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

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(6.4.6 General Rules for Dimensioning of Contacts)
(6.4.6 General Rules for Dimensioning of Contacts)
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*'''Recommended Minimum Contact Forces at Slightly Sliding Contact Make:'''
 
*'''Recommended Minimum Contact Forces at Slightly Sliding Contact Make:'''
  
{| class="twocolortable" style="text-align: left; font-size: 12px;width:30%"
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{| class="twocolortable" style="text-align: left; font-size: 12px;width:40%"
 
|-
 
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|Gold       
 
|Gold       
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*'''Contact Force Recommendations:'''
 
*'''Contact Force Recommendations:'''
  
Signal relays >3 cN
+
{| class="twocolortable" style="text-align: left; font-size: 12px;width:40%"
AC power relays > 20 cN
+
|-
Automotive relays > 20 cN
+
|Signal relays    
Motor switches (Contactors) 0.05 - 0.08 N/A
+
|≥3 cN
(Silver – Metal oxide contacts)
+
|-
Power switches 0.1 - 0.2 N/A
+
|AC power relays  
Connectors > 30 cN/contact element
+
|≥ 20 cN
(Gold coating)
+
|-
Connectors > 50 cN/contact element
+
|Automotive relays
(Silver coating)
+
|≥ 20 cN
Connectors > 1 N/contact element
+
|-
(Tin coating)
+
|Motor switches (Contactors)<br />(Silver – Metal oxide contacts)
 +
|0.05 - 0.08 N/A
 +
|-
 +
|Power switches
 +
|0.1 - 0.2 N/A
 +
|-
 +
|Connectors<br />(Gold coating)
 +
|&ge; 30 cN/contact element
 +
|-
 +
|Connectors<br />(Silver coating)
 +
|&ge; 50 cN/contact element
 +
|-
 +
|Connectors<br />(Tin coating)
 +
|&ge; 1 N/contact element
 +
|}
 +
 
  
 
*'''General Rules for Dimensioning of Contact Rivets'''
 
*'''General Rules for Dimensioning of Contact Rivets'''

Revision as of 10:19, 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

bild

  • 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