Battery Cable Size?

Discussion in 'Electrical Systems' started by Katoh, Oct 20, 2011.

  1. viking north
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    viking north VINLAND

    RX on my aircraft RCAF Argus Sub Hunters they were tinned copper, miles of the stuff--soldered thousands of multipin connectors. With four 26cyl. engines, loaded to the hilt with fairley lightweight electronics, weight wasn't a problem. She was a flying fuel tanker full of electrons--:D. Although good point I dealth with only heavy military aircraft of the 50's--60's era -- so i would be behind the times on civy and modern gear.--geo.
     
  2. cyclops2
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    cyclops2 Senior Member

    Carefull

    Using Aluminum wire in wet areas is iffy. Especially Saltwater. Corrosion. Can be eating away FASTER 2" back under the the plastic covering. Stays wet a lot longer to speed up the corosion faster.
     
  3. cyclops2
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    cyclops2 Senior Member

    What happened to a simple request ?

    We all give a hoot about the other persons problem.
    Never knew there was so much to learn about a starter cable. :p
     
  4. rxcomposite
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    rxcomposite Senior Member

    Viking,

    Hmm. I did not know that they used that type. My brother and I scrounge these wires from the military airplane graveyard. We get a lot of different wire sizes from a single wiring harness.

    I made a fool of myself once, trying to solder these wires. Tried all sorts of flux and heavy duty soldering iron thinking the shiny coating is tin. :eek:
     
  5. viking north
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    viking north VINLAND

    RX, Possible --this was tinned copper to specifically combat corrosion as often we were down 100ft (times less) off the deck ( sea surface) to extend the detection range of our MAD gear. Aircraft was often covered in salt from sea spray. Another thought and this could apply to the aircraft wiring I have been lucky enough to obtain over the years, maybe it's been aftermarket installed equiptment wiring rather than the standard factory installed main wiring. In our mark 2 we ran a 2.5 million watt aps 20 radar -- so the interconnecting wiring was heavy. I grew up on and near a U.S. SAC/fighter/refuling base so the heavy wiring i collected back in those days might have been the same situation. Recently I obtained some heavy military copper tinned wire from the local scrap yard but i think it was Navy surplus. However if one is luckey to find this it is great wiring.--Geo.
     
  6. Katoh
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    Katoh Senior Member

    These Aircraft wires sound fantastic, but Ill state again in Aus aircraft dismantler's are as rare as rocking horse s**t.
    Would anyone have then any links to US dismantles that they use that would ship to Aus?
    I thought about using multiple cables in parallel, but price still works out the same if not more, then you have the added hassle of using a terminal block at either end or risking trying to join both or 3 cables to one connection, always a little dodgy.
    Thanks for the great Information.
     
  7. viking north
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    viking north VINLAND

    If this were 35 yr. ago after my airforce days I could have shipped you a whole bunch. I worked for some time at De Havilland Air Craft in Toronto and installed the UHF comm. system in the RAAF Buffalo? Caribou? in which alot of electrical wiring and co-ax was re routed or replaced. I'm sure they wouldn't have refused flying some surplus goodies back to a fellow Islander. Check with Government crown assets or enquire around if there is a military equiptment graveyard. Old army tanks, old sub hunting aircraft, old navy breaking yards. Good chance you'll locate something. Be aware as EX has pointed out aircraft wiring could be an alum. alloy. Geo.
     
  8. BertKu
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    BertKu Senior Member

    Maybe you should still consider to look at flexible welding cable, red, green or blue. I am using the red one, i.e. 114 mm2 area. Also consider to seal the plastic end together with the connection with Starbrite to avoid any corrosion.
    Bert
     

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  9. rxcomposite
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    rxcomposite Senior Member

    These aircraft wires should be plentiful. Most aircraft wires used in the airplanes are constantly being upgraded because they fail to pass the FAR 25 rule, so they keep upgrading. There must be plenty of surplus around, not good enough for commercial airplane but good for boat. Generally, aircraft uses the 24 volt system but marine uses the 12 volt system. Thus, a 24V system passes only half the ampere. No problem, just use the correct ampere rating for the wire.

    These wires should be cheap as aluminum is cheaper than copper and aluminum conductivity per weight ratio is better than copper.

    I did use welding cables for starter motors. 12 years now and no problem. I kept it short however. Locating the battery and ground wire as close to the engine as possible.
     
  10. viking north
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    viking north VINLAND

    RX--I like that conductivity per weight -- an expansion of ohms law :D-- Geo.

    P.S. being a man of electrical/electronics, was wondering if you had a HAM set up in operatuion--Setting up my station this fall--after some 35 yrs. since i closed down---
     
  11. Yobarnacle
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    Yobarnacle Senior Member holding true course

    Interesting posts. I'm using weld cable on my electric drive system. I was wondering though, could you use a solid copper bar bus for a common ground for charging? Also, I know in some applications, folks have hammered copper tubing flat for a common bus. Why hammer it flat? Is there a problem with carrying current with a round copper tube? I think I read somewhere that current actually flows on surface of conductors rather than thru core of a solid conductor. Is that true? If copper tubing could be used, could you slip it inside pvc pipe to insulate? lotsa questions, but all related.
     
  12. viking north
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    viking north VINLAND

    Round copper tube can be used but two possible problems- and both involve Conductive contact area: #1 making a good mechanical connection. The tighter you make the fastening the more you collapse the pipe, also you are mating a flat connector to a rounded surface. Less contact area and more potential for movement thru vibration. #2 Again conductive contact area, less area thus higher resistance to current flow resulting in voltage loss or worst a buyild up of heat in that area. Thus the hammering flat to overcome both. Yes you can use a common copper flat bar for all groung connectiuons, it is the recommended practise--No floating grounds. In all cases to greatly reduce corrosion all marine electrics should be tinned conductors'---The surface flow of current is a characteristic of high frequency circuits rather than DC.--- Geo.
     
  13. Yobarnacle
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    Yobarnacle Senior Member holding true course

    THANKS GEO.
    On a long run, if battery and load were 30 ft apart or more, is there enough power savings to justify putting an ocillator in circuit making it ac, then rectifying back to dc near load?
     
  14. Yobarnacle
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    Yobarnacle Senior Member holding true course

    Apologies

    I deleted some recent ill-considered posts you probably saw as emails. My apologies. My previous questions were an installation that was obvious fire hazard and no disconnects.

    I present here a combination positive terminal bus and homemade disconnect idea. There is a negative bus using lead internal ballast.

    The pos bus/disconnect is an assembly of aluminum (could be copper) tube sections isolated with pvc tube sections. In a dry state, there is no circuit. If however, the tube assembly contains an electrolyte, maybe common seawater, all is electrically connected.
    A pressurized air supply and a control valve would enable blowing the water out of the tube through overboard discharges high up in hull. Blowing out the water disconnects all batteries at once. An emergency disconnect.
    I didn't show howto, but refilling tube re-connects batteries.

    Comments please? Never mind official or coast guard viewpoints.
    Is it workable?
     

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  15. viking north
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    viking north VINLAND

    No, on the DC to AC (high vlotage low current run) then AC back to DC -- far too much I squared R (resistive heat losses associated with the equiptment). Better to go one size over on the conductor.
    The problem with using a liquid (fresh or salt water)as a switch is, it will not conduct at the low voltages you are working with. Only electronic or mechanical switches will do the job.
     
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