30 amp 240 volt mistake!!

[mxdad777]

I recently bought a 2018 Rockwood 5th wheel with a 50 amp service. I have a 240 v 50 amp outlet in my RV cover that I’ve used for years to plug my motorhome into. Since I still have my motorhome and it’s parked in the RV garage I decided to hook up my 5er temporarily to my 30 amp 240 volt welder outlet. I had no idea that RV 30 amp cords were 120v only. Long story short, after connecting my 30 to 50 adapter I sent 240 volts down one leg of the buss bar. So everything on that side of the bus bar received 240 volts while the other side received zero. My question now is what will I need to replace? My refrigerator, GFCI, rooftop A/C were all on that side. The A/C seems to be working fine, but the fridge isn’t and the GFCI is smoked. Although I’ve wired up many homes, I certainly learned something about RV’a and their wiring today. I’m hoping just the circuit board on the fridge can be replaced. Anyone else have any experience with this? I’m sure this can’t be the first time this has happened. Stupid me!!

[DrewE]

mxdad777 wrote:

camper1013 wrote:
Sorry for your troubles.

I think someone mentioned it already, But I will suggest a EMS unit (Progressive Industries makes a good one). I had a hard wired one in my last camper, and it was the first thing I put in my new one. It will cut power to save the rig in the event something like this happens in the future. I have not run into issues with miss wiring yet, but have had too low of voltage at older camp grounds.

Yes, my converter was smoked too. It was a cheap one anyway, so I just ordered a new Progressive Dynamics PD9260CV Inteli-Power 9200 Series Converter/Charger with Charge Wizard - 60 Amp to replace it.

Good choice on the converter; the PD ones are spec'd to shut off and not do anything bad for overvoltage conditions up to 240ish volts nominal.

Do be aware that an EMS and the converter are quite separate and different things (and Progressive Dynamics and Progressive Industries are likewise two entirely different companies, albeit with confusingly similar names). An EMS, at least as discussed here, is a gizmo that is installed somewhere around the electrical inlet of the RV and monitors the voltage, frequency, etc. of the incoming power and disconnects it--or refuses to connect it initially--if it's not correct. There are also some more sophisticated Electrical Management Systems that higher-end RVs may have that perform additional tasks like load shedding based on the available power (for instance, disabling the electric element in the water heater for a 30A shore power connection, or preventing simultaneous use of multiple air conditioners under similar conditions).

[allwthrrider]

I did this years ago with my Class C, Heard a pop & that was it. I got away with just replacing the power panel where your CB's & Fuses are located, Nothing else was damaged.

[2naEagle]

mxdad777 wrote:


Yes, my converter was smoked too. It was a cheap one anyway, so I just ordered a new Progressive Dynamics PD9260CV Inteli-Power 9200 Series Converter/Charger with Charge Wizard - 60 Amp to replace it.

You will also need a EMS I like the hardwired.

[mxdad777]

camper1013 wrote:
Sorry for your troubles.

I think someone mentioned it already, But I will suggest a EMS unit (Progressive Industries makes a good one). I had a hard wired one in my last camper, and it was the first thing I put in my new one. It will cut power to save the rig in the event something like this happens in the future. I have not run into issues with miss wiring yet, but have had too low of voltage at older camp grounds.

Yes, my converter was smoked too. It was a cheap one anyway, so I just ordered a new Progressive Dynamics PD9260CV Inteli-Power 9200 Series Converter/Charger with Charge Wizard - 60 Amp to replace it.

[camper1013]

Sorry for your troubles.

I think someone mentioned it already, But I will suggest a EMS unit (Progressive Industries makes a good one). I had a hard wired one in my last camper, and it was the first thing I put in my new one. It will cut power to save the rig in the event something like this happens in the future. I have not run into issues with miss wiring yet, but have had too low of voltage at older camp grounds.

[Wild_Bill_888]

RoyB, thanks for the graphics. When it comes to electrons a good schematic is worth a thousand paragraphs.

[Old-Biscuit]

mxdad777 wrote:
Ok, after replacing both of my GFCI receptacles it appears everything works except for the refrigerator. It looks like all outlets ran through the GFCI receptacles first and so they became the sacrificial child. Lucky there, $40 and I’m back in business for most of the RV. The converter is fine because it was on the buss bar that received no power. So my fridge is the problem. I know I have good power to the fridge receptacle, but the fridge is giving me an error code E3. I get the code regardless if I try LP or 120v. The make is Dometic and the model is RM1350SLMX. I googled E3 code and it talks about a recent button, but I don’t believe this fridge has the reset button I read about. Any ideas how to clear the E3 code or is my circuit board toast?

If you are facing the back of the refer just above the burner there is a heat limit switch on the boiler with a reset button in the center.
It is about the diameter of a quarters and there is a red button in the center.
Push it. this is a heat limit switch. In real hot weather it might pop turning the unit off.
Are the fans still working?
Are the vents clear?
Anything that will cause the unit to get hotter than normal might pop the heat switch.

