# What Is the Difference Between a Breaker and a Fuse?



## Paul123 (Feb 10, 2020)

Hi Guys, 

What Is the Difference Between a Breaker and a Fuse? because I'm not entirely sure and I've been asked this question but I couldn't answer in detail.


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## Wirenuting (Sep 12, 2010)

Paul123 said:


> Hi Guys,
> 
> What Is the Difference Between a Breaker and a Fuse? because I'm not entirely sure and I've been asked this question but I couldn't answer in detail.



One is broke and the other fused together. 


Welcome to ET
Please take the time to finish filling out your profile.


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## CWL (Jul 7, 2020)

Sometimes, albeit rarely, a fuse will have enough pixie dust left inside of it to ohm good with a DMM, but not carry current to the device.


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## gpop (May 14, 2018)

Paul123 said:


> Hi Guys,
> 
> What Is the Difference Between a Breaker and a Fuse? because I'm not entirely sure and I've been asked this question but I couldn't answer in detail.


Fuse is one time. Breaker is reset-able and with out knowing your electrical background its not worth getting any deeper into details you may or may not understand.


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## Wirenuting (Sep 12, 2010)

CWL said:


> Sometimes, albeit rarely, a fuse will have enough pixie dust left inside of it to ohm good with a DMM, but not carry current to the device.


Even more so on replaceable links were they reuse the silica.


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## canbug (Dec 31, 2015)

More often then not, a fuse will open quicker but breaker but technology has caught up and some are now faster than a fuses.

Tim


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## Bird dog (Oct 27, 2015)

canbug said:


> More often then not, a fuse will open quicker but breaker but technology has caught up and some are now faster than a fuses.
> 
> Tim


HACR ckt breakers were a way for breaker companies to compete with fuse companies.


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## Wardenclyffe (Jan 11, 2019)

Close a Breaker,

Open a Valve,...


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## just the cowboy (Sep 4, 2013)

Wardenclyffe said:


> Close a Breaker,
> 
> Open a Valve,...


Then what The panel floods with water and goes boom


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## Dennis Alwon (May 9, 2009)

Paul123 said:


> Hi Guys,
> 
> What Is the Difference Between a Breaker and a Fuse? because I'm not entirely sure and I've been asked this question but I couldn't answer in detail.


A breaker and a fuse are both an overcurrent protective device. As mentioned fuses would tend to open the circuit faster than breakers thus they were spec'ed for jobs where the fast opening of a circuit was critical. They do basically the same thing-- they protect the circuit from over current, short circuit and ground fault.


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## 99cents (Aug 20, 2012)

A breaker is an on/off switch that sometimes opens the circuit before the explosion.


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## Wirenuting (Sep 12, 2010)

99cents said:


> A breaker is an on/off switch that sometimes opens the circuit before the explosion.



Don’t tell our safety manager that. He KNOWS that breakers are not switches. 
Switches are switches... 
He also turns the main off at home to change bulbs, just in case.


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## CWL (Jul 7, 2020)

Wirenuting said:


> Don’t tell our safety manager that. He KNOWS that breakers are not switches.
> Switches are switches...
> He also turns the main off at home to change bulbs, just in case.


Sounds kind of like a safety guy at a place I used to work at. Flagged me down because there was a puddle of water _*NEXT TO*_ the end of an extension cord. I walked over to the outlet it was plugged into 15 feet away and unplugged it. He threatened to write me up for a lockout tagout violation. He got fired about a year later and I when I left more than a year after that it was on my own terms with well wishes.:vs_laugh:


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## paulengr (Oct 8, 2017)

canbug said:


> More often then not, a fuse will open quicker but breaker but technology has caught up and some are now faster than a fuses.
> 
> Tim



Not anything more: semiconductor fuses trip in 1-2 ms. The only breakers that fast are solid state ones but those are really more of a soft start than a breaker. Fuses also have nearly unlimited interrupting current but not breakers. To get above 65 kA “breakers” have fuses built in. Standard fuses trip in 4 ms while the fastest small breakers trip in 16-20 ms.


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## paulengr (Oct 8, 2017)

Wirenuting said:


> Don’t tell our safety manager that. He KNOWS that breakers are not switches.
> Switches are switches...
> He also turns the main off at home to change bulbs, just in case.



Large distribution and transmission level breakers are called switches. At medium voltage electronic switches (SCRs, GCTs, HVIGBTs) are called valves.


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## MechanicalDVR (Dec 29, 2007)

canbug said:


> More often then not, a fuse will open quicker but breaker but technology has caught up and some are now faster than a fuses.
> 
> Tim



If sensitive equipment is involved a fuse is often the best way to go.


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## MechanicalDVR (Dec 29, 2007)

just the cowboy said:


> Then what The panel floods with water and goes boom


:vs_laugh::vs_laugh:

Seen it!


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## MechanicalDVR (Dec 29, 2007)

99cents said:


> A breaker is an on/off switch that sometimes opens the circuit before the explosion.



"Sometimes" being the key operative phrase!


FPE and Zinsco the opposite more often than not!


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## mofos be cray (Nov 14, 2016)

How is it that there are 2 pages of responses to this when we haven't even solved the notched stud problem? 🤣🤣🤣


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