Coach is stored at my business (warehouse) and plugged in 7/24 to a 20 amp receptacle. I would like to pre-cool before hitting the road for a day or two. I can reach 2 different (not on same circuit) 20 amp outlets via extension cords easily to utilize one of these LinkAny harm in running one AC and nothing else safely through one of these? Am I missing something?

No, you will still only have ONE 20 amp outlet feeding the a/c. It will not combine the two outlets to up the amp supply. One side feeds one side of the panel box the other plug the other.

katysdad wrote:No, you will still only have ONE 20 amp outlet feeding the a/c. It will not combine the two outlets to up the amp supply. One side feeds one side of the panel box the other plug the other.Well if I end up with a clean 20 amp for each side isn't that still more than I would have when I am @ a RV park that only has 30 amp? Anyone can run one AC no problem with 30 amp right?

One air conditioner should run on a 20amp circuit .

If the AC runs on the 20A plug then you don't need the cheater cord. In general a RV AC will run on 20A. But getting them started is the issue. AC's have a large startup surge load. Smaller ACs may start on 20A but don't expect that for all ACs. Plus for any large AC load like a AC you need to make sure the voltage with the AC running is within spec. Low voltage can/will damage a AC.There are many threads on the cheater cord. You might want to search and be sure to search more than one year ago.

Electrical plug cheater box | Good Sam Community

33 Replies

wa8yxm
Explorer III
Aug 30, 2013
The big problem with the cheater box. NOTE there are exceptions I'll post two.

Normally on a 30 amp site you have 30 and 20 amp outlets (sometimes only a 30) and the 20 amp is NORMALLY a GFCI (older grandfathered parks may not have GFCI)

NO Gfci, they work well

GFCI, they trip .. if they do not trip the GFCI something is wrong with the GFCI

30 amp outlets are not normally GFCI, however that said, exceptions do exist.

IF you can plug into two 30 amp outlets.. It works great, I've done it

One place is a spot I park 2x a year, I'm there in the "off" (Just before/after) season Folks start pulling in just as I leave, or leave just before I pull in so I can normally grab two sites Some of the sites however are GFCI,,,, I need to avoid those.

Another place is the Thousand Trails park in Las Vegas in August.. My understanding (I was there in Jan/Feb) is that in the hot season they assign every other site and encourage you to use the cheater box so you can run both A/C's.

I must say I like that park manager.
Two_Jayhawks
Explorer
Aug 30, 2013
Thanks to everyone for the input. I should have known anything electrical always brings many different comments. I dumped the extension cord and dragged the 50 amp cord from the coach right to the 20 amp outlet. I turned everything else onboard off as before (fridge on LP)and turned on the AC again. It's been running all day and seems to be fine. I am already planning to bring a 50 amp plug in. Thanks again.
jhilley
Explorer
Aug 30, 2013
But that neutral is sized for 50 amps same as L1 and L2. Technically could be a problem with two 30 amps maxed out, but practically probably not. With 30 amp and 20 amp, it would carry a maximum of 50 amps.
randallb
Explorer
Aug 29, 2013
The 20/30 inputs are what bother me. I built a double 30 input to 50 amp output box for use at the CG in my wife's home town. The monuments were set up with 2-30A outlets on opposite phases. This way they can run 2 30A RVs off of one monument. In this situation I would and did use a cheater but I would not try to run a 50A RV off of a 20 and 30 even though it would work in theory if they are of opposite phases. Remember your single neutral in the box must carry both legs of the 120. That is why they need to be out of phase.
Randy
katysdad
Explorer
Aug 29, 2013
wolfe10 wrote:
katysdad wrote:
Passin Thru wrote:
You have 40 AMPs going to a 30 amp circiut. It will work.

You will never have 40 amps from 2 20's. 20 amps is 20 amps.period.

If the RV is 30 amps (i.e one hot) you are correct. And, you would gain NOTHING. And, if the two 20's were from opposite sides of the building breaker box, you would "let the smoke out"!

If the RV is 50 amps and L1 is 20 and L2 is 20, you WILL have 40 amps available.

Only 20 amps PER LEG. If any combination of appliances pulls more than 20 amps on either leg it will kick the breaker for that leg if utilizing a 20 amp circuit as the OP was inquiring about.

Do it right the first time and install a dedicated outlet for the MH or TT. Have seen too many instances where the proper way would have been cheaper than what was spent on "cheater devices" even before damage to the RV was repaired. It's a wonder some of these people aren't electrocuted with some of the concoctions they can dream up.
wolfe10
Explorer
Aug 28, 2013
katysdad wrote:
Passin Thru wrote:
You have 40 AMPs going to a 30 amp circiut. It will work.

You will never have 40 amps from 2 20's. 20 amps is 20 amps.period.

If the RV is 30 amps (i.e one hot) you are correct. And, you would gain NOTHING. And, if the two 20's were from opposite sides of the building breaker box, you would "let the smoke out"!

If the RV is 50 amps and L1 is 20 and L2 is 20, you WILL have 40 amps available.
katysdad
Explorer
Aug 28, 2013
Passin Thru wrote:
You have 40 AMPs going to a 30 amp circiut. It will work.

You will never have 40 amps from 2 20's. 20 amps is 20 amps.period.
CA_Traveler
Explorer III
Aug 28, 2013
Passin Thru wrote:
We have 2 30 amps running to a splitter and plug the main 30 amp of ours into it. Works effectively so don't worry about what people say won't work. You have 40 AMPs going to a 30 amp circiut. It will work.
Per Brett I also don't understand your setup.

Also just because something words for someone does not mean that it's OK or everyone. Some items like the cheater cord have pitfalls depending upon how they are connected and used and I don't suggest their use for that reason.
CA_Traveler
Explorer III
Aug 28, 2013
wolfe10 wrote:
rgatijnet1 wrote:
Trying to wire in two 20 amp circuits to your 50 amp input may confuse your EMS board and shut things down.

No first hand experience with EMS systems, but wouldn't the following be true:

If the two hots are on the same "Phase" (i.e. from same side of warehouse breaker box) the EMS would assume 30 amp service.
Correct.

If the two hots are on different "Phases" (i.e. from opposite sides of the warehouse breaker box) the EMS would assume 50 amp service.
Correct.

Can't see a problem with running loads the OP is discussing: one A/C plus probably the refrigerator (though that could be on propane) and the charger which should be pulling minimal amps since it has been plugged in long enough to have the batteries fully charged.
Very easy to start running heavier loads which may cause issues.

Again, IF the refrigerator and/or converter or other loads to be run are on the "other hot" (not same one running the A/C) this cheater makes sense (assuming his warehouse outlets are not GFI). If ducted A/C that would merely mean verifying which A/C and other circuits run from which hot.
Two_Jayhawks
Explorer
Aug 28, 2013
I believe I will go ahead and bring a 30 amp outlet to the coach. I suppose I hadn't because I rarely use the 50 amp I had installed at home. Leaving in triple digit temps sure changes that.

Forum Discussion

Electrical plug cheater box

33 Replies

About Motorhome Group

Related Content

Electric

7 pin plug amperage rating?

Electric Cheater Box

"cheater" plugs

Electrical assistance