What is the purpose of an "anti-pumping relay"?
This Quora entry seems to explain this in detail. Here: https://www.quora.com/What-is-the-use-of-an-antipumping-relay


  a) How does a circuit breaker 'hunt'?


When the operator pushes the 'close' button, the breaker can cycle through multiple trip-and-resets while the operator is still pushing the button.


  b) How do repetitive circuit-breaker closures occur?


If there is a repeated fault trip (see above.)


  c) What does an anti-pumping relay do?


Conditions the button press to make one and only one attempt to close the breaker. If a fault occurs, the fault trip breaker will not be reset until the operator releases the button.  This interrupts the trip-and-reset loop.