ASL fuse sizes?
Printed From: the12volt.com
Forum Name: Car Audio
Forum Discription: Car Stereos, Amplifiers, Crossovers, Processors, Speakers, Subwoofers, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=76009
Printed Date: April 29, 2024 at 9:59 AM
Topic: ASL fuse sizes?
Posted By: corey497
Subject: ASL fuse sizes?
Date Posted: April 10, 2006 at 1:59 PM
Im trying to figure out what fuses i will need for my amp installation. I looked at the chart here but is doesent make sence to me beacuse those numbers are almost double what i figured out, so maybe im useing the wrong numbers or maybe someone can correct me, heres the set up, i need to know what size amperage fuses to get between: #1 235 amp alternator to the battery (0 gauge) #2 battery to a 2 farad capasitor thats feeding 2 - 1000 watt amps (0 gauge) # 3 capasitor to the 2 amps (4 gauge) For example the chart says that 1000 watts will pull 160 amps... well i figure: 1000 watts / 12 volts = 83.3 amps can i just get a plain rounded off number??
Replies:
Posted By: Steven Kephart
Date Posted: April 10, 2006 at 2:41 PM
The point of the fuse at the battery is to protect the vehicle from accidental power wire shorting. It is not there to protect your equipment as they should have their own internal fuses for that. So you want to select a fuse size that is just above the maximum amount of current all the equipment attached to that power wire will draw. The best way to figure this is just to add up all the fuse sizes on the equipment, and go somewhere around that number. But it doesn't have to be exact.
Posted By: DYohn
Date Posted: April 10, 2006 at 2:45 PM
Steven Kephart wrote:
The point of the fuse at the battery is to protect the vehicle from accidental power wire shorting. It is not there to protect your equipment as they should have their own internal fuses for that. So you want to select a fuse size that is just above the maximum amount of current all the equipment attached to that power wire will draw.
AND make sure your fuse size is below the maximum current capacity for the power cable gauge size and length of cable run. If your gear requires more current than the cable can safely carry, it's time for bigger cables. ------------- Support the12volt.com
Posted By: the12volt
Date Posted: April 10, 2006 at 3:00 PM
The current draw figures in my chart are based on RMS power of an amplifier with a 50% efficiency rating, hence the difference between my numbers and yours. -------------  the12volt • Support the12volt.com
Posted By: corey497
Date Posted: April 10, 2006 at 3:27 PM
Steven Kephart wrote:
So you want to select a fuse size that is just above the maximum amount of current all the equipment attached to that power wire will draw. The best way to figure this is just to add up all the fuse sizes on the equipment, and go somewhere around that number. But it doesn't have to be exact.
Now see im lost, the amps have 2X25 amp fuses, which means that they will both need a 50 amp fuse between them and the capastior? not 80 or 160? and betwwen the battery and capastior 100 amp not 300amp? What about the alternator??? its supplying not draining at 235 amps, but that still has to be fuse protected...
Posted By: the12volt
Date Posted: April 10, 2006 at 3:42 PM
You didn't mention the model numbers of the amplifiers you have, but they are not putting out 1000 watts each. At 100% efficiency, each amp would produce only 720 watts if it were pulling 50 amps of current at 14.4 volts and at 50% efficiency, each would produce only 360 watts. What amplifiers do you have? ------------- the12volt • Support the12volt.com
Posted By: corey497
Date Posted: April 10, 2006 at 4:04 PM
https://www.pioneerelectronics.com/pna/product/detail/... these are the amps im installing i understand the confusion about the amps but what about my alternator? its not drawing its supplying power to the battery with a 0 gauge wire, but no one has metioned anything about it, it does need to be fused right?
Posted By: hardknocks
Date Posted: April 10, 2006 at 10:08 PM
wire from the alt to ur battery doesn't need to be fused unless u have an isolator then the fuse will have to be to the extra battery you have after the aux. terminal on the Isolator. other than tha tur alt doesn't really need one.
-------------
4-15" RF T2
6-7" RF Component sets
8 Planet Audio 900d
10 Batcap800
1 250 amp alt
1 300 amp alt
2" sound deadner roof,doors,floors
Posted By: haemphyst
Date Posted: April 11, 2006 at 9:01 AM
hardknocks wrote:
wire from the alt to ur battery doesn't need to be fused unless u have an isolator then the fuse will have to be to the extra battery you have after the aux. terminal on the Isolator. other than tha tur alt doesn't really need one.
That is a BAD suggestion. You ALWAYS FUSE EVERY WIRE COMING OFF ANY BATTERY, WITHIN 18 INCHES OF THE BATTERY. You stated your power cable from alt to battery was a 0 gauge. What happens if you are in a minor accident (not enough to total the car), and that cable is compromised in some way? All of a sudden your car is ON FIRE, and now it IS totalled... Fuse it. ------------- It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."
