Aluminum Wire: White = Negaive?

[mitiempo]

Originally Posted by Gone2long

Gang,

Have some aluminum wire on my boat.

How did you decide it is aluminum?

[Greenhand]

I found a case where the green wire was positive. Luckily, I didn't fry anything in the process of finding that out.

[Marqus]

Originally Posted by klmmicro

I found my AC power cabling set up the way I see it in normal household systems, Black/load - White/common - Green/ground.

Wow, that is a surprise. For older AC wiring (not brown/blue), I have mostly seen:
RED = Active and
BLACK = Neutral (with Green being Earth).

If there are some places where Black turns out to be the Active wire, that could be a bit of a shock.

[mitiempo]

Black (hot), white (neutral), and green (ground) are the normal AC color codes in North America - where klmmicro is located.

[Marqus]

Gee thanks for quick reply. Too close for comfort if I happen to fiddle with AC wiring on a US-built boat - for Live/Neutral the Brits used to use Red/Black while the US uses Black/White. Better not forget that one.

[Wotname]

Originally Posted by Marqus

Gee thanks for quick reply. Too close for comfort if I happen to fiddle with AC wiring on a US-built boat - for Live/Neutral the Brits used to use Red/Black while the US uses Black/White. Better not forget that one.

Yeah but it's only 110 V in that far off land, hardly worth worrying about the colours

[Marqus]

Originally Posted by Wotname

Yeah but it's only 110 V in that far off land, hardly worth worrying about the colours

Ah, relief - so I can just use the wet tongue test to find the hot wire then ..

[mitiempo]

Originally Posted by Marqus

Ah, relief - so I can just use the wet tongue test to find the hot wire then ..

Yes, once.

[Gone2long]

Originally Posted by skipmac

Is this DC or AC?

Solid or stranded?

Are you sure it's aluminum and not tinned copper?

Sent from my SCH-I545 using Cruisers Sailing Forum mobile app

System is DC, 12v - stranded. Assume it's aluminum from rather large size.

G2L

[Gone2long]

Originally Posted by Wrong

Whoa! If it's on a boat - unless you did the original wiring - never, never assume the wires conform to code.

In my experience red OR white wire is normally used on positive runs. Black is typically used for ground.

Hi again,

I tested the wire with an Ohm meter (spelling?) and when I connected the red wire to the red (positive) meter probe and the white wire to the black (negative) meter probe, I got a reading of 12 or so volts.

When I switched them I got no reading, so I assume that this test "proves" that the white is negative.

Thanks to all,

G2L

[Gone2long]

Originally Posted by azsailor12

Aluminum wire should not be used on a boat. If it was mine, I would replace it with marine grade tinned copper. If your meter shows it to be negative, then it likely is. Can you follow it back to the panel to confirm?

Thanks for the advice. I did not have a good Ohm meter handy when I wrote the original blog, but I purchased one soon afterwards and the results are noted in my reply above. Sorry for taking so long getting back to everybody.

Regards,

G2L

[Gone2long]

Originally Posted by Garrettw

I would think aluminum wire is fairly uncommon on a boat; it is the least noble of all commonly used conductor materials. You may be mistaking tinned copper.

Yes, that could be. Do not really know how to tell the difference.

The original boat owner is 9,000 miles away, and got nobody to ask.

Thanks for your help,

G2L

[jeepbluetj]

Originally Posted by Gone2long

Hi again,

I tested the wire with an Ohm meter (spelling?) and when I connected the red wire to the red (positive) meter probe and the white wire to the black (negative) meter probe, I got a reading of 12 or so volts.

When I switched them I got no reading, so I assume that this test "proves" that the white is negative.

Thanks to all,

G2L

Nope. That proves absolutely nothing, as your report of what the voltmeter is doing doesn't make all that much sense. (I assume you're measuring DC volts, not ohms)

Even with an analog meter, one way will be +12 volts (red on +, blk on -) and the other way will move the meter 'negative' -- i.e. 'left' of 0.

With a DMM (digital multimeter) reversing the leads would show -12v as opposed to 12v. If it's nothing the 'other' way, something is wierd, or you have the worlds strangest meter.

[skipmac]

Originally Posted by Gone2long

Yes, that could be. Do not really know how to tell the difference.

The original boat owner is 9,000 miles away, and got nobody to ask.

Thanks for your help,

G2L

If the strands of the wire are very fine, like a little larger than a hair then it is almost certainly copper. It may exist but I am not aware of stranded aluminum wire that is fine stranded since the metal would be too weak to hold up.

Proper wire will usually be marked on the insulation with the gauge and if it's certified UL, etc.

If you have enough slack on the end of the wire scrape some of the strands with the edge of a blade and look at the wire closely to see if it looks yellowish inside. You might have to use a magnifying glass as shiny copper might be hard to tell.

I agree with the meter question. If you are using a digital meter it would show +12 one way and -12 the other when you reverse the leads. If it is an analog meter (has a needle) then it won't show -12 but you can see the needle bounce slightly to the left when you connect the leads backwards.

[skipmac]

By the way, what does this wire go to and where does it come from?