What is the proper fuse size to use with my setup. Ive got a
Sony1600w P5 mono amp with an MTX404 thunder connected to its 2nd amp
conectors. My subs off the sony ar 12" kicker CVR's at 4ohms. The
MTX is pushing 4 Orion p6.5's. The setup currently has a 60A fuse that
blows after about 10-15min of use. The fuse was out in before the MTX
was added to the mix so I'm thinking it's not strong enough for the
new setup OR the MTX is causing the blow.

Any suggestion?


THANK YOU!!!

Mitzi

"Mitzi" wrote in message
om...
What is the proper fuse size to use with my setup. Ive got a
Sony1600w P5 mono amp with an MTX404 thunder connected to its 2nd amp
conectors. My subs off the sony ar 12" kicker CVR's at 4ohms. The
MTX is pushing 4 Orion p6.5's. The setup currently has a 60A fuse that
blows after about 10-15min of use. The fuse was out in before the MTX
was added to the mix so I'm thinking it's not strong enough for the
new setup OR the MTX is causing the blow.

Any suggestion?


THANK YOU!!!

Mitzi


X watts/14.4 volts=fuse size in amps

On Sun, 07 Mar 2004 00:09:24 GMT, "Z. Gluhak"
wrote:


"Mitzi" wrote in message
. com...
What is the proper fuse size to use with my setup. Ive got a
Sony1600w P5 mono amp with an MTX404 thunder connected to its 2nd amp
conectors. My subs off the sony ar 12" kicker CVR's at 4ohms. The
MTX is pushing 4 Orion p6.5's. The setup currently has a 60A fuse that
blows after about 10-15min of use. The fuse was out in before the MTX
was added to the mix so I'm thinking it's not strong enough for the
new setup OR the MTX is causing the blow.

Any suggestion?


THANK YOU!!!

Mitzi


X watts/14.4 volts=fuse size in amps




Actually, the equation above assumes 100% amplifier efficiency, which
you'll never see. For class AB amps (such as your MTX404), 50% is a
good estimate of efficiency. For digitial-switching amps (like your
Sony P5), you might get 75%-85%. Considering that your MTX amp alone
has two 25-amp fuses, I think the problem is that you're drawing more
current than a 60A fuse can handle. I can't find the recommended fuse
size for the Sony P5 1600W, but since it's rated at 900W RMS, I'd say
you need at least a 100A fuse just for the Sony (assuming 75%
efficiency). Combine this with the 50A for the MTX, and your main
power lead needs to have at least a 150A fuse or circuit breaker.

Scott Gardner

Z. Gluhak wrote:
"Mitzi" wrote in message
om...

What is the proper fuse size to use with my setup. Ive got a
Sony1600w P5 mono amp with an MTX404 thunder connected to its 2nd amp
conectors. My subs off the sony ar 12" kicker CVR's at 4ohms. The
MTX is pushing 4 Orion p6.5's. The setup currently has a 60A fuse that
blows after about 10-15min of use. The fuse was out in before the MTX
was added to the mix so I'm thinking it's not strong enough for the
new setup OR the MTX is causing the blow.

Any suggestion?


THANK YOU!!!

Mitzi



X watts/14.4 volts=fuse size in amps

Not so fast there, hoss. It sounds to me like he's talking about his
main power wire. In that case, the fuse should be appropriate to the
power handling capability of his wire. To know that, we need to know the
gauge and length of the run.

The fuse on the main power wire is to protect the power wire - or more
importantly, prevent fire should that wire short out. It has nothing to
do with the current draw of the system.

--
thelizman "I didn't steal the FAQ either"

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http://www.mobileaudio.com/rac-faq. It contains over a decade and
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other than usenet without the express written permission of the author
is forbidden.

Scott Gardner wrote:
On Sun, 07 Mar 2004 00:09:24 GMT, "Z. Gluhak"
wrote:

Actually, the equation above assumes 100% amplifier efficiency, which
you'll never see. For class AB amps (such as your MTX404), 50% is a
good estimate of efficiency. For digitial-switching amps (like your
Sony P5), you might get 75%-85%. Considering that your MTX amp alone
has two 25-amp fuses, I think the problem is that you're drawing more
current than a 60A fuse can handle. I can't find the recommended fuse
size for the Sony P5 1600W, but since it's rated at 900W RMS, I'd say
you need at least a 100A fuse just for the Sony (assuming 75%
efficiency). Combine this with the 50A for the MTX, and your main
power lead needs to have at least a 150A fuse or circuit breaker.


The fuse on the main power wire should be rated according to the gauge
and length of the power wires run. It has nothing to do with the current
draw of the amplifiers.

I also suggest everyone put a cheap auto-parts store ammeter gauge on
their power wires, and watch how much (dare I say....little) current
your amps typically draw.

Fuses are as much an indicator of amplifier power as chassis size,
color, brand, or the size of the installers cock in cm.


--
thelizman "I didn't steal the FAQ either"

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http://www.mobileaudio.com/rac-faq. It contains over a decade and
a half of knowledge.

