
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|}
 
  
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Fig. 6.19: Failure probability of a contact as a
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<div class="multiple-images">
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function of the current (according to
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<figure id="fig:Failure probability of a contact as a function of the voitage">
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Kirchdorfer); Ag/Ni10; F = 0.45 N; U = 24 V
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[[File:Failure probability of a contact as a function of the voitage.jpg|left|thumb|Figure 2: Failure probability of a contact as a function of the voltage (according to Kirchdorfer); Ag/Ni10; 10 mA]]
 
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</figure>
 
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<figure id="fig:Failure probability of a contact as a function of the current">
 
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[[File:Failure probability of a contact as a function of the current.jpg|left|thumb|Figure 3: Failure probability of a contact as a function of the current (according to Kirchdorfer); Ag/Ni10; F<sub>k</sub> = 0.45 N; U = 24 V]]
 
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</figure>
 
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</div>
 
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<div class="clear"></div>
 
  
 
==References==
 
==References==
 
[[Application Tables and Guideline Data for Use of Electrical Contact Design#References|References]]
 
[[Application Tables and Guideline Data for Use of Electrical Contact Design#References|References]]
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[[de:Faustregeln_für_die_Kontaktdimensionierung]]
 

Revision as of 10:26, 2 April 2014

6.4.6 General Rules for Dimensioning of Contacts

  • Recommended Minimum Contact Forces at Slightly Sliding Contact Make:
Gold 0.03 N
Silver 0.1 N
Tungsten 0.5 N
  • Contact Force Recommendations:
Signal relays ≥ 3 cN
AC power relays ≥ 20 cN
Automotive relays ≥ 20 cN
Motor switches (Contactors)
(Silver – Metal oxide contacts) 		0.05 - 0.08 N/A
Power switches 0.1 - 0.2 N/A
Connectors
(Gold coating) 		≥ 30 cN/contact element
Connectors
(Silver coating) 		≥ 50 cN/contact element
Connectors
(Tin coating) 		≥ 1 N/contact element


  • General Rules for Dimensioning of Contact Rivets
General Rules for Dimensioning of Contact Rivets
  • Head diameter for electrical loads

For AC currents: approx. 1 – 1.5 A/mm² For 1 A min. 2 mm head diameter 10 A approx. 3 – 3.5 mm head diameter 20 A approx. 5 mm head diameter For DC currents: approx. 0.5 – 0.8 A/mm²

  • Head radius R for electrical loads

for I < 1 A R 1,5 mm I = 6 A R 5 mm I = 10 A R 10 mm I = 20 A R 15 mm

  • Failure Probability of Single and Double (Bifurcated) Contacts (according to Thielecke)

Fig. 6.18: Failure probability of a contact as a function of the voltage (according to Kirchdorfer); Ag/Ni10; 10 mA

Fig. 6.19: Failure probability of a contact as a function of the current (according to Kirchdorfer); Ag/Ni10; F = 0.45 N; U = 24 V

References

References

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