Why do we still use fuses? Question, not a statement!

[hockeyoligist2]

I work for a sewer company, 20 different plants, hundreds of different fuses. I cant carry all of them on my truck. What advantage does a fuse have over a circuit breaker? Once you find the problem, you can reset the circuit breaker. If it is a fuse and you don't have a spare you have to go get one.

 

[augie47]

In general terms, I think their "advantage" comes from current limiting capability. There can an advantage in term of starter damage in fault situations as well as general safety in reducing fault current levels.

 

[Pierre C Belarge]

What about cost and size of disconnect enclosures?

 

[cadpoint]

I'm not going to try to recall all the correct terms and talk correctly about these terms so I will only throw out a web page of a major manufacture of fuses and Just start: a Layman description

Fuses gives the user the desired application above and beyond what a average breaker does.
Large Motors are usually fused because their own usuage and application determine something a average breaker can't handle becuase of the way a motor uses power!

This page is not just limited to Fuses FYI (It has been posted here before)
Copper bussmann.

Enjoy

Sorry I forgot, some articles are pay as you Go, I forgot that , Sorry

 

[hillbilly1]

I think they are also better at motor protection, since they are thermal activated, motor starting current is not as much an issue where the magnetic trip function of a circuit breaker may cause problems. Also current is not transfered through a small set of contacts like in a breaker.

 

[zog]

I think they are also better at motor protection, since they are thermal activated, motor starting current is not as much an issue where the magnetic trip function of a circuit breaker may cause problems.

Just like fuses, there are many different types of breakers for different applications. Use the wrong type of either and you will have issues.

Also current is not transfered through a small set of contacts like in a breaker.

But rather through a even smaller element.

 

[zog]

I work for a sewer company, 20 different plants, hundreds of different fuses. I cant carry all of them on my truck. What advantage does a fuse have over a circuit breaker? Once you find the problem, you can reset the circuit breaker. If it is a fuse and you don't have a spare you have to go get one.

Initial cost - Advantage fuse
Replacement or resetting time - Advantage breaker
Replacement or resetting costs - Advantage breaker
Flexibility to change with system changes - Advantage breaker
Clearing time - Advantage current limiting fuse
Interuption capability - Advantage fuse
Protection from single phasing loads - Advantage breaker
Coordination ease with other OCPD's - Advantage breaker (w. electronic trip units)
Communication capability - Advantage breaker

 

[hillbilly1]

But rather through a even smaller element.

Very true, for the thermal portion of the breaker trip mechanism.

 

[Jraef]

Initial cost - Advantage fuse
Replacement or resetting time - Advantage breaker
Replacement or resetting costs - Advantage breaker
Flexibility to change with system changes - Advantage breaker
Clearing time - Advantage current limiting fuse
Interruption capability - Advantage fuse
Protection from single phasing loads - Advantage breaker
Coordination ease with other OCPD's - Advantage breaker (w. electronic trip units)
Communication capability - Advantage breaker

Nicely done.

Add:
Ability to signal status - Advantage breaker
Ability to operate remotely - Advantage breaker
Use in field SCCR rating coordination - Advantage fuse
Ability to protect semiconductor components (SCRs, Diodes etc.) - Advantage fuse (similar to Clearing time above, but slightly different)

 

[Jraef]

Very true, for the thermal portion of the breaker trip mechanism.

I think he was meaning that the way a fuse works is to pass all of the current through a very small meltable metal strip, which is MUCH smaller than a set of contacts or a thermal trip element.

 

[brian john]

Every facility that utilizes fuses should have an up to date fuse cabinet. Now if it is 2:00 AM and you need a specific fuse call me For a GOOD price I have it.

 

[Mike01]

Fuses

Fuses

I like fuses but that's just me it all depends on the installation, some big advantages of breakers are usually smaller footprint for distribution sections, reset-a-sbility, easier to incorporate GFI protectoin etc., fuses less maintenance you can install and walk away with minimal maintenance as related to a circuit breaker, current limiting ability, ease of coordination espically with the new code requirements, but it all depends on the installation, facility, and sometimes the owner, no mater what is selected the have advantages and disadvantages, some will argue one over the other but fuses are making a comeback...IMO....

 

[Prene13]

Fuses will trip alot sooner then breakers (1/4 to 1/2 second sooner). Doesnt seem like a lot but if i got tied up on a circuit i would rather there be a fuse.

 

[nakulak]

have you ever heard of a fuse failing to open under a suitable fault condition ?

 

[Doug S.]

I think zog, and jraef summed things up well.

I'll add I enjoy the ease of use a breaker allows but in some situation like the ability to know a fuse hasn't been reset 1000 times before I get a call to look at something.

I use the number of a thousand figuratively and literally!

Doug S.

 

[SAC]

It seems to me that fuses are quite appropriate for situations where the equipment design is such that an overload should not occur except due to a fault in the equipment. Fuses, particularly small ones, are much more compact and generally more cost effective than breakers. Why uses a breaker in a situation where it would not trip unless there is a fault in the equipment, which by reason of the fault already requires repair of the equipment (likely more substantial than a fuse replacement)? Note that I'm mostly talking about applications "inside the box" here.

 

[jim dungar]

Fuses will trip alot sooner then breakers (1/4 to 1/2 second sooner).

Says who?

Doesn't it depend on the amount of current flowing doesn't it?

Not many molded case circuit breakers take a 1/4 second to open. I know of even fewer that take 1/2 second.

Be careful when comparing fuses and circuit breakers. Power Circuit Breakers are entirely different animals than are Molded Case Breakers, it seems most fuse manufacturers like to compare their products to power breakers.

 

[cadpoint]

Gezz I miss read the OP .... I hate when that happens !:grin:

 

[quogueelectric]

Fuses will trip alot sooner then breakers (1/4 to 1/2 second sooner). Doesnt seem like a lot but if i got tied up on a circuit i would rather there be a fuse.

I just want you to be aware that it would not be realistic for you getting hung up to trip any fuse. You have a better chance with gfci protection if you conduct to ground.

 

[charlie b]

Coordination ease with other OCPD's - Advantage breaker (w. electronic trip units)

Coordination ease with other OCPD's - Advantage fuse (when the breakers are molded case - no electronic trip units).