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teamROCS Car Audio News http://www.teamrocs.com/news/
"It's about the music, stupid"

This post is Copyright (C) 2004. Reproduction of its content anywhere
other than usenet without the express written permission of the author
is forbidden.

On Mon, 08 Mar 2004 12:00:09 -0500, thelizman
wrote:

Scott Gardner wrote:
On Sun, 07 Mar 2004 00:09:24 GMT, "Z. Gluhak"
wrote:

Actually, the equation above assumes 100% amplifier efficiency, which
you'll never see. For class AB amps (such as your MTX404), 50% is a
good estimate of efficiency. For digitial-switching amps (like your
Sony P5), you might get 75%-85%. Considering that your MTX amp alone
has two 25-amp fuses, I think the problem is that you're drawing more
current than a 60A fuse can handle. I can't find the recommended fuse
size for the Sony P5 1600W, but since it's rated at 900W RMS, I'd say
you need at least a 100A fuse just for the Sony (assuming 75%
efficiency). Combine this with the 50A for the MTX, and your main
power lead needs to have at least a 150A fuse or circuit breaker.


The fuse on the main power wire should be rated according to the gauge
and length of the power wires run. It has nothing to do with the current
draw of the amplifiers.

I oversimplified my post, but I believe you have as well. It's true
that the main power fuse is used to protect the wiring first and
foremost, but it must ALSO be of adequate size when taking into
account the amplifiers that are connected downstream. If you believe
the RMS numbers of his amps (900W and 200W), I don't think a single
60A fuse in the main power lead is adequate for his needs. The fact
that it's blowing after 10 or 15 minutes of sustained playing makes
sense if the fuse is significantly undersized. I don't know how
loudly he was playing his music, or what type of music it was, but
even assuming relatively efficient amps, 60A isn't even in the
ballpark for 1100WRMS.


I also suggest everyone put a cheap auto-parts store ammeter gauge on
their power wires, and watch how much (dare I say....little) current
your amps typically draw.

I wouldn't suggest doing this with a meter you care much about. Even
my Fluke is limited to 10A in current mode. At reasonable listening
levels, the average current draw will likely be much less than people
expect, but it can still be pretty substantial.


Fuses are as much an indicator of amplifier power as chassis size,
color, brand, or the size of the installers cock in cm.

True, fuses dont' tell the whole story about an amplifier's power
capability, but they have to be at least adequate. Looking at a
reputable manufacturer's amplifiers, you won't see a 1000W amp with a
20A fuse.

Scott Gardner



--
thelizman "I didn't steal the FAQ either"

Before you ask a question, check the FAQs for this newsgroup at
http://www.mobileaudio.com/rac-faq. It contains over a decade and
a half of knowledge.

teamROCS Car Audio Forums http://www.teamrocs.com/caraudio/
teamROCS Car Audio News http://www.teamrocs.com/news/
"It's about the music, stupid"

This post is Copyright (C) 2004. Reproduction of its content anywhere
other than usenet without the express written permission of the author
is forbidden.

Scott Gardner wrote:

I oversimplified my post, but I believe you have as well.

Negative, Ghostrider. The pattern is full.

It's true
that the main power fuse is used to protect the wiring first and
foremost, but it must ALSO be of adequate size when taking into
account the amplifiers that are connected downstream.

Uhm, no. The only consideration for fusing the main power wire is the
current carrying capacity of the wire itself. If the amplifiers are
going to draw more than the wire is rated for, then the installer needs
to select a larger gauge of wire.

Stuffing any old fuse in there is half-assed.

I wouldn't suggest doing this with a meter you care much about. Even
my Fluke is limited to 10A in current mode.

What part of "gauge" escaped your attention?

--
thelizman "I didn't steal the FAQ either"

Before you ask a question, check the FAQs for this newsgroup at
http://www.mobileaudio.com/rac-faq. It contains over a decade and
a half of knowledge.

teamROCS Car Audio Forums http://www.teamrocs.com/caraudio/
teamROCS Car Audio News http://www.teamrocs.com/news/
"It's about the music, stupid"

This post is Copyright (C) 2004. Reproduction of its content anywhere
other than usenet without the express written permission of the author
is forbidden.

On Wed, 10 Mar 2004 20:52:53 -0500, thelizman
wrote:

Scott Gardner wrote:

I oversimplified my post, but I believe you have as well.

Negative, Ghostrider. The pattern is full.

It's true
that the main power fuse is used to protect the wiring first and
foremost, but it must ALSO be of adequate size when taking into
account the amplifiers that are connected downstream.

Uhm, no. The only consideration for fusing the main power wire is the
current carrying capacity of the wire itself. If the amplifiers are
going to draw more than the wire is rated for, then the installer needs
to select a larger gauge of wire.

Stuffing any old fuse in there is half-assed.


I should have asked what gauge wire he was using, that's true. It's
entirely possible, however, that he's already running adequate wire
gauge, but simply has an undersized fuse installed. He could be
running 1/0 wire or larger, but with his amplifiers, a 60A fuse is
still going to blow.