Posted By: hardknocks
Date Posted: April 11, 2006 at 10:15 PM
haemphyst wrote:
That is a BAD suggestion. You ALWAYS FUSE EVERY WIRE COMING OFF ANY BATTERY, WITHIN 18 INCHES OF THE BATTERY. You stated your power cable from alt to battery was a 0 gauge. What happens if you are in a minor accident (not enough to total the car), and that cable is compromised in some way? All of a sudden your car is ON FIRE, and now it IS totalled... Fuse it.
if this where to ever happen then I'm a wiz poor electrician and i don't need top be crimping wires I can asure you that if i were to get into an accident the engine would have to tear into the wire for it to short out. for someone that doesn't have the correct equipment to crimp such large wires then i see where you would say this. but i'm no shade tree installer of electrician. there wouldn't be million dollar equipment flying around fighting for our country. ------------- 4-15" RF T2
6-7" RF Component sets
8 Planet Audio 900d
10 Batcap800
1 250 amp alt
1 300 amp alt
2" sound deadner roof,doors,floors
Posted By: hardknocks
Date Posted: April 11, 2006 at 10:23 PM
also haemphyst i you read what I have and how i ran my alts u will see the 300 amp that goes straight back to the rear batteries does have a anl fuse. and the 250 amp comes from the alt to a Isolator that goes to the main battery then back to the rear batteries and it is fused 15" after the isolator ------------- 4-15" RF T2
6-7" RF Component sets
8 Planet Audio 900d
10 Batcap800
1 250 amp alt
1 300 amp alt
2" sound deadner roof,doors,floors
Posted By: corey497
Date Posted: April 14, 2006 at 4:46 PM
ummm, so any help with the fuses i need?????
Posted By: stevdart
Date Posted: April 14, 2006 at 5:52 PM
Okay...your question was answered a few times, but let's K.I.S.S. - Fuses protect the wire in which they are installed.
- Choose the fuse rating according to the gauge of the wire.
- Fuse every positive power wire.
- The position of the fuse in the power wire should be as close as possible to the source of current. The battery is a source of current; a high amperage storage device.
- Use the fuse ratings shown in Power and Ground Cable Specs.
------------- Build the box so that it performs well in the worst case scenario and, in return, it will reward you at all times.
Posted By: corey497
Date Posted: April 23, 2006 at 5:36 PM
stevdart wrote:
Okay...your question was answered a few times, but let's K.I.S.S.
Well then you point it out to me because i see NO posts saying what amp fuses to use...
Posted By: geepherder
Date Posted: April 23, 2006 at 5:50 PM
Slow down and read again- the very first two responses give you all the info you need.
-------------
My ex once told me I have a perfect face for radio.
Posted By: corey497
Date Posted: April 24, 2006 at 11:07 AM
OK well this is what i gather from the Power and Ground Cable Specs Ill need a 160A (X2) between my amps & cap Ill need a 320A between my battery & cap Ill will need a 235A betwwen my 235A alternator & battery Am i right? im soo ready to pull my hair out. Is there really any difference (except price) in the gold plated fuses?
Posted By: corey497
Date Posted: April 24, 2006 at 11:20 AM
After further research i found that i cant use those exact fuse sizes, so i guess it would be smarter to round down?? 160 ~> 150 320 ~> 300 235 ~> 225
Posted By: stevdart
Date Posted: April 24, 2006 at 1:19 PM
The Power and Ground Cable Specs chart shows fuse values appropriate for wire gauge. You may use the 150 amp fuse in any gauge wire no thinner than 4 gauge (read this as: 150 amp fuse is appropriate for a 4 gauge wire and may not be used in any wire that is smaller). The 300 amp fuse may be used in any wire no thinner than 1/0 gauge. The 225 amp fuse may be used in any wire no thinner than 2 gauge.
-------------
Build the box so that it performs well in the worst case scenario and, in return, it will reward you at all times.
Posted By: corey497
Date Posted: April 25, 2006 at 5:12 PM
I made my mind up on the fuses for the amps, but what about the alternator? Its going to be supplying not drawing. I guess I go with a fuse rated at the peak output of it?? Beacuse, if its putting out peak amps theres problem and rather than anything melt down the fuse will pop... right??
Posted By: stevdart
Date Posted: April 25, 2006 at 10:10 PM
This is the last time I will say it: fuses are chosen for the gauge of wire in which they are placed, not for the device at the end of the wire.
-------------
Build the box so that it performs well in the worst case scenario and, in return, it will reward you at all times.
Posted By: corey497
Date Posted: April 26, 2006 at 4:44 PM
..... and i said im useing 0 gauge. Lets be serious here. The lenth is no longer than about 15 feet. Cant i just get a estimated number? I know what im guessing i just want to see that someone else got around the same number i did. Im looking for help not a run around...
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