130amp altERNATOR - what fuse?

[vbstng]

a few questions, im going to run 4 gauge wire, where can i get an inline e fuse for the wire? advanced didnt have one that big? can i use one from the car stereo place? also what amp fuse should i run? i was thinking 200

[Markus]

Hello,
i use on my pa-performance 130 amp alternator a 200 amp fuse. They come original with the alternator.

[godspeed_89]

I use a 150 amp wafer fuse

[vbstng]

i looked and looked, i have the wire, but cant find an inline fuse??

[royalfockhead]

Originally Posted by vbstng

i looked and looked, i have the wire, but cant find an inline fuse??

Look for an ANL fuse and holder.

EDIT:
Here's a complete install package. http://cgi.ebay.com/ebaymotors/87-93...mZ170253001711





.

[hotrodder]

Don't use a fuse. Autozone sells a 150amp circut breaker for @ 26.00

[vbstng]

ill check out the circuit breaker, whats the difference between the 2?
i have all the wiring and stator wiring and ends, i just needed a fuse?

[slo895.0]

Originally Posted by vbstng

ill check out the circuit breaker, whats the difference between the 2?
i have all the wiring and stator wiring and ends, i just needed a fuse?

the circuit breaker is like a reusable fuse. its just like the circuit breakers in your house. it will trip, and you can reset it.

[red89notch]

a fuse will hold TWICE its rated power for 3-5 seconds before blowing, not many people know this. a short is not part of the equasion (sp?)

also if you put 2 fuses side by side (see pic) of 100 amps each to make a 200amp connection it will last longer then a single 200 amp fuse when given 400 amps


a 200 amp fuse will hold 200 amps all day long, it will even hold 250 for a long time.

so think about this your 130 amp alt with a 200 amp fuse isnt very protected if the fuse will hold 400 amps for a few seconds.

and do be honest the only reason i know this is from my dads in car stereo competitions, where your classed by your fuse rating. it works out good when you can pull 200 amps on a 100 amp for a spl burp

[8950HO]

I used a 175amp Mega Fuse and fuse holder with my 130amp 3g.
Ford used a 175amp fuse on some production vehicles so I went with with that size.

I think the company that makes it is called littlefuse.I ordered it through my local auto parts store when I got the part number off the website.

www.littlefuse.com

[An_88_Monster]

actually advance does have a battery/alternator 175 amp fuse. i know cause i work there. in my store it's located on the bottom rack in a small box. i think it has a list price of ~$10. don't quote me for the price.

just thought i'd throw that out there. i actually did not use one on my install. -Sam.

[royalfockhead]

Originally Posted by red89notch

a fuse will hold TWICE its rated power for 3-5 seconds before blowing, not many people know this. a short is not part of the equasion (sp?)

also if you put 2 fuses side by side (see pic) of 100 amps each to make a 200amp connection it will last longer then a single 200 amp fuse when given 400 amps
p://i42.photobucket.com/albums/e318/slc72005/fuse.jpg[/IMG]

a 200 amp fuse will hold 200 amps all day long, it will even hold 250 for a long time.

so think about this your 130 amp alt with a 200 amp fuse isnt very protected if the fuse will hold 400 amps for a few seconds.

and do be honest the only reason i know this is from my dads in car stereo competitions, where your classed by your fuse rating. it works out good when you can pull 200 amps on a 100 amp for a spl burp

Correct me if I'm wrong, but... an alternator's not an audio amp. An amp draws current, an alternator is a source of current. The fuse isn't protecting the alternator, it protects the circuit. Even a small spike can take out alternator diodes. Nothing will protect the alternator, a 175~200a fuse would be good at protecting the circuit from catastrophic failure, like a ground short of that fat 4 gauge wire.

[vbstng]

Originally Posted by royalfockhead

Correct me if I'm wrong, but... an alternator's not an audio amp. An amp draws current, an alternator is a source of current. The fuse isn't protecting the alternator, it protects the circuit. Even a small spike can take out alternator diodes. Nothing will protect the alternator, a 175~200a fuse would be good at protecting the circuit from catastrophic failure, like a ground short of that fat 4 gauge wire.

so in other words the amp is worthless cause the alternator can still fry? what about engine bay fires??

[Fast Eddie D]

Originally Posted by royalfockhead

Correct me if I'm wrong, but... an alternator's not an audio amp. An amp draws current, an alternator is a source of current. The fuse isn't protecting the alternator, it protects the circuit. Even a small spike can take out alternator diodes. Nothing will protect the alternator, a 175~200a fuse would be good at protecting the circuit from catastrophic failure, like a ground short of that fat 4 gauge wire.

You're correct. The fuse is supposed to protect the wiring from a short. The alternator itsself can short and drain the battery. If the alternater has a bad enough short it can cause a fire, and this is really all the fuse is there for, to prevent a fire. The fuse should be as close to the battery as possible, like right on the hot post of the solenoid.

[royalfockhead]

Originally Posted by vbstng

so in other words the amp is worthless cause the alternator can still fry? what about engine bay fires??

