How big of a fuse do ya think?
03-29-2006, 11:46 AM
#12
Originally Posted by peemoeller
I am just in the process of upgrading my system to about 1500 watts rms / 3000 watts max. I have upgraded the "big 3" and my alternator produces about 180 amps. Two questions:
1. What amperage fuse is sufficient/ideal to use from the battery? Is there a way to calculate?
2. Is it best the fuse each amp after the power distribution block? for example, one amp I have is rated:
Current consumption = 31.0 amps at continous power, 4ohms and
Average current drawn = 7.3 amps at 2ohms.
What sized line fuse would I intall for this amp?
Thanks again for any suggestions & help!!! (I guess it's actally 4 questions)
1. What amperage fuse is sufficient/ideal to use from the battery? Is there a way to calculate?
2. Is it best the fuse each amp after the power distribution block? for example, one amp I have is rated:
Current consumption = 31.0 amps at continous power, 4ohms and
Average current drawn = 7.3 amps at 2ohms.
What sized line fuse would I intall for this amp?
Thanks again for any suggestions & help!!! (I guess it's actally 4 questions)
This will answer your questions
http://www.bcae1.com/wire.htm
03-29-2006, 12:20 PM
#13
Originally Posted by Sr SQ
pssssst. I have a secret. www.canadiancaraudio.com/online/search.php
03-29-2006, 06:45 PM
#16
Yankee
Join Date: Oct 2003
Posts: 3,599
your fuse you use on your power wire should be based on how much power the wire you are useing can handle . not how much power you are useing.
The fuse by the battery is simply for the wire itself, not the combined fuse rating of the amps. I have 1/0 and I have a 250 anl fuse on it, and I'm only running a rockford T10001bd, no problems.
A much better aproach, would be to actually understand what the wire can handle. opposed to just adding up the fuses on the amps. and 1/0's limit is about 350 AMPS...
The fuse by the battery is simply for the wire itself, not the combined fuse rating of the amps. I have 1/0 and I have a 250 anl fuse on it, and I'm only running a rockford T10001bd, no problems.
A much better aproach, would be to actually understand what the wire can handle. opposed to just adding up the fuses on the amps. and 1/0's limit is about 350 AMPS...
A fuse is a protective device, it protects humans and equipment, it is there to prevent damage. What is the correct fuse size, well that depends NOT ON THE WIRE SIZE but on what needs protecting. The systems maximum DESIGN current draw is exactly that, so if the system draws more current than expected there is a problem and a fuse should be there to protect humans and equipment. A 0/1 guage wire can pass many hundeds of amps, most guys will put in a larger power line than is needed for their stereo, do not put in a larger fuse because of a fat wire.
A fuse in an amp is there to limit damage to the amp if there is an internal failure. They should only blow if there is a problem.
A fuse by the battery is to limit the total current draw to the stereo system. It is there to protect the cars electrical system not the stereo equipment (the amp/ speaker could well be toast in a failure enough to smoke a fuse).
Now if you under fuse the battery fuse (smaller than max current draw you could protect the equipment but you could also find SPL slightly limited.
All fuses will allow large current flows for brief periods of time (where a 40 amp fuse will allow 100 amps to pass) but the higher the current the faster the blow (inverse current law).
Most amp manufactuerers will reccomend fuse sizes as well.
03-29-2006, 07:38 PM
#17
Originally Posted by JohnVroom
Holy significant misconceptions Batman!
A fuse is a protective device, it protects humans and equipment, it is there to prevent damage. What is the correct fuse size, well that depends NOT ON THE WIRE SIZE but on what needs protecting. The systems maximum DESIGN current draw is exactly that, so if the system draws more current than expected there is a problem and a fuse should be there to protect humans and equipment. A 0/1 guage wire can pass many hundeds of amps, most guys will put in a larger power line than is needed for their stereo, do not put in a larger fuse because of a fat wire.
A fuse in an amp is there to limit damage to the amp if there is an internal failure. They should only blow if there is a problem.
A fuse by the battery is to limit the total current draw to the stereo system. It is there to protect the cars electrical system not the stereo equipment (the amp/ speaker could well be toast in a failure enough to smoke a fuse).
Now if you under fuse the battery fuse (smaller than max current draw you could protect the equipment but you could also find SPL slightly limited.
