Electric Cheater Box

Yes

Here is a neat discussion about your subject line...

CHEATER ADAPTERS

I added some diagrams of the various cheater cords in this link...

The one that scares me the worse is having two MALE PLUGs on one end and a FEMALE SOCKET on the other like when using one of these adapters.



What you don't want to happen is plug in one MALE PLUG to a 30A Pedestal and then read a 120VAC potential on the open OTHER MALE PLUG on the 20A Plug. Having a HOT MALE plug laying around can be real dangerous...

Normally if you plug in both of the MALE PLUGS first and then plug your 50A Trailer plug into the adpater next will solve this problem...

If you don't flip your main 50A Breaker in the trailer and plug one of the MAL PLUGS into the source you may indeed have a 120VAC POTENTIAL on the other MALE PLUG before you plug it into the source. I would think plugging in BOTH MALE PLUGS first and then plugging in the 50AMP Trailer MALE PLUG into the FEMALE SIDE of the adpater next would be the safe way...

I have no idea how the Electic manageent systems or GFCI receptacles on your trailer react to the adapters... I think it depends on how the camp ground pedestals are wired up. Normally the 30A receptacle and the 20A Receptacle are wired on the same hot leg of the pedstal fed by separate breakers is what I have found...

Reading the above link you see alot of modifications to the varios situations is done to make this idea work at the various different wired up camp ground pedestals...

Like I said in the link listed above "Be safe out there" haha...

Hope my diagrams and pictorials listed in the above link helps

The only RV ADAPER I have played with any is the RV30A-15A ADAPTER to hook up my POPUP trailer to my 2KW Honda generator to charge my batteries... It is pretty straight foward...


Roy Ken

Every time this comes up, I feel the need to remind folks that although this cheater cord gets you 50 amps at your 50 amp plug, 50 amps service at the pedestal is 2-50 amp circuits for a total of 100 amps. Using the cheater gets you HALF the normal amps.

RoyB wrote:
Here is a neat discussion about your subject line...

CHEATER ADAPTERS

I added some diagrams of the various cheater cords in this link...

The one that scares me the worse is having two MALE PLUGs on one end and a FEMALE SOCKET on the other like when using one of these adapters.



What you don't want to happen is plug in one MALE PLUG to a 30A Pedestal and then read a 120VAC potential on the open OTHER MALE PLUG on the 20A Plug. Having a HOT MALE plug laying around can be real dangerous...

Roy Ken

I don't disagree in the least that having a hot male plug is a very dangerous situation (and not permitted by code). However, assuming everything is wired properly and there are no 240V appliances in the RV, this cheater cannot create a hot male plug under any usage condition. If one or both of the outlets are miswired, say by having their hot and neutral reversed, then it can have a hot male plug, and cause other problems like producing a dead short when both plugs are inserted. That's true regardless of whether there's an RV connected.

The bigger problem is that these create a sort of ground fault by bridging the neutrals. (It's not technically a ground fault, since it's not current flowing through the ground that shouldn't be, but it properly trips a correctly working GFCI.) Should one of the neutrals to one of the campground sockets be open or have a high impedance, it's quite possible to significantly overload the other neutral, particularly if the two sockets are on the same phase which is quite common. You could have a 50A current on the 20A neutral line without tripping any circuit breakers.

I would not feel comfortable using one of these cheater cords. I'm rather surprised they're permitted at all, to be honest.

I don't understand the part that says

want-a-be wrote:
......If I switch the 30 amp plugs around on the cheater box will the AC be pulling off the 30 amp?

If you cheater box has two male 30 amp plugs and you use a 30 to 20 amp adapter on one of those male plugs (to adapt one of your 30 amp plugs to the campgrounds 20 amp outlet), then yes, switching the 30 amp male plugs will move the A/C to the other phase (if the pedestal is wired using two phases).

NOTE: I can see where a "cheater box" could come in handy but a understanding of A/C wiring and a meter would seem to be a necessity. I would think the campground panel would need to be tested for proper wiring before using the adapter and anyone using such a device should know which side of the adapter would benefit from the 30 amps and which side could still function on the 20 amp phase. If I expected to have to use one of these devices< I might even move some of the wiring round in my RV's panel so I could "adjust the loads" to cope with the 20 amp phase.

EDIT: One more thing to worry about is the cheater plug is hanging out in the rain. Isn't that lovely?

If I owned a campground these devices would not be permitted.

Yeah, leaving the male plug out would be dangerous on several accounts. Do you have a photo of the box you are working with?

X2 DrewE...

TNGW1500SE _ I am assuming the OP has the largest air conditioner he wants to use being fed by the 20AMP side so he wants to swap the two zones so the 30A side is feeding his air conditioner he wants to run???

The standard RV 30A to 50A adapter has the two HOT ZONES shorted together in the 50A side of the adapter. This then sends 30A power down both 50AMP zones in the trailer. Of course if you draw more than 30A by using both zones the 30A breaker on the pedestal will trip. But at least both zones are powered up inside the trailer


google image

Using the dual cheater cable, one zone will be fed by 30A source and the other will be fed by 20A source...


google image

Guess that all makes sense haha...

Roy Ken

RoyB wrote:
....I am assuming the OP has the largest air conditioner he wants to use being fed by the 20AMP side so he wants to swap the two zones so the 30A side is feeding his air conditioner he wants to run???....

That's what I "assume" as well. If his cheater has two 30 amp male plugs, he could just switch them in the CG panel.

If it was that simple, I would think he'd had already tried it and not required a post here.

If he has one 30 and one 20 amp male plug, he's going to have to switch his A/C breaker to the opposite phase by moving the breaker in the RV's panel or rewiring his 50 amp plug by switching the hots.

Seems like we're both having to "assume" a lot when it comes to answering such a important question.
:h

Maybe he'll post more info. I'd be interest in knowing what he has.

PS: I see no problem with these:

With these types of adapters, if either the 20A or 30A receptacles are protected by a properly functioning GFCI, then it will trip as soon as the second male plug is connected. The GFCI will detect the shared neutral connection and open the circuit.

DrewE, while I agree with most of your summary, I believe there CAN be a situation where a male plug WILL heat up. Let's assume there's 15Amps flowing into the 20A male plug and 25A flowing into the 30A male plug. Both 20A and 30A breakers think everything is OK and will not trip. However, the neutrals to each plug are connected together and there is no way to determine HOW that 40A of combined current will get back to the neutral in the power pedestal. Maybe it'll split 15A/25A just like it did through the hots OR maybe it'll flow 10A through the 30A neutral and 30A through the 20A neutral. There is no way to be sure, and since the breakers don't protect the neutral wiring, there definitely could be an overheating and potential fire hazard issue should this occur.

I have been to campgrounds that do not allow these types of adapters and I believe the above reason is why.

Also, if both the 20A and 30A receptacles are protected by the same 30A breaker, then you're still limited to a total of 30A. Probably not standard, but I've seen some interesting campground wiring.

I have only been able to use ours in 2 campgrounds. One was so old the 20A circuit didn't have a GFCI on it and the other is a newer section in an older campground where each spot has 2 30A receptacles, but the hots of each are out of phase (i.e. 240VAC across them). So using the adapter effectively provides me with a 30A 240VAC connection, instead of the standard 50A 240VAC service. Still better than 30A 120VAC. :) And the campground is fine with me using the adapter.

~Rick