Closing Resistor
2
Operating principle of the closing resistor: Step 1: CB fully open Step 2: Closing (beginning of insertion) Step 3: Closing (end of insertion) Step 4: CB fully closed (in service) R Resistor Contact Arcing Contact Main Contact R Resistor Contact Open – Resistor in Circuit Arcing Contact Closed Main Contact R Arcing Contact Closed Main Contact Resistor Contact Closed (5-8 ms after arcing contact) - Resistor bypassed R Arcing Contact Closed Main Contact Closed Resistor Contact Closed – Resistor bypassed
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Transcript of Closing Resistor
Operating principle of the closing resistor:
Step 1: CB fully open
Step 2: Closing (beginning of insertion)
Step 3: Closing (end of insertion)
Step 4: CB fully closed (in service)
R
Resistor Contact
Arcing Contact
Main Contact
R
Resistor Contact Open – Resistor in Circuit
Arcing Contact Closed
Main Contact
R
Arcing Contact Closed
Main Contact
Resistor Contact Closed (5-8 ms after arcing contact) - Resistor bypassed
R
Arcing Contact Closed
Main Contact Closed
Resistor Contact Closed – Resistor bypassed
Step 5: Opening (Main contact)
Step 6: Opening (Arcing contact)
Step 7: CB fully open (Resistor contact open)
Advantages:1. Resistor switching controlled by main contact system – High reliability2. Resistor always remains bypassed after closing – No possibility of short circuit current
flowing through resistor – No explosions
R
Arcing Contact Closed
Main Contact
Resistor Contact Closed – Resistor bypassed
R
Arcing Contact
Main Contact
Resistor Contact Closed – Resistor bypassed
R
Resistor Contact – Opens >100 ms after arcing contact
Arcing Contact
Main Contact
