I am getting ready it install a 480volt Siemens BQD Breaker with a Field Installed 120v Shunt Trip for a Boiler. The Shunt Trip is going to an E-Stop Button near the exit of the building. I have run a black(hot), red(return), white and green to the E-Stop from a 15amp 120v Breaker and into my 480volt panel.
I have not installed a Shunt Trip in years and am a little confused on the wiring. I may be overthinking it. Is it like wiring a switch? Line to one terminal and load to the other and the E-Stop when pressed sends the 120volts telling the Shunt to Trip the 480volt breaker?
Thanks in advance for the advise.
Tommy
Piece of cakeTommy.
You need a reliable120vac source which in properly protected. Is that source Bering feed by the breaker that you want to open?
You need the E stop, it could be as simple as a toggle switch but more likely a conspicuous mushroom head push button switch that in conspicuous and easy to see/find located in a convenient spot. Since a breaker shunt trip consists of a solenoid that can be fried if !eft energized for any length of time there in a "cut-off switch" as part of the coil aßembled that opens instantasneou see ly when the breakers is tripped by the shunt trip on the cut off switch opens deenergizing the shunt trip coil. As such the switch (push button) that you choose to use can we either be maintained or momentary.
If you choose a maintained switch you will not be able to close the breaker as it will start to close and immediately trip again.unless you release the external switch to the open position. Keep in mind that this could be an extremely important feature in that case the emergency switch/push button often is remote. The question is do you want someone to reset and close the breaker it you want it to remain open? A maintained contact switch that if left close Weill prevent the breaker from being closed unintentionally of without authorization.
Please note that if you do choose a maintained contact and it is kept closed, yes the breaker will be prevented from being closed but if you have an unqualified person attempt to close the breaker it will trip immediately in the process of being closed. If done numerous time the breakers trip mech is often damaged. A unauthorized person closing the breaker may not be an issue but never the less should not be ignored.
You could even go so far as to add an indicator light to indicate if 120v power is available of the supply side of the circuit and/or an indicator light showing that the shunt trip is being energized. Indicator lights do make it easier to establish the status of the shunt trip circuit depending upon how critical the shunt trip feature is.
One other this. If you do bring power into the enclosure from a separate source you should either have a cut off switch of the door handle to disconnect the external power when opening the door or it is easier to attatch a yellow label to the outside of the door which states that there is an external power source present even though the breaker is open.