I want to convert the power cable of.a car fridge to from a cigarette plug to Anderson. Does the writing on the outside of the cable on one side of the cable generally indicate positive or negative?

In my experience, when there is no obvious red or black marking, the white writing indicates positive.

I would use a multimeter though. For the sake of a few dollars you can probe the fridge end and the tip of the cigarette plug and note down which one is positive, and then go from there.

I did the same thing with my Jaycar fridges. Their plug is one of those dual types but I don't trust them and swapped to Anderson plugs or better cigarette plugs depending on where I wanted to use them.

I was once swapping American style plugs for Aussie style plugs and a electronics guy said I needed to get the right wires onto the right plug pin

But I can not understand why it mattered. US plugs can be plugged anyway you like, there is no upside down or right way.... so what difference would it make which wire I placed on which pin (us plugs don't have the earth pins).

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FormulaNova said..
In my experience, when there is no obvious red or black marking, the white writing indicates positive.

I would use a multimeter though. For the sake of a few dollars you can probe the fridge end and the tip of the cigarette plug and note down which one is positive, and then go from there.

I did the same thing with my Jaycar fridges. Their plug is one of those dual types but I don't trust them and swapped to Anderson plugs or better cigarette plugs depending on where I wanted to use them.

Thanks for the info!! Much appreciated. Will get the multis onto it.

Yes normally trace positive.

If you dont have multimeter you could sink exposed cables in the water.
At anode + positive will be bubbling Oxygen
and Hydrogen at negative

to check which one gas is what you could catch some into glass or bottle, and then throw match. definitely you will see and hear the difference between those two. Beisde there will be 2x much hydrogen by volume

Buy a multimeter, a lot cheaper than a fridge. I'm electrician and never play the guessing game. Once the smoke comes out of the wires or fridge, you can't put it back in.

Are these the Anderson plugs you are talking about?

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TonyAbbott said..
I was once swapping American style plugs for Aussie style plugs and a electronics guy said I needed to get the right wires onto the right plug pin

But I can not understand why it mattered. US plugs can be plugged anyway you like, there is no upside down or right way.... so what difference would it make which wire I placed on which pin (us plugs don't have the earth pins).

The US is in the northern hemisphere.

The electrons spin the opposite direction.

So you would need to connect them the opposite way around for Australia.

Except if you plan to use it in Queensland. They all spin crazy directions up there, so it probably doesn't matter.

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shi thouse said..
I want to convert the power cable of.a car fridge to from a cigarette plug to Anderson. Does the writing on the outside of the cable on one side of the cable generally indicate positive or negative?

I am no electrician but I think the white writing on that cable generally indicates it was manufactured by the Yuxuan Electrical Co. Ltd. -v--

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TonyAbbott said..
I was once swapping American style plugs for Aussie style plugs and a electronics guy said I needed to get the right wires onto the right plug pin

But I can not understand why it mattered. US plugs can be plugged anyway you like, there is no upside down or right way.... so what difference would it make which wire I placed on which pin (us plugs don't have the earth pins).

you have AC - DC mixed up. The topic is car fridges run off a battery.
In fully isolated systems it doesn't matter, where the wires go.
But the sparky was right, in the case of aussie AC you need to get active on the correct pin.
Livening up the neutral can have bad consequences.
Neutrals generally get to earth somehow. So the likely hood of an electric shock is high.
If you have earth leakage/residual current protection, that will blow instantly when you plug the thing in.

Macro wins the unecessarily complex aware for the decade.

$5 test light at Supercrap or Ripco would have it diagnosed in seconds....

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Mark _australia said..
Macro wins the unecessarily complex aware for the decade.

$5 test light at Supercrap or Ripco would have it diagnosed in seconds....

Damn, I wish I read this earlier. I had just setup my beakers and everything!

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decrepit said..

TonyAbbott said..
I was once swapping American style plugs for Aussie style plugs and a electronics guy said I needed to get the right wires onto the right plug pin

But I can not understand why it mattered. US plugs can be plugged anyway you like, there is no upside down or right way.... so what difference would it make which wire I placed on which pin (us plugs don't have the earth pins).

you have AC - DC mixed up. The topic is car fridges run off a battery.
In fully isolated systems it doesn't matter, where the wires go.
But the sparky was right, in the case of aussie AC you need to get active on the correct pin.
Livening up the neutral can have bad consequences.
Neutrals generally get to earth somehow. So the likely hood of an electric shock is high.
If you have earth leakage/residual current protection, that will blow instantly when you plug the thing in.

It is an interesting question though. If it was an American appliance, and their plugs can be put in either way so you can never know which one is active, does it matter which one connects to active in Australia? In Aus a device like that would need to be double insulated/isolated I think, or maybe have both active and neutral switched. (<- not advice for anyone BTW).

Obviously this is serious in Aus where the assumptions are that neutral is tied to earth somewhere and that at least the active is switched, but if it's a device that is double insulated or has both switched, it shouldn't matter.

I remember reading stories in 'the serviceman' column in Silicon Chip magazine or similar where people have wired up the nuetral to be switched which has resulted in the devices being deathtraps with a chassis to earth and a live chassis.

