Why not to close breaker 2

[budhiman]

In the attachment, it says "Control power to the Shunt Trip with Lockout must be removed for a minimum of 0.25 seconds before the breaker can be closed". Why wait for 0.25 seconds what is logic behind it.

 

[FreddyNurk]

Can only assume that it's a conservative thing to ensure that the shunt trip actuator is fully retracted (disengaged?) prior to attempting to close the breaker. The alternative is that the breaker keeps tripping on close as the shunt trip is still engaged.

EDMS Australia

 

[RRaghunath]

Agree with FreddyNurk, the 250ms is conservatively taken to ensure that the Trip/Lockout solenoid drops-off and the plunger retracts completely.

 

[TugboatEng]

What is the difference between "shunt trip" and "shunt trip with lockout"? That difference is the reason for the delay.