we have an old style fuse-box,and one of the circuits failed,
however the fuse wasn't visibly blown.it still looked the same.
2007-05-25 16:40:31 · 7 answers · asked by herb 1 in Science & Mathematics ➔ Engineering
All of the above the answers are correct. I would like to add that corrosion on the metal surfaces that the fuse makes contact with causes excessive heating of the fuse and can lead to its premature failure even in a no-overload situation.
Also, consider what was on the circuit the fuse was protecting. Don't forget that motors/refrigeration compressors draw anywhere from 30 - 100 amps for a brief instant as they start. Therefore, the use of motors on a circuit over time could theoretically "weaken" a typical 15 or 20 amp fuse.
Fuses that do not look visibly "blown" were not victims of a large overload situation. I would inspect the fuse box for corrosion and replace the fuse with another of the same rating. It's unlikely that a serious fault occurred considering that the fuse was old and it didn't show any signs of a serious overload situation. (i.e. blackening of the glass)
2007-05-26 19:39:29 · answer #1 · answered by Logan U 2 · 0⤊ 0⤋
A fuse is a simple device that doesn't wear-out over time. It may have been damaged by periodic surges or other load conditions that approached its minimum melting point.
You can not see the entire fuse element through the viewing window. Take the fuse out and test it with a continuity tester. If it tests good, then it is possible that you have some wiring that broke, disconnecting the circuit without causing a short.
If it tests bad, then you either have a short in the wiring or were trying to run too many things on that circuit. DO NOT just put in a higher rated fuse. The wiring was designed for a specific fuse. If you oversize the fuse, it will not protect the wiring and you can create a fire hazard.
2007-05-26 10:19:07 · answer #2 · answered by Thomas C 6 · 1⤊ 0⤋
If you're talking about the screw-in, Edison base type of plug fuses, it's possible for the conductor to melt through behind the viewing disc, rather than in front of it where you can see the gap. When that happens, the fuse looks OK, but the lack of circuit continuity lets you know that the fuse has blown. Age has nothing to do with it.
2007-05-25 16:50:39 · answer #3 · answered by nickdmd 3 · 1⤊ 0⤋
Yes, a fuse can fail due to age, but it's pretty rare and usually only happens when the circuit has been drawing rated current.
2007-05-25 17:08:07 · answer #4 · answered by Helmut 7 · 1⤊ 0⤋
Yes and no. If you mean fuse then no they will always work under the rated. If you mean breaker yes they need replace once every 25years. As they can stick open.(what others have said i would ask the manufacture)
My uncles house burned 50% down and not one of the breakers popped. If you really want protection from arks and not just overload try a "arc fault breaker". Myself i have never used them so please do some research.
2007-05-25 16:59:43 · answer #5 · answered by Yoho 6 · 1⤊ 2⤋
yes, ageing effect reduce the current carrying capacity of the fuses.
2007-05-25 20:17:49 · answer #6 · answered by vijansingh 3 · 0⤊ 1⤋
an older fuels fails when it gets to hot and the wire burns out. If you used it enough, it could have melted slowly and failed, rather than having obvious dramatic failure.
2007-05-25 16:44:49 · answer #7 · answered by savage708 3 · 3⤊ 0⤋