Author Topic: Main Switch  (Read 2489 times)

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chrishallett83

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Re: Main Switch
« Reply #15 on: October 30, 2009, 03:44:58 AM »
I bet but since a busa only makes approx. 33 amps max it might be a bit overkill both in cost and maybe size.

Alternator might only put out that much, but what about starter motor draw?

Online fabr

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Re: Main Switch
« Reply #16 on: October 30, 2009, 06:03:41 AM »
Starter motor draw wouldn't matter in a battery isolator used for the charging circuit. At least that is my understanding. I could be very wrong about that though. At any rate it is a moot point for us as I doubt anyone here is going a dual battery route due to the extra weight and complexity.
"There can be no divided allegiance here.  Any man who says he is an American,
but something else also, isn't an American at all.  We have room for but one
flag, the American flag... We have room for but one language here, and that is
the English language... and we have room for but one sole loyalty and that is a
loyalty to the American people."
Theodore Roosevelt 1907

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"I fear the day that technology will surpass our human interaction. The world will have a generation of idiots" Albert Einstein  (IT'S OFFICIAL THAT DAY IS HERE NOW!)

Jet

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Re: Main Switch
« Reply #17 on: October 30, 2009, 05:46:30 PM »
Clearly Us Aussie are right, you guys still work in imperial! P= V x R came AFTER that age  ;D

I was going to come over that way for a scholarship, Until I remembered you guys are imperial, there's no chance Im studying engineering in imperial!

On the subject of main switch's, have any of you found any good quality switch's that dont play up in the dirt?

Online fabr

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Re: Main Switch
« Reply #18 on: October 30, 2009, 07:48:38 PM »
I found some real cheapies ,I don't remember where, but they are open construction or unshielded that will handle 50 amps continuous plastic and brass-never had a problem. Mud/dirt/sand just dries up and falls free. Only cost like 4 bucks. They might have been HF junk for all I remember but they work.Red and black plastic they are.
"There can be no divided allegiance here.  Any man who says he is an American,
but something else also, isn't an American at all.  We have room for but one
flag, the American flag... We have room for but one language here, and that is
the English language... and we have room for but one sole loyalty and that is a
loyalty to the American people."
Theodore Roosevelt 1907

-----------------------------------------------------------
"I fear the day that technology will surpass our human interaction. The world will have a generation of idiots" Albert Einstein  (IT'S OFFICIAL THAT DAY IS HERE NOW!)

chrishallett83

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Re: Main Switch
« Reply #19 on: October 31, 2009, 12:07:44 AM »
Starter motor draw wouldn't matter in a battery isolator used for the charging circuit. At least that is my understanding. I could be very wrong about that though. At any rate it is a moot point for us as I doubt anyone here is going a dual battery route due to the extra weight and complexity.

Isolators I'm talking about have both battery leads going into them. What used to bolt onto the battery terminals now bolts onto the output terminals of the isolator.

Dunno about a dual battery setup, I just don't want to see you fit up an isolator that could be too small and weld it up solid when you hit the starter.  ;D

The alternator may only charge at 33 amps, for which a 50 amp isolator would be fine, but how much is being drawn through the battery leads at startup?

Online fabr

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Re: Main Switch
« Reply #20 on: October 31, 2009, 06:42:08 AM »
Damn sure not a thousand. Max could only be CCA of the battery being used.
"There can be no divided allegiance here.  Any man who says he is an American,
but something else also, isn't an American at all.  We have room for but one
flag, the American flag... We have room for but one language here, and that is
the English language... and we have room for but one sole loyalty and that is a
loyalty to the American people."
Theodore Roosevelt 1907

-----------------------------------------------------------
"I fear the day that technology will surpass our human interaction. The world will have a generation of idiots" Albert Einstein  (IT'S OFFICIAL THAT DAY IS HERE NOW!)

