Question about fuses not blowing

[RedFred]

14 minutes ago, Skullz said:

Those usually pop when you exceed them by a fair amount before they blow, or when you get a short. You might not be pulling enough power all at once to pop em.

I think there was a discussion on those some time back about how much more it takes for them to blow and you should be using lower rated fuses.

Interesting.

My only experience with a blown fuse in the past was when I went from 50A fuses on stock electrical and a 1200w amp, to a Brutus 3K without swapping fuses. Blew it just about as soon as I turned the volume up.

I was just expecting these fuses to blow in the same manner I guess.

[Reaper]

Honestly I wouldn't worry about it. If they pop then there's a problem.

[Kyblack76]

Well, it would be nice to see if his alt set up is doin work as should also. I would clamp them. Just me. I wouuld have had my fluke clamp on both the second I installed them and turned the truck on. Again, just me. I like knowing.....

[reedal]

56 minutes ago, RedFred said:

It shoots up anytime there isn't a hard bass line.

I would clamp it and make sure you're getting what you paid for since you drop straight to battery resting voltage

[ChevyBoy95]

Just because your voltage is low doesnt mean you are fully tapping your alternators. Check front battery voltage and amplifier voltage under the same conditions under load. I have seen situations where the front was like 13.3v (so the alts werent fully being drawn on), but the rear was like 12.7v and the guy was wondering why he was only pulling 150a from his 300+a alt revved.

[ChevyBoy95]

And about the fuses...

fuses rarely pop are their rating. 200A fuse will take a while to pop with 200A through it. They need time to heat up before they blow as well. Most of the time they do blow is due to a short (500+A), or if you have like a single 150A fuse on a 7k. Reasons why in MECA (?) they can get so much power in a low fuse rating class.

[snafu]

Fuse failures are rated based on current vs. time.  ANL Fuses, like those from Cooper Bussman, have published charts that correspond to fuse failure.  Car Audio fuses are all over the map, based on who actually builds them.

[Wicks]

Fuses are thermal devices, not circuit breakers.

A 100A fuse will not blow at 101A.  As stated above, it takes considerable time and heat to blow them.

They are there for fault protection when a wire gets fully shorted too ground.

The rating on the fuse is what it can safely carry.  If you use a fuse too small for the application, you may not notice any issue and it may not blow initially, BUT it could be a bottleneck for the current and cause some voltage drop.