charging breaker before closing

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templdl

Senior Member
Location
Wisconsin
It's the charged spring that drives the contacts closed.
With the spring in the discharged position the breaker is open and can not be closed. As such charge the spring and then you can push the close button to close the breaker and then it can be opened. The spring must be charged again to close the breaker.
No if you charge the spring and close the breaker. You can charge the spring with the breaker in its closed position. In doing so you are able to open the breaker, close it again and then open it again.
By charging the breaker while it?s in the open position you get a close and open.
Should you charge the sping again after closing it you get an open-close-open.
 
weressl

weressl

Esteemed Member
Location
Texas by the Gulf, geat crab, great shrimp
templdl said:
It's the charged spring that drives the contacts closed.
With the spring in the discharged position the breaker is open and can not be closed. As such charge the spring and then you can push the close button to close the breaker and then it can be opened. The spring must be charged again to close the breaker.
No if you charge the spring and close the breaker. You can charge the spring with the breaker in its closed position. In doing so you are able to open the breaker, close it again and then open it again.
By charging the breaker while it?s in the open position you get a close and open.
Should you charge the sping again after closing it you get an open-close-open.
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Simply, the charging has a single objective; to always have sufficient stored energy to OPEN the breaker.
 
SG-1

SG-1

Senior Member
Location
Ware Shoals, South Carolina
You "charge" the closing spring(s) manually with some type of handle. Some breakers have electric motors that automatically charge the closing spring(s) The closing spring(s) "discharges" it's mechanical energy to close the breaker contacts & charge the opening spring(s).
 
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broadgage

Senior Member
Location
London, England
The spring inside a large circuit breaker must allways be able to OPEN the breaker, even if someone has omitted to charge the spring.

The mechanism is therefore designed in such a way that before the breaker can be closed, it is proved that the spring contains sufficient energy not only to close the breaker but also to subsequently open it.
If the spring does not contain enough energy to close and SUBSEQUENTLY OPEN the circuit breaker, then closing is mechanicly locked out until the spring has been charged.
 
zog

zog

Senior Member
Location
Charlotte, NC
pauld said:
Please explain the charging prior to engaging the breaker and the discharge of breaker
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Is there a specific breaker type you are asking about? Generic descriptions have been covered here already but there are many different types.

Typically a breaker will have both closing springs and opening springs, you load the closing springs either manually with a handle or a small motor in the breaker, that loads the close spring. Usually when the close springs are fully charged a small prop latch engages holding them in that state until you push the close button, with moves the latch, releasing the springs to close the breaker. The act of the breaker closing also charges the trip springs and engaging the trip latch so the breaker will open when the trip latch is moved by either pushing the trip button, or from an automatic trip signal.

Proper adjustment of all of these devices is essential to the proper operation of the breaker.
 
Jraef

Jraef

Moderator, OTD
Staff member
Location
San Francisco Bay Area, CA, USA
Occupation
Electrical Engineer
To Zog's point, the Closing process charges a spring that has sufficient mechanical power to CLOSE the breaker fast enough and hard enough to avoid contact bounce, PLUS charge the spring that OPENS the breaker. The Opening spring needs less energy, but you do NOT need to re-charge the spring with the crank to be able to Open the breaker. The Opening spring is ALWAYS available to open the breaker if it is closed. That's the nature of a breaker.
 
zog

zog

Senior Member
Location
Charlotte, NC
Jraef said:
To Zog's point, the Closing process charges a spring that has sufficient mechanical power to CLOSE the breaker fast enough and hard enough to avoid contact bounce, PLUS charge the spring that OPENS the breaker. The Opening spring needs less energy, but you do NOT need to re-charge the spring with the crank to be able to Open the breaker. The Opening spring is ALWAYS available to open the breaker if it is closed. That's the nature of a breaker.
Click to expand...

Right, and you can see the difference,the grey springs are closing springs, the smaller zinc springs on the far left and right of the photo are the trip springs.

oper mech.jpg
 
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Strathead

Senior Member
Location
Ocala, Florida, USA
Occupation
Electrician/Estimator/Project Manager/Superintendent
weressl said:
You CAN'T close the breaker, even if it has sufficient stored energy for that purpose, if after closing there is insufficient stored energy remaining to OPEN the breaker. In other words the stored amount needs to be sufficient to close AND open.
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If there is not enough energy to "open" the breaker's then you didn't have enough energy to close it in the first place. You have to overcome the force of springs that are inherently in place to open the breaker, during the closing operation. If the breaker is closed and the mechanical operation characteristics of the breaker have not failed, (springs, bearings, trip paddles etc.) then the breaker, always has enough stored energy to open for its rated AIC, even gravity works toward opening. It is like the normally open contacts of an electrically held contactor. Remove electricity and the contacts are open, period.

For the record, I actually know what I am talking about here (for once:)), having worked in the largest Naval circuit breaker overhaul facility for Nuclear Submarines, at Mare Island Navel Shipyard for 8 years.
 
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