I have a dedicated 20 amp circuit next to where I park my MH when loading and unloading for trips. If only some 12 volt lights, but no frig or water heater on electric were running in the mh, could I run 1 of the roof top ac’ units? Both units are on single 20 amp breakers in the MH and one is 15,000 btu and one is 13,500 btu. Thanks in advanceAdditional info I have a 30 amp extension cord with an adapter to 20 amp that I could use.

Possibly. Are you using an extension cord?

With a short extension cord and nothing else drawing power except led lights, yes.

Yes. It too is rated for 20 amp.

I think you'll need a 10awg extension cord.

be sure to turn off the charger portion of the charger/converter else it trips your circuit. i know from experience.

Running 1 ac unit on 20 amp shore power, | Good Sam Community

MitchF150
Explorer III
Jul 22, 2019
Best to check your voltage when plugged into whatever configuration you have and go from there...

If you plug in and then turn on the AC get a volt meter and plug into any other 120v outlet in the rig and read it's voltage output..

If it's much below 108v, then you might need to consider some other power source, but for a short time, and if it does not trip the 20a breaker then you are probably "ok"...

No way to say for sure one way or the other, but you can also feel the cords and if they are really warm to the touch, then maybe you are drawing too much...

Good luck!

Mitch
Dirtclods
Explorer
Jul 22, 2019
You'll be fine I'm plugged in at home on a 20 amp as you said you Have your ~ 30 amp extension cord with an adapter to 20 amp .

https://www.amazon.com/Yellow-Jacket-2991-Generator-T-Blade/dp/B000HEC2DW/ref=sr_1_3?crid=3Q3RDKR86UKF8&keywords=heavy+duty+extension+cord+50+ft+20+amp&qid=1563755677&s=gateway&sprefix=heavy-duty+extension+cords+20+amp%2Caps%2C209&sr=8-3

https://www.amazon.com/Camco-PowerGrip-Adapter-Contoured-55223/dp/B00192JGA8/ref=sxbs_sxwds-stvp?keywords=220v+to+110v+converter+rv&pd_rd_i=B00192JGA8&pd_rd_r=66881beb-3f4c-492a-8487-bb3f43b0c1a0&pd_rd_w=xSDnN&pd_rd_wg=uZGOk&pf_rd_p=a6d018ad-f20b-46c9-8920-433972c7d9b7&pf_rd_r=YVT7CEMTNJDP9V4RD28R&qid=1563756454&s=gateway

And if you worried about a fuse you can just use a power strip it'll do the same thing.
Cummins12V98
Explorer III
Jul 22, 2019
Yup no problemo.
Lwiddis
Explorer II
Jul 22, 2019
Short and 10 gauge, 2oldman.
rk911
Explorer
Jul 22, 2019
and what difference does using an adapter make? if the OP draws more than ~80% of 20-amps (16-mps) the CB will pop.
road-runner
Explorer III
Jul 22, 2019
MitchF150 wrote:
Best to check your voltage when plugged into whatever configuration you have and go from there...

If you plug in and then turn on the AC get a volt meter and plug into any other 120v outlet in the rig and read it's voltage output..

If it's much below 108v, then you might need to consider some other power source, but for a short time, and if it does not trip the 20a breaker then you are probably "ok"...

No way to say for sure one way or the other, but you can also feel the cords and if they are really warm to the touch, then maybe you are drawing too much...

Good luck!

Mitch

This answer gets my vote as the best. I check the voltage inside the rig, and it works out ok for me.
etrippe
Explorer
Jul 22, 2019
Thanks everybody. I have a plan and will try it tomorrow. Again thanks everybody for responding
2oldman
Explorer II
Jul 22, 2019
GFI circuits don't work well.
RLS7201
Explorer II
Jul 22, 2019
rk911 wrote:
and what difference does using an adapter make? if the OP draws more than ~80% of 20-amps (16-mps) the CB will pop.

No it won't. Look at the trip curve. That 80% deal is nonsense.

It will carry a multiple of 1.13 for ever.

Richard
BB_TX
Nomad
Jul 22, 2019
RLS7201 wrote:
rk911 wrote:
and what difference does using an adapter make? if the OP draws more than ~80% of 20-amps (16-mps) the CB will pop.

No it won't. Look at the trip curve. That 80% deal is nonsense.

It will carry a multiple of 1.13 for ever.

Richard

Correct. 80% may be recommended max loading. But breakers don’t trip until the current exceeds the rated amps.