30 amp & 20 amp to make 50 amp

his question just scares me to death.

Lantley wrote:

ScottG wrote:

MrWizard wrote:
the OP did not mention WH

My point was to run some load in your rv off the 20A recpt. at the pedestal instead of running everything off the 30A.
Could be a Wh, space heater, toaster oven, Margarita blender, etc.

I use a RV Safepower
transfer switch to supplement my power when I'm caught with my 50 amp RV on a 30 amp site. I can run my 2nd A/C or Washer/Dryer circuit via the RV safe power transfer switch. I typically plug my space heater into the W/D circuit. The switch works with GFCI outlets.
The RV Safepower is a game changer. 30 amp site are no longer a deal breaker for me. Bring on the state parks.

HOLY ****! For $350.00 I will move plugs to switch power.

Here is an automatic transfer switch that cuts off power to load #2 whenever load #1 is turned on, and for less than $90.

Intellitec Power Management System Control Module

Bobbo wrote:

Lantley wrote:

ScottG wrote:

MrWizard wrote:
the OP did not mention WH

My point was to run some load in your rv off the 20A recpt. at the pedestal instead of running everything off the 30A.
Could be a Wh, space heater, toaster oven, Margarita blender, etc.

I use a RV Safepower
transfer switch to supplement my power when I'm caught with my 50 amp RV on a 30 amp site. I can run my 2nd A/C or Washer/Dryer circuit via the RV safe power transfer switch. I typically plug my space heater into the W/D circuit. The switch works with GFCI outlets.
The RV Safepower is a game changer. 30 amp site are no longer a deal breaker for me. Bring on the state parks.

HOLY ****! For $350.00 I will move plugs to switch power.

Here is an automatic transfer switch that cuts off power to load #2 whenever load #1 is turned on, and for less than $90.

Intellitec Power Management System Control Module

Not quite the same function as the Safepower transfer switch.
I'm not trying to share a breaker between appliances. I am allowing the 20 amp pedestal breaker supply electric for my A/C or heat in lieu of the main 50 bamp circuit. It allows the 20 amp circuit to supplement the 30 amp circuit which is what the OP is wanting to do.
Once you understand what it does the price become unimportant.
It allows a large RV's to operate on a 30 amp site and run both A/C's without issue.

yes adapater , i thought 30 & 20 on same hot leg , i have a 30 to 50 & just better to use 30 to 50 & run w.h. & frg on propane , tks ..

I've worked on 50A campground pedestals, but I didn't notice if the 30A and 20A receptacles were on opposite legs of the 50. If it's 30A only, then only one leg is available so 30 and 20 would be on the same leg, the same CG circuit, same CG breaker...

Bud's point above is oft understood. 30A x 120V = 3600 Watts, but 50A is served by TWO 50A circuits so it's really 100A and 50 x 120 = 6000 TIMES TWO or 12000 WATTS! That's why going from 30 to 50 is such a game changer.

enblethen wrote:
The two circuits must be on different phases of the electrical source.

Split phase is not needed for the 30+20 amp cheater cord connection as the 50A RV neutral cannot be overloaded.

You could argue that the cheater cord connected to 30+30 amp (which I've done) could overload the 50A rated neutral if the connection is not split phase.

Update: I was referring to the RV neutral and should clarified that the shorted adapter neutrals can by overloaded.

I don't recommend using the cheater cord because there are potential electrical and safety issues that are not understood by most RVers. But as the saying goes if you build it they will buy it. And as stated it doesn't work if a GFCI is involved.

Much better to install a independent 20A circuit in the RV and connect it with an extension cord to a 20A pedestal plug. That circuit could be set up so that a second A/C can be switched to this circuit.

CA Traveler wrote:
I don't recommend using the cheater cord because there are potential electrical and safety issues that are not understood by most RVers. But as the saying goes if you build it they will buy it. And as stated it doesn't work if a GFCI is involved.

Much better to install a independent 20A circuit in the RV and connect it with an extension cord to a 20A pedestal plug. That circuit could be set up so that a second A/C can be switched to this circuit.

That is how the RV Safepower transfer switch operates.

CA Traveler wrote:

enblethen wrote:
The two circuits must be on different phases of the electrical source.

Split phase is not needed for the 30+20 amp cheater cord connection as the 50A RV neutral cannot be overloaded.

You could argue that the cheater cord connected to 30+30 amp (which I've done) could overload the 50A rated neutral if the connection is not split phase.

I have a different understanding of the question than you do. I understand that he has a 50 amp RV and wants to use this on a pedestal without a 50 amp outlet, but use the cheater to at least get 6000 watts. In this case, there is no 50 amp neutral. The 30 amp neutral definitely can be overloaded, if the 30 amp and 20 amp outlets are not fed from the same main breaker, but are still on the same leg.

As far as 50/30/20 amp boxes, I bet if you check 100 of them, you will find some that have the 30 and 20 outlets on the same leg, and some that they are on different legs. There will be no uniformity.

Bobbo wrote:
...........
In this case, there is no 50 amp neutral. The 30 amp neutral definitely can be overloaded, if the 30 amp and 20 amp outlets are not fed from the same main breaker, but are still on the same leg.
.............

Actually there is a 50 amp neutral all the way from the RV load center to the end of the 50 amp cord where it would plug into the adapter. Then the neutral splits into a 30 amp neutral to the 30 amp plug and a 20 amp neutral to the 20 amp plug. And those two neutrals would connect inside the pedestal.