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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{| class="twocolortable" style="text-align: left; font-size: 12px;width:40%"
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|-
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|Gold     
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|0.03 N
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|-
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|Silver   
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|0.1 N
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|-
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|Tungsten 
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|0.5 N
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|-
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|}
  
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<table class="twocolortable" style="text-align: left; font-size: 12px;width:40%">
 
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<tr>
 
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<td>Gold</td>     
 
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<td>0.03 N </td>
 
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</tr><tr>
 
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<td>Silver </td>
 
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<td>0.1 N</td>
 
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</tr><tr>
 
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<td>Tungsten  </td>
 
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<td>0.5 N</td>
 
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</tr>
 
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</table>
 
  
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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|left|General Rules for Dimensioning of Contact Rivets]]
 
{| class="twocolortable" style="text-align: left; font-size: 12px;width:100%"
 
{| class="twocolortable" style="text-align: left; font-size: 12px;width:100%"
 
|-
 
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*'''Head diameter for electrical loads'''
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{| class="twocolortable" style="text-align: left; font-size: 12px;width:40%"
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|-
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|For AC currents:   
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|approx. 1 – 1.5 A/mm²
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|-
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|For 1 A 
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|min. 2 mm head diameter
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|-
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|10 A 
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|approx. 3 – 3.5 mm head diameter
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|-
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|20 A 
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|approx. 5 mm head diameter
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|-
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|For DC currents:
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|approx. 0.5 – 0.8 A/mm²
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|}
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*'''Head radius R for electrical loads'''
  
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{| class="twocolortable" style="text-align: left; font-size: 12px;width:40%"
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|-
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|for I < 1 A   
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|R &#8776; 1,5 mm
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|-
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|I = 6 A   
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|R &#8776; 5 mm
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|-
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|I = 10 A   
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|R &#8776; 10 mm
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|-
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|I = 20 A   
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|R &#8776; 15 mm
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|}
  
  
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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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{| class="twocolortable" style="text-align: left; font-size: 12px;width:40%"
 
|-
 
|-
 
!Contact force[N]     
 
!Contact force[N]     
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|3.2 x 10<sup>-10</sup>
 
|3.2 x 10<sup>-10</sup>
 
|}
 
|}
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<div class="multiple-images">
 
<div class="multiple-images">
 
<figure id="fig:Failure probability of a contact as a function of the voitage">
 
<figure id="fig:Failure probability of a contact as a function of the voitage">
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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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[[File:Failure probability of a contact as a function of the voitage.jpg|left|Failure probability of a contact as a function of the voltage (according to Kirchdorfer); Ag/Ni10; 10 mA]]
 
</figure>
 
</figure>
  
 
<figure id="fig:Failure probability of a contact as a function of the current">
 
<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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[[File:Failure probability of a contact as a function of the current.jpg|left|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]]
 
</figure>
 
</figure>
 
</div>
 
</div>
 
<div class="clear"></div>
 
<div class="clear"></div>
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<xr id="fig:Failure probability of a contact as a function of the voitage"/> Fig. 6.18: Failure probability of a contact as a function of the voltage (according to Kirchdorfer); Ag/Ni10; 10 mA
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<xr id="fig:Failure probability of a contact as a function of the current"/> 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==
 
[[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 16:31, 7 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
Dimensioning Solid Rivets (1) Composite Rivets (2)
a : d 1.5 : 1 bis 2.5 : 1 2 : 1 bis 2.5 : 1
a : b 2.5 : 1 bis 10 : 1 3 : 1 bis 5 : 1
c : b ≥ 1 : 1 ≥ 1 : 1
b : s ≥ 2 : 1
smin ≈ 0.3 mm


  • 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)


Contact force[N] Single contact
Ag AuNi 5, Pt Ag AuNi 5, Pt
0.04 1 x 10-4 2 x 10-8
0.1 2 x 10-3 4 x 10-5 8 x 10-5 8 x 10-9
0.2 1 x 10-4 8 x 10-6 4 x 10-6 4 x 10-8
0.3 5.5 x 10-6 1.5 x 10-6 1.8 x 10-7 3.2 x 10-10
Failure probability of a contact as a function of the voltage (according to Kirchdorfer); Ag/Ni10; 10 mA
Failure probability of a contact as a function of the current (according to Kirchdorfer); Ag/Ni10; Fk = 0.45 N; U = 24 V

Figure 1 Fig. 6.18: Failure probability of a contact as a function of the voltage (according to Kirchdorfer); Ag/Ni10; 10 mA

Figure 2 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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