OK boys,

look sorry to monopolise the topics but you guys should be cranking up the SPL questions / info as well (I gotta tell you though the real motivation is to try and beat those SQ heads with the amount of topics we got in SPL).

this one is on C/B's, Purps told me this one and I didnt really believe him at the time but he was right on with the observation that once a breaker has been tripped it will then keep tripping at a lower and lower current draw.

So although it looks like a good option and an easy circuit isolation switch once they pop, they can't stop (sorry about that).

As I understand it though a C/B does have a lower resistance than a comparable fuse so the pro's and cons need to be wieghed up.

------------------
TEAM DD "In the Lanes, takin names"
No more Amps, got scared of all the competition and ran away!!
SPL King Wagga 2002/SAS 2002
Broken window/hurt hand Wagga 2002
Best 158.4db from 2x DD9515's on TERMPRO (SAS 2002)

please tell me what one of these things are and how they work. i have heard of them, but i haven't actually seen one used. how would it differ to my jaycar anl fuse thing i'm using now?

------------------
2002 Holden Astra
HU: Blaupunkt Miami Beach
Front Stage: Orion XTR 6.2
Front Amp: PPI 2360 2x90
Subs: 2 x Audiobahn 1200Q
Sub Amp: JBL 1200.1
Dead Last at Drag Combat 2-3 Woofer class
Winner at BAS 161-260sq inch.

same as a fuse except rather than blowing the fuse and having to replace it the breaker just flicks a switch, which you can then switch back, no need for a replacement fuse etc.

------------------
HOLDEN--Pioneer
Car:VN Commodore
Head Unit:Pioneer DEH - P3150 with 12 Disc Stacker
Fronts:Crappy 6" Kenwoods in VR Door Pods.
Rear:Pioneer TS-A6955 6x9's in MDF parcel shelf.
Amp & Sub:On the way once i can afford them!!!
My Web Page
"He had a lot of nothing to say, we'll miss him"- Eulogy - Tool

some use a bi-metallic strip(think thats wat they are called) as we all know diffrent metals heat up at diffrent speeds so u have a strip of metal with two diffrent metals. (i think they use copper and somthign else) as the copper heats up quicker(eg with more current) it causes the strip to bend and break the circuit. so when it cools down it will kick back in or the switch is thrown. please correct me on any wrong bits as I never really listerned in physics.

------------------

Team Tycoon - Dollars n dB's
a little Beyond Audio and a little Power = BUUURRRRP

how much do they cost? can you set them to kill the circuit and different amounts of current?

------------------
2002 Holden Astra
HU: Blaupunkt Miami Beach
Front Stage: Orion XTR 6.2
Front Amp: PPI 2360 2x90
Subs: 2 x Audiobahn 1200Q
Sub Amp: JBL 1200.1
Dead Last at Drag Combat 2-3 Woofer class
Winner at BAS 161-260sq inch.

http://www.howstuffworks.com/circuit-breaker.htm

smaller ones r usally Bimetalic and bigger ones use electromaget(thanks kid)

u can usally get a CB for any figure

------------------

Team Tycoon - Dollars n dB's
a little Beyond Audio and a little Power = BUUURRRRP

i have Stinger ANL fuses in my car, tho in 3 of the 4 last install's ive done ive used Stinger c/b's; their sticker price is usually ~$130-140, but can get them for around $100-110 and in most ratings up to 150A.
never ever had a problem with any of them, however....i put a 85A (or maybe 90A...forget now) Aerpro c/b in my mates car, biggest mistake ive ever made, constantly trips when the cars being driven, the wiring has been checked, checked and re-checked and no problems there. changed it to a fuse temporarily (yep same rating) and she was sweet as pie, he is now forking out for a Stinger replacement
ummmmm....so moral of my little story? not only are the aerpro ones like half the price (yey), theyre made of cheapo plastic, use cheapo nuts with washers that fall apart when you tighten them, the clear covers necessary to stop shorting the terminals are extra and ontop of that...they look fugly (yeh real important in an spl car )
so yeh, from experience i can safely say to not skimp when it comes to fuses and cb's quality wise