All fuses will allow large current flows for brief periods of time (where a 40 amp fuse will allow 100 amps to pass) but the higher the current the faster the blow (inverse current law).
Most amp manufactuerers will reccomend fuse sizes as well.
A fuse is a protective device, it protects humans and equipment, it is there to prevent damage. What is the correct fuse size, well that depends NOT ON THE WIRE SIZE but on what needs protecting. The systems maximum DESIGN current draw is exactly that, so if the system draws more current than expected there is a problem and a fuse should be there to protect humans and equipment. A 0/1 guage wire can pass many hundeds of amps, most guys will put in a larger power line than is needed for their stereo, do not put in a larger fuse because of a fat wire.
A fuse in an amp is there to limit damage to the amp if there is an internal failure. They should only blow if there is a problem.
A fuse by the battery is to limit the total current draw to the stereo system. It is there to protect the cars electrical system not the stereo equipment (the amp/ speaker could well be toast in a failure enough to smoke a fuse).
Now if you under fuse the battery fuse (smaller than max current draw you could protect the equipment but you could also find SPL slightly limited.
All fuses will allow large current flows for brief periods of time (where a 40 amp fuse will allow 100 amps to pass) but the higher the current the faster the blow (inverse current law).
Most amp manufactuerers will reccomend fuse sizes as well.
Mark
03-29-2006, 08:34 PM
#18
Yankee
Join Date: Oct 2003
Posts: 3,599
I am putting too fine a point on this, but why protect a wire? It is the entire system downstream that is to be isolated by the fuse opening (the only thing salvageable might be the wire though)
A circuit breaker or a fuse is there to protect upstream components as well from the deranged downstream components (they are already damaged from the fuses point of reference) so limiting the of damage is an important role.
general rule
fuses in equipment limit or minimize the damage in the equipment
fuses under hood protect the car and the humans from the stereo malfunction
A circuit breaker or a fuse is there to protect upstream components as well from the deranged downstream components (they are already damaged from the fuses point of reference) so limiting the of damage is an important role.
general rule
fuses in equipment limit or minimize the damage in the equipment
fuses under hood protect the car and the humans from the stereo malfunction
Last edited by JohnVroom; 03-29-2006 at 09:02 PM. Reason: cause i screwed up my post...duh
03-29-2006, 09:30 PM
#19
0 Watt CAFz'r
Join Date: Mar 2006
Posts: 49
Originally Posted by JohnVroom
I am putting too fine a point on this, but why protect a wire? It is the entire system downstream that is to be isolated by the fuse opening (the only thing salvageable might be the wire though)
A circuit breaker or a fuse is there to protect upstream components as well from the deranged downstream components (they are already damaged from the fuses point of reference) so limiting the of damage is an important role.
general rule
fuses in equipment limit or minimize the damage in the equipment
fuses under hood protect the car and the humans from the stereo malfunction
A circuit breaker or a fuse is there to protect upstream components as well from the deranged downstream components (they are already damaged from the fuses point of reference) so limiting the of damage is an important role.
general rule
fuses in equipment limit or minimize the damage in the equipment
fuses under hood protect the car and the humans from the stereo malfunction
Installman
03-29-2006, 09:32 PM
#20
50 Watt CAFz'r
Join Date: Mar 2006
Posts: 50
Originally Posted by JohnVroom
I am putting too fine a point on this, but why protect a wire? It is the entire system downstream that is to be isolated by the fuse opening (the only thing salvageable might be the wire though)
A circuit breaker or a fuse is there to protect upstream components as well from the deranged downstream components (they are already damaged from the fuses point of reference) so limiting the of damage is an important role.
general rule
fuses in equipment limit or minimize the damage in the equipment
fuses under hood protect the car and the humans from the stereo malfunction
A circuit breaker or a fuse is there to protect upstream components as well from the deranged downstream components (they are already damaged from the fuses point of reference) so limiting the of damage is an important role.
general rule
fuses in equipment limit or minimize the damage in the equipment
fuses under hood protect the car and the humans from the stereo malfunction
basically over sizing fuses is asking for problems, your gonna wait for 350 amps of draw before you let the fuse blow?
7018 5/32 (equivlent to an 8 gauge wire) welding rods melts at 145 amps 19.2 volts
average car battery 12-14 volts 500+ amps how long do you think that 1/0 will last under that condition?
