shunt trip breaker

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mannyb

Senior Member
Location
Florida
Occupation
Electrician
A 2500a breaker is required per drawings to have a shunt trip breaker.? If the breaker has that feature how would that be installed. The breaker is a 2500a siemens breaker 480v 3phase.
 

mannyb

Senior Member
Location
Florida
Occupation
Electrician
The breaker is Siemens 2500a breaker WL series. I am not 100% that its a shunt trip breaker or has the ability to become a shunt trip breaker. The breaker is Siemens wll2f325 I cant find where if any is the diagram to allow trip to breaker.
 

mannyb

Senior Member
Location
Florida
Occupation
Electrician
Thanks I searched the manual it came with but didnt see anything that said shunt. I also searched the internet and didnt find this. I can always count on you guys on forum to help out. Thanks
 

Jraef

Moderator, OTD
Staff member
Location
San Francisco Bay Area, CA, USA
Occupation
Electrical Engineer
All modern “Power Breakers” with Electronic Trip Units (ETUs) such as the WL operate by a solenoid trip coil. It’s called a shunt trip in Breakers that have ANOTHER trip unit, because the solenoid coil is “shunting” around that trip mechanism. In breakers that have an ETU, that solenoid coil is the normal trip system, so the word “shunt” technically doesn’t apply, that’s why it’s not mentioned in the manual.

But it’s just like a shunt trip, you can externally energize that coil instead of waiting for the ETU to act on it. In the case of Siemens, the ETU has terminals for you to connect your external signal wires. So for example if they want the ST functionality as part of an E-Stop or EPO (Emergency Power Off) system, you would just wire your E-stop PB terminals to that external signal input in the ETU.

Now, IF the only reason they are asking for a “shunt trip” is because they want GFPE protection and they think it uses an external GFCT that needs to be wired to an ST, that’s incorrect. It is not necessary in the WL, you just buy the ETU that provides GF trip (for example an LSIG trip unit)
 

ron

Senior Member
Thanks I searched the manual it came with but didnt see anything that said shunt. I also searched the internet and didnt find this. I can always count on you guys on forum to help out. Thanks

The words shunt trip appear in that manual 49 times

Top right corner of page 17 is what you are looking for.
 
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