Using automotive fuses

[Axtman]

I will occassionally see that people use automotive 32V fuses instead of 250V fuses in amplifiers. I always use 250V fuses, but what is the argument against using 32V fuses (of the same amperage)?

[g1]

After the fuse blows, it can arc over if the voltage rating is lower than the circuit voltage.

[Axtman]

Thanks g1.

Can an amp fuse (250V) be used for an automobile...but not the other way around? Not that I would. I am a firm believer in using the proper rated stuff.

[g1]

Yes, a higher voltage rating than required is fine.
Similar to capacitor voltage ratings, or resistor wattage ratings, it's ok to exceed the circuit requirements.

[Mick Bailey]

Automotive fuses are rated at DC and some have arc suppression built in, such as having the fusible link under spring tension. AC ratings consider zero-crossing, which reduces the potential for arcing. Hence the reason for DC voltage ratings being much lower than AC (just like switch ratings). Interchangeability depends on the fuse construction, but probably 1 1/4" glass fuses are closer in construction between the types.

[georage]

automotive fuses are usually quick blow. amp fuses are usually slow blow. voltage rating for the amp fuse is likely required for its ul listing. but the voltage rating must be higher than the voltage input to the device

[georage]

a voltage rating of double the input voltage is nice. if the mains voltage is 120, then a 250v fuse is great. cara use 12v dc so 32v would be great for cars

[Axtman]

The reason for my question is I saw some 'know-it-all' on another forum say that he has been using automotive fuses for years without any problems.

[The Dude]

Doing something that's not recommended doesn't make it right.

[DrGonz78]

Like wrapping an open fuse with foil from your cigarette box in the middle of your band’s second gig that night. I was only following the advice of some drunk guy at the bar. It worked at least. But don’t do it.

[The Dude]

Also, if fuse voltage didn't matter, why would they bother stamping it on the fuse?

[Axtman]

So you are saying that I should not put a penny behind the blown fuse in my houses fuse box? Well I've been doing that for years without any problems!!! ;-)

[Tom Phillips]

So you are saying that I should not put a penny behind the blown fuse in my houses fuse box? Well I've been doing that for years without any problems!!! ;-)

Eventually, there will no problems with the house at all. That is, after it burns down.

[Axtman]

Fuse replacement guide.

[Axtman]

One of the first things I do before I plug in a new (used) piece of equipment is to check the fuse(s). You would not believe how many times I find automotive fuses. I have a box of those fuses. I also visually inspect and test the fuses. You would also not believe how many times I have seen a good fuse that does not have continuity.

BTW, I always start by plugging it into a dim buld limiter.