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SlowBro's avatar
SlowBro
Explorer III
Feb 27, 2015

Safe to run 20A through a 15A adapter?

Can a 20A load be safely run through a 15A adapter? I want to be able to run our A/C off my 120V x 20A 3000W generator without a meltdown, and I know a 15A plug will physically fit in the socket, but I wonder if the extra current will cause problems.

I have one of these dogbones that I bought for $8. The description says, "Connects a 30 amp RV power cord to a 15 amp shore power box, outlet, or generator with 15-20 amp duplex receptacle." But I think they are only saying it will physically fit, not that it is electrically rated.
30 Amp Female to 15 Amp Male RV Pigtail Power Adapter

The title on this item says it is rated at 20A but the picture clearly shows that it's only rated at 15A. Maybe Home Depot is mistaken, or maybe a 15A adapter can be safely used for 20A?
PowerFit 20A 120-Volt to 30A RV Outlet Adapter

I found this item which is clearly rated for 20A; It even has the 20A sideways blade. But it costs $33. I'd rather not have to buy another RV thingamabob if I don't have to, or if there is a $10 solution.
Conntek RV Generator Adapter with 20 Amp Straight Blade Male 5-20P Plug To RV 30 Amp Female Connector

Here's an inexpensive adapter. The description claims either 15 or 20A. The model name is AD3020 which to me implies 30A to 20A. But like the Home Depot item you can see it is stamped with a 15A rating.
RV ADAPTER AD3020

The same item is available on Amazon, where only 15A is listed.

Is my only option the $33 unit or can my 15A dogbone be safely used with a 20A load?

33 Replies

  • cdevidal wrote:
    Can a 20A load be safely run through a 15A adapter?
    I think you're just going to have to try it and see. And by 'see', I mean making sure the plugs aren't getting hot. It'll be obvious if the generator won't do it.

    Do you know for sure your air is 20a?
  • If I were you, I'd stick with the Conntek, beefier unit. Especially if you're going to run the air.


    The one above is likely to overheat melt, and just aren't made as well to start with!

    Other people will chime in with other "dogbone" solutions too!
  • Strictly speaking I'd say no you shouldn't run 20A through a 15A adapter but given the ambiguity in what I've found with other adapters I'm not clear there is a problem doing this or not. The cable on the dogbone I have looks very thick, so maybe it can handle the extra amps?