Engine fire is what the fuse is protecting against. Like said above, you want the fuse close to the battery, because it's the circuit being protected, not the alternator.
You want the fuse rated higher than the alternator's max output (a 130a 3G will put out 170a under full load), but you want it lower than the circuit (the 4 gauge wire).

Think of it like this... If you had the 4 gauge wire from alt to battery without a fuse and some of the insulation rubbed off of the 4g wire and it shorted to ground, it would take out the alternator, the heat would melt insulation and start taking out other circuits and would most likely cause a fire.

If you had the circuit protected with an inline fuse, the alternator would be toast and the fuse would blow.

I'm not an electrical engineer and could be dead wrong, but this is my understanding of how it works.

[sjd3021]

my 95A PA alt came w/ a 200A fuse. is that to large?

[Mattstang65]

Shade tree electricians can be scary. The purpose of the inline fuse is to protect the wire. Diff size wire has different current carrying ability or limitations, amps are the measuring units for current. It was correct as listed above that a 200 amp fuse will pass 200amps of current all day long. That is a problem if your only using 4 ga wire that is rated at around 160 amps full load (not continuous) carrying ability. That basically means that with 4 Ga wire and a 200amp fuse, if you see 200 amps for any length of time the wire will fail (melt, burn) and the fuse wouldn't blow.

Realistically (sp?), a 130 amp or whatever high amp alt you use will not be pumping out that max amp rating at all times. The alt output will vary depending on load needed. The more acc you have (stereo, elec fans, fuel pump, lights, etc) running at the same time, the higher the alt output will be up to it's max ability. The size of charge wire you use should be based on the alt max output ability, and then based on the wire size you choose the correct fuse protection.

A fuse is the safest and fastest way to protect a circuit. They are very accurate and dependable. Circuit breakers work, but they are not as fast or as dependable, I've seen them fail not tripping soon enough, tripping too early (nuisance trips) and some not trip at all.

I personally chose 2 ga wire for my 130 alt install and protect it with a 175 amp mega fuse. The minimal cost and little extra weight are worth protecting the larger investment I have in the rest of the car.

Check out the amp rating table for single core/battery starter cable.
You can also look under the fuses/breakers tab at fuse holders and breakers. I chose the "mega fuses" and their respective holder because the 175 amp fuses are readily available at the salvage yards, alot of late model cars use them.

http://www.12volt.com.au/redirect.ht...cablewire.html


This is the fuse holder that I use. They can be had cheaper through waytekwire.com.

http://www.electricvehiclesusa.com/p..._p/fh-mega.htm

[Mattstang65]

If your dead set on using the 4ga wire, it would be a good idea to use a 150 amp fuse max, 125 would probably work for you as well. You'd need to find a local shop that rebuilds alternators that can "load" test your alt to see how much output it is truely capable of producing and fuse accordingly.

In any short circuit fault such as the wire getting pinched or the insulation wearing through and grounding out will result in an immediate current spike and resulting blown fuse.

Another helpful site:

http://www.the12volt.com/info/recwirsz.asp

Watts or power = amps x volts

[royalfockhead]

Originally Posted by Mattstang65

If your dead set on using the 4ga wire, it would be a good idea to use a 150 amp fuse max, 125 would probably work for you as well. You'd need to find a local shop that rebuilds alternators that can "load" test your alt to see how much output it is truely capable of producing and fuse accordingly.

In any short circuit fault such as the wire getting pinched or the insulation wearing through and grounding out will result in an immediate current spike and resulting blown fuse.

Good stuff, Matt, but Ford uses 175a mega fuses with 6 awg wire, in cars with 130a rated 3G alternators.
Also, why get the alternator load tested? Do people really use the max output, at anything other than idle? Even a 200a alternator, is only capable of around 100a at idle.
Not trying to argue, I'm in no position to. Just thinking aloud and curious


.

[ksstang]

I guess I need to think about getting a fuse. The guy I got the car from did the 3g upgrade, but there isnt a fuse ANYWHERE on the upgrade. So it goes inline with the BIG wire going from the starter solinoid down to the alternator?

[Mattstang65]

Most don't tax the alt to it's limit, especially in stock vehicles. The 175 fuse that ford uses is mainly for fault protection, I believe, not constant full load carrying ability. Short runs also raise a cables current carrying ability, most modified cars have relocated (trunk mount) batteries. There are alot of factors involved. Fire and its potential scares me, so I always lean toward the safer side or overkill when it comes to protecting against it. Do what you like.

[vbstng]

im going to get the fuse holder and fuse from ELECTRICVEHISLESUSA
thanks everybody, corral has helped once again -)

[Frank91lx]

I bought my fuse and holder here. It is the best price I have found.

http://www.keefeperformance.com/high_amp_fuses.html

[RedSE]

You may want to look at marine fuses and fuse blocks - here's an example



This one is 32 bucks, and holds up to a 250 amp fuse. It's what I used in my 3g upgrade.

Try West Marine or any boat hardware source.

[Frank91lx]

Originally Posted by RedSE

You may want to look at marine fuses and fuse blocks - here's an example



This one is 32 bucks, and holds up to a 250 amp fuse. It's what I used in my 3g upgrade.

Try West Marine or any boat hardware source.

The same thing is on the website I just posted above for $9.99.