I know the correct answer is to always run a separate ground wire to properly upgrade a 10-30 receptacle to a 14-30 receptacle. However I noticed amazon sells many of these adapters which instruct you to plug in the separate ground wire to an existing ground slot on a normal 5-15 outlet. I suppose in theory this all checks out other than looking really odd. And I don't think they could get away with selling these if they were illegal. But can you think of a reason this would not be up to code? What about the ground wire having a smaller gauge on the 5-15 outlet compared to a normal 14-50 outlet?

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    Have you found any that have a UL, ETL, or CSA listing/label. I bet none have those labels and those labels say if they are legal/safe or not. Amazon gets a lot of stuff from China that they should not sell.
    – crip659
    Commented Jul 29, 2023 at 14:56
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    "What about the ground wire having a smaller gauge on the 5-15 outlet compared to a normal 14-50 outlet?" Yes, this is exactly the problem. I'm pretty sure a 30A dryer outlet needs more than a 14 ga ground from a 15A outlet.
    – Armand
    Commented Jul 29, 2023 at 16:53
  • If you have a valid ground wire for a 30A or larger circuit you can get to by running a ground wire of that size (10 AWG copper or 8 AWG aluminum), you could safely, legally, and to code bring ground to a (properly wired, not a given) NEMA 10 so you could replace it with a NEMA 14. Of course, quite often if you look inside the NEMA-10 enclosure you'll find a disused or improperly bonded to neutral grounding wire already present, because the point where they finally outlawed new installations of NEMA-10 (1996 code cycle) was long after /3 with ground cables were standard.
    – Ecnerwal
    Commented Jul 29, 2023 at 17:24
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    "And I don't think they could get away with selling these if they were illegal." – Think again! One thing that's important to note is that technically, Amazon isn't selling most of the stuff listed on Amazon.com; most of the listings have a little note saying something like "sold by Asdfhjkl." If you buy one of those items and it ends up killing someone, and you sue Amazon for it, they'll say, "oh, we didn't sell you that item, Asdfhjkl did." Commented Jul 30, 2023 at 12:16
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    Interesting point. Makes you really think twice about the stuff you buy off amazon.
    – Fred
    Commented Jul 30, 2023 at 13:53

2 Answers 2


Don't buy electrical gear via mail order

Absolutely not. Dangerous rubbish. You can tell from the obviously Photoshopped spiral on the ground lead, and the use of a "banana plug" on the end of the ground lead ROFLMAO. This is a "cheap Cheese junk" found on a scummy mail-order site such as eBay. (and yes, I know you used Amazon; the problem there is Amazon Marketplace, which is is 3rd party listings exactly like eBay and their results are blended in with regular results. Amazon bundles their "Amazon Fulfillment" warehousing and shipping service for the seller, which is why it ships with Prime, so it feels like an Amazon item. The text which mentions it being a 3rd party seller is right under the "Buy" button, but it's also the smallest text on the page.

If shipped direct from those people helping Russia, Customs could intercept and confiscate the items (if they had unlimited resources). But Amazon's warehouses are able scoff the law due to legal chicanery. (government agencies must choose their fights carefully, lest they have to go back to Congress to ask for more funding for lawyers).

But it says UL!

If I build you a "Suicide Cord" using two UL-listed NEMA 14-30 plugs and UL-listed 10/4 cordage, is that assembly UL-Listed? LOL of course not, UL doesn't list suicide cords for obvious reasons.

Same deal here. All they are claiming is that instead of using random Chinese cordage, they are actually getting a proper UL-listed 10/3 cordage imported. That may or may no be true, but by making the claim that particular way, they make it difficult for UL's lawyers to force them to stop.

But that assembly is absolutely not UL-Listed. No way, no how. The item will not have a label on the cord indicating UL Listing.

But all they need to do is say a little for "wishful thinking" will take over. We live in a post-fact world. Reality is anything you want! Don't like who won the election? Easy, they didn't win the election! Don't want to believe humans are causing climate change? Blame it on anything! Don't want to wear a mask? Germ theory is only a theory! So that listing will nicely appeal to that sensibility.

  • Would UL approve an adapter which allowed use of a 4-prong plug with a 3-prong outlet, if the adapter included a ground fault circuit interrupter? I would think that such an adapter should be fairly safe, under the same principle that allows upgrading 15/20-amp outlets with a "no equipment ground" GFCI.
    – supercat
    Commented Jul 30, 2023 at 18:25
  • @supercat I can't see why not, unless there's an issue with the GFCI controls being inaccessible. Commented Jul 30, 2023 at 18:41
  • @supercat: I saw some old instructions with a four prong dryer that said if you have a three prong outlet, save the cord from your old dryer, attach leads from old cord (they're donut hole leads that slip over bolts with nuts you tighten down), and run the included banana connector from the fourth bolt to a screw on the outlet face. Clearly this would only work if said screw were grounded. They got this approved somehow.
    – Joshua
    Commented Jul 31, 2023 at 4:00
  • @Harper-ReinstateMonica: It would be nice if UL could recognize more kinds of protective equipment that could enhance the safety of older wiring without requiring that it be reworked to modern standards. A GFCI-protected dryer outlet with an 18ga grounding pigtail in series with positive-temperature-coefficient resistor and solid-state current limiter would provide better safety than a dryer outlet with a full-size grounding conductor but no GFCI, or one with a GFCI and no grounding connection, but I don't know of any standard for such devices.
    – supercat
    Commented Jul 31, 2023 at 16:33

Amazon sells stuff all over the world from vendors all over the world so what's legal elsewhere might not be legal here in the USA. In the USA, it would have to be UL listed to be used. You'd have to check the listings for each adapter to see if it qualifies. Amazon is famous for selling junk that's not UL listed and since you don't have a link to the adapter, we can't check it.

  • Here is the link: amazon.com/Adapter-14-30R-Female-10-30P-Converter/dp/B08PFCSDWV/… Apparently it does meet the UL requirements or at least says it does as indicated by this description: "【SAFETY】 The dryer plug adapter that meets the UL standard has a copper core that meets the quality requirements of STW 10/3 AWG and a durable insulating PVC protective layer."
    – Fred
    Commented Jul 29, 2023 at 15:10
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    Sellers often lie. (Although I have no idea whether this device, or any comparable device, is UL listed for use in the United States. But sellers on Amazon have zero accountability to anybody, and can say whatever they want.) Commented Jul 29, 2023 at 15:35
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    Self declaring it ‘meets the standard’ is not the same as actually having it pass the tests and be listed. Exactly what it is listed under also matters.
    – Jon Custer
    Commented Jul 29, 2023 at 16:04
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    It seems unlikely that UL would truly approve of obtaining ground for a 30A circuit from a 15A circuit, as this device enables. The NEC definitely doesn't allow retrofitting ground for a 30A circuit to a 15A or 20A ground.
    – nobody
    Commented Jul 29, 2023 at 16:46
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    @Fred It doesn't actually say it's UL listed, which is what is needed. All that statement says is that they claim the main cable (not the green ground wire) is STW 10/3. That has no bearing on whether or not the adapter is UL listed.
    – Armand
    Commented Jul 29, 2023 at 16:55

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