# Generator Adapter Plugs



## TravelinTexas (Apr 30, 2010)

View attachment 20 amp adaptor.doc
For those with more electrial knowledge than myself, I have a Yamaha ef2400is generator that has two 20amp plugs, is it necessary to use a 20 amp generator adapter plugged into the gen. unit with the 30amp trailer cord plugged into the back of the adapter which enables you to get 20 amps of power? I am currently using a 30amp female/15mw male adapter plugged into my gen unit. No luck in starting my 13.5 Coleman Mach A/C unit(I believe the problem lies with the lack of a hard start capacitor which will be installed soon). I was just wondering if the 15amp adapter that I use at my home when the trailer is powered up at the house unable to get the true 20amps from the generator because I am using a 15amp adapter plug? Just curious....just trying to avoid buying another $20 adapter if it isn't necessary.


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## hautevue (Mar 8, 2009)

The wire size is the issue. 15 amp wire is #14 and 20 amp wire is #12. It's likely that the adapter is wired with #14--it costs the manufacturer a smidge less per adapter. But maybe you are fortunate and the manufacturer used a heavier cable that has #12 or #10 wire.

30 amp wire is #10. My 30 amp shore cable is made with #8. Apparently for added safety, the manufacturer used a slightly bigger cable...

You can run 20 amps through #14 wire, but it will get warm "fer sure". It's not ideal, especially if the wire is enclosed, as in a wall. But you don't have that issue. Just note that it does not meet electrical code to use #14 wire in a 20 amp circuit.

Most TT a/c systems draw heavily only on starting as you know. So if it were my decision, I'd go for it and try it out.

Check the output voltage: run the gen without the adapter and measure the output voltage. Then plug in the adapter and measure the voltage again before you plug in your shore power cable. If the voltage drop is significant (like 117 to 110 or so) just going through the adapter, then I would not use it to drive a 20 amp circuit. If the voltage drop is trivial (like 117 to 115) then you can try it.

But the real test is the warmth--warm says the wires are unhappy with that amount of power and are dissipating the energy as heat...


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## CamperAndy (Aug 26, 2004)

This applies to all the people trying to start the AC with a generator and especially those trying with just enough generator to do the job.Recheck ALL junctions in the circuit to make sure that they are tight. Even if it is just a little loose it results in voltage drop and that hurts your chances of it working.

Check all the following spots

30 amp termination where it comes into the trailer.
30 amp incoming to the converter
All breakers in converter
All grounds in converter
Frame ground for converter (check all around trailer frame for the ground lug)
Power and neutral at the AC.

If you can not see good contact you may even want to take the connection apart and re terminate it. You never know what Gilligan was thinking about when he made up the electrical connections.


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