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FormulaNova said..>>>It is an interesting question though. If it was an American appliance, and their plugs can be put in either way so you can never know which one is active, does it matter which one connects to active in Australia? In Aus a device like that would need to be double insulated/isolated I think, or maybe have both active and neutral switched. (
Obviously this is serious in Aus where the assumptions are that neutral is tied to earth somewhere and that at least the active is switched, but if it's a device that is double insulated or has both switched, it shouldn't matter.

I remember reading stories in 'the serviceman' column in Silicon Chip magazine or similar where people have wired up the nuetral to be switched which has resulted in the devices being deathtraps with a chassis to earth and a live chassis.

With an appliance that has a 2 pin plug from new, it doesn't matter. To be sold legally in Aus it has to be double insulated.
But we know how people can get mixed up and don't discriminate between different scenarios.
Some would take, "it doesn't matter where the wires go as a blanket rule, youtube said it must be right"!
As you say switching the neutral with swapped over wires, can put full mains on the earth. This will kill people!

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decrepit said..

FormulaNova said..>>>It is an interesting question though. If it was an American appliance, and their plugs can be put in either way so you can never know which one is active, does it matter which one connects to active in Australia? In Aus a device like that would need to be double insulated/isolated I think, or maybe have both active and neutral switched. (
Obviously this is serious in Aus where the assumptions are that neutral is tied to earth somewhere and that at least the active is switched, but if it's a device that is double insulated or has both switched, it shouldn't matter.

I remember reading stories in 'the serviceman' column in Silicon Chip magazine or similar where people have wired up the nuetral to be switched which has resulted in the devices being deathtraps with a chassis to earth and a live chassis.

With an appliance that has a 2 pin plug from new, it doesn't matter. To be sold legally in Aus it has to be double insulated.
But we know how people can get mixed up and don't discriminate between different scenarios.
Some would take, "it doesn't matter where the wires go as a blanket rule, youtube said it must be right"!
As you say switching the neutral with swapped over wires, can put full mains on the earth. This will kill people!

Earth and neutral are never bonded in the appliance. That would be illegal/stupid.

meh.

I learnt everything you need to know about electricky at the skool of life.
red to red
black to black
green/blue/yellow all the same, makes no difference, twist 'em all together.

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Crusoe said..
Once the smoke comes out of the wires or fridge, you can't put it back in.

yes you can

Depends a bit on who made the fridge - you need the correct adaptor to top up the smoke.
If the fridge was made in the USA or Britain you are OK - most U.S. standard threads are near enough as dammit to Whitworth to get by.
If the fridge is Japanese, E.U. [metric] - you will need an adaptor

Lucas is proper olde schoole British from when stuff was supposed to leak to allow excess pressure to escape before damaging internal stuff. [modern materials can handle much higher pressures before degrading and failing] hence the need to make good any leakage.
Anyone who has owned [or parked near] Series Landrovers, or old Triumph motorcycles would understand this principal.

Occasionally - olde schoole tradie learning beats modern tradie head scratching

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FormulaNova said..

decrepit said..

TonyAbbott said..
I was once swapping American style plugs for Aussie style plugs and a electronics guy said I needed to get the right wires onto the right plug pin

But I can not understand why it mattered. US plugs can be plugged anyway you like, there is no upside down or right way.... so what difference would it make which wire I placed on which pin (us plugs don't have the earth pins).

you have AC - DC mixed up. The topic is car fridges run off a battery.
In fully isolated systems it doesn't matter, where the wires go.
But the sparky was right, in the case of aussie AC you need to get active on the correct pin.
Livening up the neutral can have bad consequences.
Neutrals generally get to earth somehow. So the likely hood of an electric shock is high.
If you have earth leakage/residual current protection, that will blow instantly when you plug the thing in.

It is an interesting question though. If it was an American appliance, and their plugs can be put in either way so you can never know which one is active, does it matter which one connects to active in Australia? In Aus a device like that would need to be double insulated/isolated I think, or maybe have both active and neutral switched. (
Obviously this is serious in Aus where the assumptions are that neutral is tied to earth somewhere and that at least the active is switched, but if it's a device that is double insulated or has both switched, it shouldn't matter.

I remember reading stories in 'the serviceman' column in Silicon Chip magazine or similar where people have wired up the nuetral to be switched which has resulted in the devices being deathtraps with a chassis to earth and a live chassis.

Where a lot of people get mixed up is the terminology,

Alternating Current [A.C]
active - live power going in [switch is on the active line]
neutral - live power going out
A common exception is caravans, where both active & neutral are switched [double pole switching]
earth - connects any of the appliance's potentially hazardous metal bits to ground
Generally - A.C. stuff can run ok if active and neutral are swapped - but this can leave the appliance live the entire time [not safe]

Direct Current [D.C.]
positive - power going in
negative - power going out
Generally - if you swap the wires, lights will work - but machinery often runs backwards

There are often protection diodes in electrical stuff [consider these as cheap one way electrical fuzes intended to protect expensive innards] However, you can almost guarantee that something important & expensive will happily lay down it's life to protect it's cheap little brother

Completely off topic but anyways. US has a type A and Type B. Type A is no longer allowed in new constructions. The difference is one prong is slightly thicker so the plug can only go in one way. This makes the appliance safer because the live wire is cut by the switch. Think of a bedside light if the live is switched off and you stick your finger in the bulb socket in the old plug you have a 50/50 chance of electrocution because live may be on either side of the switch. New plug style makes the live run to the switch 1st which stops live going to the bulb socket so no burnt fingers.