And I get your point about the main power fuse being there just to
protect the wiring, but I still take the downstream loads into
consideration. Some people use larger-gauge wire than they currently
need, because it's /not that much more expensive/looks cool/allows for
future expansion without rewiring/or whatever. 1/0 wire has a
capacity of about 350A, but I'm not going to use a 350A fuse/breaker
in the main power lead just based on the wire size. If he's using 1/0
wire, and all his downstream loads total 150A or so, I think a 150A
fuse/breaker in the main power lead is appropriate. It's still going
to protect the main wiring, and it will probably cost less than a 350A
fuse or breaker.

Realistically, he's probably running 4-gauge, which is still adequate
for his needs. If that's the case, he just needs a larger fuse.
Since his big Sony amp was the original amp in the install, I bet he's
not running 8-gauge.


I wouldn't suggest doing this with a meter you care much about. Even
my Fluke is limited to 10A in current mode.

What part of "gauge" escaped your attention?

Sorry, you're absolutely right. I read "gauge" and thought "meter".


Scott Gardner



--
thelizman "I didn't steal the FAQ either"

Before you ask a question, check the FAQs for this newsgroup at
http://www.mobileaudio.com/rac-faq. It contains over a decade and
a half of knowledge.

teamROCS Car Audio Forums http://www.teamrocs.com/caraudio/
teamROCS Car Audio News http://www.teamrocs.com/news/
"It's about the music, stupid"

This post is Copyright (C) 2004. Reproduction of its content anywhere
other than usenet without the express written permission of the author
is forbidden.

What would the formula be to calculate main power run fuse size based on
gauge and length?


"thelizman" wrote in message
...
Z. Gluhak wrote:
"Mitzi" wrote in message
om...

What is the proper fuse size to use with my setup. Ive got a
Sony1600w P5 mono amp with an MTX404 thunder connected to its 2nd amp
conectors. My subs off the sony ar 12" kicker CVR's at 4ohms. The
MTX is pushing 4 Orion p6.5's. The setup currently has a 60A fuse that
blows after about 10-15min of use. The fuse was out in before the MTX
was added to the mix so I'm thinking it's not strong enough for the
new setup OR the MTX is causing the blow.

Any suggestion?


THANK YOU!!!

Mitzi



X watts/14.4 volts=fuse size in amps

Not so fast there, hoss. It sounds to me like he's talking about his
main power wire. In that case, the fuse should be appropriate to the
power handling capability of his wire. To know that, we need to know the
gauge and length of the run.

The fuse on the main power wire is to protect the power wire - or more
importantly, prevent fire should that wire short out. It has nothing to
do with the current draw of the system.

--
thelizman "I didn't steal the FAQ either"

Before you ask a question, check the FAQs for this newsgroup at
http://www.mobileaudio.com/rac-faq. It contains over a decade and
a half of knowledge.

teamROCS Car Audio Forums http://www.teamrocs.com/caraudio/
teamROCS Car Audio News http://www.teamrocs.com/news/
"It's about the music, stupid"

This post is Copyright (C) 2004. Reproduction of its content anywhere
other than usenet without the express written permission of the author
is forbidden.

On Sat, 13 Mar 2004 21:44:44 GMT, "Richardson, Brian"
wrote:

What would the formula be to calculate main power run fuse size based on
gauge and length?


"thelizman" wrote in message
...
Z. Gluhak wrote:
"Mitzi" wrote in message
om...

What is the proper fuse size to use with my setup. Ive got a
Sony1600w P5 mono amp with an MTX404 thunder connected to its 2nd amp
conectors. My subs off the sony ar 12" kicker CVR's at 4ohms. The
MTX is pushing 4 Orion p6.5's. The setup currently has a 60A fuse that
blows after about 10-15min of use. The fuse was out in before the MTX
was added to the mix so I'm thinking it's not strong enough for the
new setup OR the MTX is causing the blow.

Any suggestion?


THANK YOU!!!

Mitzi



X watts/14.4 volts=fuse size in amps

Not so fast there, hoss. It sounds to me like he's talking about his
main power wire. In that case, the fuse should be appropriate to the
power handling capability of his wire. To know that, we need to know the
gauge and length of the run.

The fuse on the main power wire is to protect the power wire - or more
importantly, prevent fire should that wire short out. It has nothing to
do with the current draw of the system.

--
thelizman "I didn't steal the FAQ either"

Before you ask a question, check the FAQs for this newsgroup at
http://www.mobileaudio.com/rac-faq. It contains over a decade and
a half of knowledge.

teamROCS Car Audio Forums http://www.teamrocs.com/caraudio/
teamROCS Car Audio News http://www.teamrocs.com/news/
"It's about the music, stupid"

This post is Copyright (C) 2004. Reproduction of its content anywhere
other than usenet without the express written permission of the author
is forbidden.


Can't say I know the formula, but I can direct you to a web page with
a ton of info...scrool down until you see the category for wire.
There are several insteresting calculators.

http://www.bcae1.com/

I wouldn't suggest doing this with a meter you care much about. Even
my Fluke is limited to 10A in current mode.

Whoa, settle down there.. Ever heard of an inductive ammeter? They'll easily
measure 200 amps and you just plug it in to your multimeter.