------------------

Pioneer,Soundstream,Total Recoil,Rockford Fosgate,Alpine,Stinger,Dynamat and Odyssey
...Who need's a back seat anyway?

i've also heard that you need a higher rated CB than if you used a fuse instead.
(only applies if you don't play tones)

Reasoning:

fuse blows after holding it's rated current for 60sec, sometimes 120sec, depends on fuse
this sounds bad at first, but if you draw 50% more than it's rating, it'll blow REAL quick

a CB blows once you exceed it's rating, in say 5 100th's of a second.

so if you're playing music, and a big bass hit comes, and darws 91A through you're 90A circuit breaker, BAM, CB trips, no bass.

but with a fuse, it will tolerate that peak. you may get away with a 70A fuse

of course as soon as you play tones, the "peak" current draw becomes a constant current draw, and the fuse will blow.


just something to be aware of, if you have a 70A fuse, and change to a CB, you may need to recalculate your current draw to make sure you buy the right rating.

------------------
'96 Mirage, currently resembling a tin can
uninstalled: Rockford RFX9300, Focal 165W3's Vrx 2.150 & 1.500
Power by: HERTZ audison OPTIMA StingerAerpro
TEAM AUDISON

Mr_bob, I guess it depends on how they are rated, I would have assumed that circuit breakers would be rated the same way as a fuse?? but obviously not

------------------
- A proud member of Team Gates - A proud supporter of the CAA SPL project

[Edited 1 time by Bassaholic on 26 September 2002 at 19:35]

sorta, but the behave differently, a CB won't trip after 30sec of having 1A over it's rated current, it'll either trip, or not trip.
a fuse will slowly melt, so the more current it gets, over it's rated figure, the faster it will blow, but they are never meant to blow under their rated figure.
i guess even with tones you could pull 100A through a 90A fuse for up to 1.5sec without a trouble,
no chance a CB would allow this.

------------------
'96 Mirage, currently resembling a tin can
uninstalled: Rockford RFX9300, Focal 165W3's Vrx 2.150 & 1.500
Power by: HERTZ audison OPTIMA StingerAerpro
TEAM AUDISON

quote:

---

Originally posted by Mr_Bob:

a CB blows once you exceed it's rating, in say 5 100th's of a second.
91A through you're 90A circuit breaker, BAM, CB trips, no bass.

---

well, kinda

CB have an exponentioal (sp) rize, a cb would probaly hold 91A in a 90a breaker for an hour but it would trip. 100a in a 90a breaker a few mins maybe.

cb are supposed to handle spikes in current, becase, for example, alot of motors and high power lights have a large starting current.

this applies for 240V AC, but i am sure the principles are the same.

------------------
MitsubishiMagnaTR'92

12W3vsKicker all smiles dis end-o-town

... really?
that's not how i understood it to work

is the rate of a fuse linear, and a CB exponential?
that could explain the differences as i unerstand them

------------------
'96 Mirage, currently resembling a tin can
uninstalled: Rockford RFX9300, Focal 165W3's Vrx 2.150 & 1.500
Power by: HERTZ audison OPTIMA StingerAerpro
TEAM AUDISON

hi,
i have a fusion 140amp circuit breaker at the moment. can't complaing because i have never blown it. It was only about $60 as well.

For anyone that is running some really high power systems like 2000wrms or up, could you tell us what you use? C/B or fuses.

thanks in advance

------------------

1988 toyota soarer


playa:Clarion 7675z
tiss tiss:planet audio 6.5'" splits
boos boos:JL 15W0
louder maker:clarion vnet 4150

quote from jaycar cat:

70A DC
Will trip within 1 minute at 90A load. Will trip within a few milliseconds under short circuit conditions.

100A DC
Also works 12/24V. Will trip at 110A or immediately under short circuit conditions

not too sure about the fuses bob, i'll get back to you.

although, i am using a 40A fuse in my engine bay feeding my zr360 and 4chan boss 200MAX watts (ummm... 10 wrms ) and it hasnt blown yet, was kinda gonna leave it there to see if (when) it will blow.


------------------
MitsubishiMagnaTR'92

12W3vsKicker all smiles dis end-o-town