IEC type power cord not correctly labeled

[Buckethead]

TL;DR Summary

The L and N labels on an IEC power cord appear to be reversed

I'm confused. I have in my hand a 120VAC power cord with a standard 3 prong US plug on one end and a common IEC connector on the other (the type that plugs into a desktop computer for example). The IEC female end is labeld L, N and Earth. Hoever if I measure the voltage between the L and Earth I get essentially 0 and when I measure between N and Earth I get 120VAC. In addition I did a continuity check between the N and the male end and it is connected to what would be the thin blade going into the wall outlet, i.e. the hot blade. In all online documentation, the labeling on the cable is correct. My test says it's not. Someone please help. Going nuts!

 

[berkeman]

Yikes! So the cable female end has L and N swapped compared to the male receptacle that it goes into?

https://www.electronics2000.co.uk/images/data/iecdiag.png

https://cdn.sparkfun.com/assets/9/6/1/7/0/51141f68ce395f7d7e00000c.jpg

https://media.fs.com/images/community/wp-content/uploads/2017/08/Nema-5-15-standard.jpg

 

[Buckethead]

No, I meant that the female end of the cable appears to be swapped to its own male end. In other words, the N lable on the female end is connected to the blade on the male end that plugs into the thin slot (hot slot) on a wall outlet. All cables of this type are like this. That is why I'm confused. Do the test yourself. I'm not making this up.

 

[Baluncore]

We don't use the same outlet/plug system. Perhaps a picture of your wall outlet (female) showing PE, N and the 120V active would help.

 

[berkeman]

We don't use the same outlet/plug system. Perhaps a picture of your wall outlet (female) showing PE, N and the 120V active would help.

I added a photo of that to my post above just now. I also went and got a powercord and receptacle to beep out...

 

[berkeman]

My hot lead ("Line") beeps just fine from the male plug end through the IEC connector end...

No, I meant that the female end of the cable appears to be swapped to its own male end. In other words, the N lable on the female end is connected to the blade on the male end that plugs into the thin slot (hot slot) on a wall outlet. All cables of this type are like this. That is why I'm confused. Do the test yourself. I'm not making this up.

All what cables?

 

[Baluncore]

I added a photo of that to my post above just now.

In Australia we use a 240V crows foot with the PE down, I believe it is the same as used in China.

Unlike the N. American 120 Vac system, we have 240 Vac active on top left, and N on top right. Maybe the Chinese have swapped the convention to their own?

 

[Buckethead]

Thanks for posting the US outlet photo. Yes, that's what I'm dealing with. The hot (thin) slot on the wall outlet connected to the IEC connector Female end that is labeled N.

 

[berkeman]

Thanks for posting the US outlet photo. Yes, that's what I'm dealing with. The hot (thin) slot on the wall outlet connected to the IEC connector Female end that is labeled N.

Does your power cable match the labeling in the photo that I posted of the female IEC end? In that case it would be correct. If not, then the labeling is wrong, but the cable is wired correctly?

 

[Buckethead]

Oh Wow, I just dug up several similar cables (made by different vendors as they are slightly different builds) and they ohm out correctly with the L connected to the hot. Amazing! Different cables are indeed wired differently. I would have never thought these cables could be wired differently. How is that possible?

 

[Buckethead]

Does your power cable match the labeling in the photo that I posted of the female IEC end? In that case it would be correct. If not, then the labeling is wrong, but the cable is wired correctly?

Yes, the "bad" power cable does match your photo with the L and N embossed on the connector just like your photo. And on this one cable the N is connected to the hot side of the other end (thin blade). See my last post, I dug up some additional cables and they are wired correctly, I was testing on an actual defective cable!

 

[berkeman]

If just the labeling is wrong, the cable is still good. You just plug it into standard IEC receptacles anyway, right? If the labeling is wrong, that might confuse somebody who is trying to learn about electrical wiring, but it will not be an issue in the standard use of the cables, right?

 

[Buckethead]

No the cable is not good. The label conforms to the correct wiring, but is not what the cable is doing. The L label is connected to ground even though it is identical to your photo.

 

[Buckethead]

Thank you all for your help. I was truly going out of my mind and checked like 10 times that I must have been doing something wrong, but nope, out of the 4 random cables I found around my house, 3 were wired correctly and the one I happened to be testing on was wired in reverse. It's an ordinary looking cable, just like the others and it's scary to think there are probably millions of these bad cables in circulation. Wow. Epiphany, always check your cables before using. That one cable is cut in half and now in the garbage!

 

[berkeman]

The L label is connected to ground even though it is identical to your photo.

BTW, what motivated you to check the pinout of that power cable? If Line was cross-wired to GND, were you getting shocked when you touched the device that it was powering?

 

[Buckethead]

Good question. No, i was building a prototype electronics project with an IEC connector and just wanted to get the hot wired to the correct side of the connector. When I checked the internet then checked the power to the IEC connector, they didn't match. No shock thank goodness.

 

[anorlunda]

Sigh. Yet another worrisome source of vulnerabilities associated with our supply chain. Not as dramatic as the solar winds hack, but still cause for concern.

Surely consumers can't be expected to check things they buy like cables and cords. Surely government does not have the resources to inspect everything imported. Nor does Amazon have the resources to inspect and check everything sold on their market.

I don't see any general answers to these general problems.

 

[Buckethead]

Indeed! I don't know where this cable came from, probably just packed with a consumer product I had bought at some time. I have so many of these cables lying around. I happened to pick just the wrong one to do my testing. But yes, the cable was the LAST thing I would have suspected. I was doubting my sanity before I doubted the cable! Who would have guessed!