vanifest
Boise, Idaho
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Joined: 02/11/2010
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I'm sorry for taking over the B forum, folks. Thank you for tolerating all my questions. Your responses have been a great help.
Here is another part of the installation. What is the TINY wire going from the isolator to the 100 amp fuse? There is a BIG wire From the 100 amp fuse to the starting battery. (the 100 amp fuse was already in there from a hydraulic wheelchair lift that was removed from the van).
Is 80 amps enough? This is a 2000 Dodge Ram Van, V8 engine.
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enblethen
Moses Lake, WA
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Joined: 01/05/2005
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the wire from the fuse to the isolator sure does look large enough for 80 amps. What size is the wire?
80 amps should be good for charging.
Bud
USAF Retired
Suzuki XL7 pushing Pace Arrow
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skipnchar
Topeka or somewhere else
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Joined: 12/17/2003
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Just curious, are you building an RV?
2011 F-150 HD Ecoboost 3.5 V6. 2550 payload, 17,100 GCVWR -
2004 F-150 HD (Traded after 80,000 towing miles)
2007 Rockwood 8314SS 34' travel trailer
US Govt survey shows three out of four people make up 75% of the total population
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vanifest
Boise, Idaho
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Thanks for taking a look, it sounds like it is ok after all. I went and looked at the wires and they didn't have a size printed on them.
Yes, I am sort of building an rv. It won't have water or a toilet, though. The sleeping platform was already built in there when I bought it and I'm mounting some rubbermaid drawers for storage. It's a work in progress.
I'll post some pictures when it's all done!
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landyacht318
Near a large body of water
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Joined: 07/11/2007
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To me, judging by the yellow o-ring crimp connectors, that suspect wire is 12 awg wire.
According to this site:
http://www.powerstream.com/Wire_Size.htm
12 awg wire will pass only 41 amps.
So that 100 amp fuse is not protecting that 12 awg wire, and it is limiting the alternator current to the isolator to 41 amps. Your 200 a/h AGM battery, when depleted, can ask for way more than 41 amps. If your alternator and stock charging system can pass that much current for any length of time is certainly debatable.
To maximise alternator recharging, I would upgrade that wire to 4 awg, like the rest of the wiring leading from the starting battery to the isolator. The only issue should be bending a 12 inch length to fit. You can find that at any auto parts store.
Your 'professional' would have installed it, but had forgotten about the already existent fuse, and didn't want to make another run to the store just for another length of wire.
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loving retirement
SF Bay Area
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Joined: 06/30/2006
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landyacht318 wrote:To me, judging by the yellow o-ring crimp connectors, that suspect wire is 12 awg wire.
According to this site:
http://www.powerstream.com/Wire_Size.htm
12 awg wire will pass only 41 amps.
I believe by rating #12 AWG to pass 41 amps is over rating the capacity of the wire. The wire gauge table listed above is designed for electronic chassis wiring, not auto or residential. The quoted table assumes the wire is in open air, that the wire is not bundled and that no allowance has been make for any higher ambient temperatures like under the hood with a hard working V8 engine.
The National Electric Code rates #12 AWG ("ampacity at 75 degree C conductor temperature 30 degree C ambient") as 20 amps (one to three conductors). When using a single conductor in free air, the rating increases only to 25 amps. This is why in the US when #12 gauge wiring is used in a residential branch circuit, the National Electric Code requires the branch circuit be limited with a 20 amp circuit breaker.
In my opinion, that wire should be upgraded.
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wsfurrie
Florida
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Joined: 09/14/2007
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It looks to me as though you have 2 fuse's in series. A 100 amp fuse and a piece of wire that will burn out first. I am assuming that the fuse was used to protect the isolator circuit although I have never seen one used like that.
Wayne
Wayne
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