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shunt breaker

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CCC79cedric

Member
Location
joliet,illinois
Occupation
electrician
hooking up ansul system and style of shunt trip breaker is a sieman bq style 20 amp 2 pole bolt on breaker with a white coil wire.i was wondering where do I hook up the white wire.the breaker is tripping but the make up air shuts off when the micro switch close.
 
LarryFine

LarryFine

Master Electrician Electric Contractor Richmond VA
Location
Henrico County, VA
Occupation
Electrical Contractor
The breaker should have two wires; one connected to the panel's neutral bar, the other energized to trip. Most shunt-trip breakers cannot haver the coil constantly energized, so should be powered by something that loses power upon system trip.

If there's only one, the coil's other wire must be internally powered, meaning you'd have to have the white wire connect to neutral to trip, but I've never seen one like that.

And the make-up air should shut down upon system trip.
 
C

CCC79cedric

Member
Location
joliet,illinois
Occupation
electrician
The white wire(coil) goes to the neutral of the device or bar.so we have a 2 pole shunt trip breaker with a white coil.there are no wire sticking out.So I land the shunt trip hot on 1 pole of the breaker and land the neutral on the other pole or the neutral bar with the coil
 
LarryFine

LarryFine

Master Electrician Electric Contractor Richmond VA
Location
Henrico County, VA
Occupation
Electrical Contractor
That sounds like it will trip the moment you turn on the breaker.

So, are there two white wires? You said only one before.
 
G

gar

Senior Member
Location
Ann Arbor, Michigan
Occupation
EE
200221-1143 EST

CCC79cedric:

You and many other electricians need to study electrical circuit theory, and how the various components work that you connerct together.

What is a shunt trip breaker, and how does it work? I have never seen or worked with one, and therefore I don't know. What does the word shunt mean? See https://www.dictionary.com/browse/shunt . In a somewhat more general statement --- a shunt is something in parallel.

An ordinary single pole circuit breaker has one actuator mechanism to trip the breaker. In a Sq-D QO breaker this is a single U shaped bimetal device that is both a thermal and magnetic actuator.

In electrical circuits using the concept of positive logic parallel switches perform the logical function of "inclusive OR". This means that if any one or more inputs are 1, then the output is 1. Whereas a two input "exclusive OR" has a 1 output when only one input is a 1. This is the basis of a binary adder.

Back to the shunt trip breaker. This is a breaker where more than one mechanical thing can trip the breaker. These would be at least the breaker lever, one or more current sensors, and one or more remotely triggered actuators.

Looking on the internet I have seen a QO with a side package with two terminals for the remote turn off control. These would be wired to a voltage source thru a series switch.

Look at the data sheet for your breaker and see if it tells you how the breaker works. Otherwise make measurements on your breaker, and figure out how it works.

.
 
kwired

kwired

Electron manager
Location
NE Nebraska
Occupation
EC
gar said:
200221-1143 EST

CCC79cedric:

You and many other electricians need to study electrical circuit theory, and how the various components work that you connerct together.

What is a shunt trip breaker, and how does it work? I have never seen or worked with one, and therefore I don't know. What does the word shunt mean? See https://www.dictionary.com/browse/shunt . In a somewhat more general statement --- a shunt is something in parallel.

An ordinary single pole circuit breaker has one actuator mechanism to trip the breaker. In a Sq-D QO breaker this is a single U shaped bimetal device that is both a thermal and magnetic actuator.

In electrical circuits using the concept of positive logic parallel switches perform the logical function of "inclusive OR". This means that if any one or more inputs are 1, then the output is 1. Whereas a two input "exclusive OR" has a 1 output when only one input is a 1. This is the basis of a binary adder.

Back to the shunt trip breaker. This is a breaker where more than one mechanical thing can trip the breaker. These would be at least the breaker lever, one or more current sensors, and one or more remotely triggered actuators.

Looking on the internet I have seen a QO with a side package with two terminals for the remote turn off control. These would be wired to a voltage source thru a series switch.

Look at the data sheet for your breaker and see if it tells you how the breaker works. Otherwise make measurements on your breaker, and figure out how it works.

.
Click to expand...

What is in parallel is an additional trip means that is triggered by powering the "shunt coil"

some of them are designed so that they open circuit to the shunt coil when the breaker opens and that keeps the shunt coil from burning out when power to coil still remains. Most are not rated for continuous power to the shunt coil. Others you may have to arrange so that the control power is derived from the circuit the breaker supplies so that it will not leave the coil energized after tripping.
 
B

bwat

EE
Location
NC
Occupation
EE
LarryFine said:
Most shunt-trip breakers cannot haver the coil constantly energized, so should be powered by something that loses power upon system trip.
Click to expand...

I did not know this several years ago and I burnt out a few shunt trip coils out of my ignorance... important info right there.
 
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