AC cord polarity?? Does it matter???????


I've just noticed that from experimenting with preterminated factory builty cords that not all companies use the same polarities. Even with two stock cords, one from USA made in China and one from China made in China for USA the polarity of the cords are reversed. All my Synergistic cords are one way, my Electraglide is the other way and other cords from different manufacturers are different. The poles are reveresed from one cord to the next. Now I'm really confused to the polarisation issue as if different companies use one polarity and other companies use the reversepolarites, then it's a guess wether or not one system is in the right polarity or if just certain components are properly polaroized. It appears that in the US made cords I've noticed both direct and reverse polarity in cords. The Asian made cords are different depending on company as well. Does this then mean that polarity has no issue and it doesn't matter? Is there no right or wrong way to polarize a components ac? The cords in my system are giving half my components one direction of ac polarisation and the other half are in reverse.Perhaps it doesn't matter? I'm confused again!!!!
128x128mitchb
>>"Of course if you decide to use a balanced power unit, all this is of no concern."<<
[Nsgarch]
>>>>>

Maybe, True if all the audio equipment connected by ics is pluged into the same balanced power unit.
==========

Nsgarch, What is your thoughts of feeding a balanced power unit from 120V? Jmho, I believe there would be better isolation if a balanced power unit was feed by 240 volt.

Here is some reading material. Make note of how the utility companies bond the high voltage neutral and all the secondary neutrals together at every utility transformer.
This can't be good for AC noise....
http://www.mikeholt.com/documents/strayvoltage/pdf/DangersofStrayVoltageandCurrent.pdf
Jmo it appears to me the only way to get total AC isolation is with an isolation transformer fed from 240 volt.
Jim
Post removed 
Jea, a 240V line is inherently "balanced". Its ground and neutral are the same (center) conductor, with a potential of +120v on one side and -120V on the other (which reverses every 60 sec. of course.) BTW, I don't believe European 240V power is configured this way (at the outlet), but somebody correct me if this is wrong.

Now to get balanced 120V is a whole 'nuther matter. First you get a great big toroidal transformer and feed it 120V +/_ into one tap and zero volts (neutral) into the other. In a second, identical winding, you take the power out at 60V +/_ tap and 60V -/+ tap and feed one to each blade of the AC plug. To keep the drama queens at U/L happy, you create an artificial ground/neutral for the center ground pin of the plug/receptacle. This is done through some kind of circuitry which U/L is willing to certify provides shock protection ;~)) but it's not an "earth" ground.

If your equipment circuit designer or assembler has been less than attentive as you postulate, then balanced power will save his/her ass because both primary leads are being fed equal (60V) voltage in a "push-pull" arrangement around (or across) an "imaginary" ground (rather than the normal zero volts in one lead and plus-or-minus 120V in the other.) So in the balanced-power-fed component, circuit polarity relative to ground disappears along with any polarity mismatches in the wiring.
Post removed 
Mitchb:

I don't know why your power cords would be reversed, but to meet current NEC codes, they have to be polarized the the right way. For your basic 115 V three prong cable, the big one is earth, the wide one is neutral, and the smallest one is the hot or line.

Now that being said, there are some older cords which are not polarized correctly, as they were made long before polarity for line cords was written into the NEC. The thing is, I am pretty sure by the time the IEC connector came along, polarity had been in the code for a while. I do believe this was the reason the IEC connector was adopted. I am writing this from memory; I don't have a history of NEC at my disposal.

I suggest you pitch the incorrect polarity power cords. If you are in doubt about which one is correct, go to your local hardware store and buy a Belden cord for about 7 bucks or so. This will be correct; compare everything to this and toss the ones which are polarized opposite.

You can check your wall outlets in your house/apt easily enough: when you are the hardware store, pick up a line polarity tester for around 5 dollars or so. On this are a series of LEDs which light up depending on what is wrong. You can get expensive and blow up to 10 bucks on one if you want to also check the GFI outlets in your kitchen or bathroom, but you won't need GFI testing for your stereo stuff.

By the way, if one of the cables you find is polarized backwards and it has a UL sticker on it, please call your local UL office, they are in the phone book. I am SURE they will be MOST interested!