The current at which a magnetic-type overload relay tends to trip may be decreased by raising the plunger further into the magnetic circuit of the relay. What effect does this action have?
ā¢ Relationship between magnetic flux and distance/air gap in a magnetic circuit ā¢ How moving the plunger deeper into the magnetic field changes the force on it for the same current ā¢ What happens to the trip current if the relay is easier or harder to pull in
ā¢ If the plunger is moved further into the magnetic circuit, does the air gap become larger or smaller, and how does that affect magnetic pull? ā¢ With stronger magnetic pull at a given current, would the relay trip at a higher or lower current? ā¢ Which answer choice correctly pairs the change in magnetic pull with the needed trip current direction (more or less)?
ā¢ Decide clearly: does raising the plunger increase or reduce magnetic pull for the same current? ā¢ Then decide: with that change in magnetic pull, does the relay need more or less current to reach the trip point? ā¢ Verify that your final choice has both parts (magnetic pull and trip current) logically consistent with each other.
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