2088bob

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Re: Main Switch
« Reply #21 on: February 21, 2011, 06:20:52 AM »
i dont know if you guys remember as i have not read the entire post either but vw did switch grounds ccts in their cars OEM

Offline komelika

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Re: Main Switch
« Reply #22 on: January 09, 2013, 06:24:29 AM »
It may well do so but i admit i don't understand that. You guys need to do some splaining as I was not taught that but I may have had a mistaken teacher. Enlighten me. I remember this coming up before but I didn't understand it then either.

Join the Navy! They take the first two weeks of any electrical school and reprogram you to understand that electricity flows from negative to positive.  rofl
If you remain calm while everything around you is complete chaos... then you probably haven't fully understood the situation!

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Re: Main Switch
« Reply #23 on: January 09, 2013, 06:47:22 AM »
I just got ripped for being an idiot over at GD for having the gall to say that. LOL!!!! Well,actually I said that a negative side main kill switch is preferable to a positive side main kill. I admit that that runs contrary to what we generally accept here in the US.
"There can be no divided allegiance here.  Any man who says he is an American,
but something else also, isn't an American at all.  We have room for but one
flag, the American flag... We have room for but one language here, and that is
the English language... and we have room for but one sole loyalty and that is a
loyalty to the American people."
Theodore Roosevelt 1907

-----------------------------------------------------------
"I fear the day that technology will surpass our human interaction. The world will have a generation of idiots" Albert Einstein  (IT'S OFFICIAL THAT DAY IS HERE NOW!)

Offline komelika

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Re: Main Switch
« Reply #24 on: January 09, 2013, 10:13:37 AM »
I hear you. Most of the guys in my class had atleast a basic understanding of electricity so that little nugget of info made us laugh since we assummed the instructor was messing with our heads.

I don't know wether it actually changes anything unless you're designing circuit boards or something, but it doesn't necessarily change troubleshooting or running wires that I know of. Unfortunately, working in my job rarely requires troubleshooting circuits so I have lost a lot of what I once knew over the last 15 years, but I can't see any reason cutting off neg. makes a bit of difference.

I drink too much beer to retain info that I don't use.  dd:
If you remain calm while everything around you is complete chaos... then you probably haven't fully understood the situation!

http://sandjunky710.blogspot.com/

Online fabr

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Re: Main Switch
« Reply #25 on: January 09, 2013, 10:42:49 AM »
Using - as the main kill completely isolates the battery. Another thing to consider ,especially if you are running in excess of 50 amps continuously from the battery ,is that most of the kill switches we use are rated at 50 amps continuous. If using the - for the main kill there is fewer amps drawn through the switch since some of those amps are "consumed" by the device being run such as a fan.
"There can be no divided allegiance here.  Any man who says he is an American,
but something else also, isn't an American at all.  We have room for but one
flag, the American flag... We have room for but one language here, and that is
the English language... and we have room for but one sole loyalty and that is a
loyalty to the American people."
Theodore Roosevelt 1907

-----------------------------------------------------------
"I fear the day that technology will surpass our human interaction. The world will have a generation of idiots" Albert Einstein  (IT'S OFFICIAL THAT DAY IS HERE NOW!)

Online fabr

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Re: Main Switch
« Reply #26 on: January 09, 2013, 11:00:15 AM »
Consider starter motor current draw across the kill switch when positive is used as the kill circuit also.While cranking there will be anywhere from 100 or so to upwards of 800 amps drawn through the kill switch depending on engine/compression/cid etc..  If I recall correctly most are rated approx 250 amps intermittent.
"There can be no divided allegiance here.  Any man who says he is an American,
but something else also, isn't an American at all.  We have room for but one
flag, the American flag... We have room for but one language here, and that is
the English language... and we have room for but one sole loyalty and that is a
loyalty to the American people."
Theodore Roosevelt 1907

-----------------------------------------------------------
"I fear the day that technology will surpass our human interaction. The world will have a generation of idiots" Albert Einstein  (IT'S OFFICIAL THAT DAY IS HERE NOW!)