How long must the signal be applied to the shunt trip on a Masterpact NW breaker?
How long must the signal be applied to the shunt trip and shunt close on a Masterpact NW breaker to ensure proper operation?
Resolution: The breaker requires a shunt trip energization time of 200 ms to ensure that the breaker trip mechanism has completed its cycle and has returned to its starting point. A shorter signal has the risk of causing the mechanism to hang up and not close with the next close signal. It would close with a second signal however.
To prevent operating problems, do not pass the signal through an aux. contact (which will open in less than 50 ms). If a PLC is used, ensure the signal duration is 200 ms or more.