[time2roll]

mxdad777 wrote:
My question now is what will I need to replace?

Test everything that runs on 120v. Replace as needed.

Start with testing the converter. BTW if it is a WFCO and has failed do yourself and battery a favor and replace with a better brand. Progressive Dynamics, IOTA or Boondocker.

[CA_Traveler]

Actually a 50A RV plug is 120/240V 4 wire 3 pole 50A circuit. And just like the typical 4 wire home circuit 120V or 240V or any combination of the 2 can be used. Think about a home oven with 120V lights and 240V heating coils.

Some RVs install a CB panel that doesn't allow the installation of a dual CB (for 120/240V appliances) while other RVs like a home don't have that restriction.

[kaydeejay]

Edd505 wrote:
"I have a 240 v 50 amp outlet in my RV cover that I’ve used for years to plug my motorhome into" ---- Just how did that work?? 240 motor coach?

While it is possible to draw 240V power from that 50A receptacle it strictly speaking is a dual 120volt system.
Refer to the drawings posted above by RoyB and you will see there are TWO 120 volt hots, a neutral and a ground.
The majority of your RV systems will run off one side or other of this arrangement using 120 volts. (Some high end RVs may use 240V between the two hots to power some appliances).
But back to basics - it's exactly the same arrangement as a typical home system where all your wall outlets are 120V but those for a stove or dryer will be 240.
Make sense now?

[mxdad777]

Edd505 wrote:

mxdad777 wrote:
I recently bought a 2018 Rockwood 5th wheel with a 50 amp service. I have a 240 v 50 amp outlet in my RV cover that I’ve used for years to plug my motorhome into. Since I still have my motorhome and it’s parked in the RV garage I decided to hook up my 5er temporarily to my 30 amp 240 volt welder outlet. I had no idea that RV 30 amp cords were 120v only. Long story short, after connecting my 30 to 50 adapter I sent 240 volts down one leg of the buss bar. So everything on that side of the bus bar received 240 volts while the other side received zero. My question now is what will I need to replace? My refrigerator, GFCI, rooftop A/C were all on that side. The A/C seems to be working fine, but the fridge isn’t and the GFCI is smoked. Although I’ve wired up many homes, I certainly learned something about RV’a and their wiring today. I’m hoping just the circuit board on the fridge can be replaced. Anyone else have any experience with this? I’m sure this can’t be the first time this has happened. Stupid me!!

"I have a 240 v 50 amp outlet in my RV cover that I’ve used for years to plug my motorhome into" ---- Just how did that work?? 240 motor coach?

It works just fine even with my 2018 trailer with a 50 amp cord. The 50 amp receptacle has two hot legs, one neutral and one ground, just like a house. The trailer has two bus bars that split the power. One 120v leg feeds one bar and the other 120v leg feeds the other bar. They share the neutral and ground wires. I have my trailer plugged into it now and it works great. I got into trouble because I thought the 30 amp was wired the same way. I’m now a little smarter about RV power than I was yesterday. 😉

[cavie]

Edd505 wrote:

mxdad777 wrote:
I recently bought a 2018 Rockwood 5th wheel with a 50 amp service. I have a 240 v 50 amp outlet in my RV cover that I’ve used for years to plug my motorhome into. Since I still have my motorhome and it’s parked in the RV garage I decided to hook up my 5er temporarily to my 30 amp 240 volt welder outlet. I had no idea that RV 30 amp cords were 120v only. Long story short, after connecting my 30 to 50 adapter I sent 240 volts down one leg of the buss bar. So everything on that side of the bus bar received 240 volts while the other side received zero. My question now is what will I need to replace? My refrigerator, GFCI, rooftop A/C were all on that side. The A/C seems to be working fine, but the fridge isn’t and the GFCI is smoked. Although I’ve wired up many homes, I certainly learned something about RV’a and their wiring today. I’m hoping just the circuit board on the fridge can be replaced. Anyone else have any experience with this? I’m sure this can’t be the first time this has happened. Stupid me!!

"I have a 240 v 50 amp outlet in my RV cover that I’ve used for years to plug my motorhome into" ---- Just how did that work?? 240 motor coach?

Yes, all 50 amp RV services are 240 volts. L1 to L2. 240 volts is delivered to the RV main breaker. This main breaker is in the middle of the panel. 120 volts @50 amps to the left. 120 volts @50amps to the right. You cannot install a 2 pole breaker and get 240 volts. 240 is not accessible. Just think of it as two 50 amp 120 volt services.

[Edd505]

mxdad777 wrote:
I recently bought a 2018 Rockwood 5th wheel with a 50 amp service. I have a 240 v 50 amp outlet in my RV cover that I’ve used for years to plug my motorhome into. Since I still have my motorhome and it’s parked in the RV garage I decided to hook up my 5er temporarily to my 30 amp 240 volt welder outlet. I had no idea that RV 30 amp cords were 120v only. Long story short, after connecting my 30 to 50 adapter I sent 240 volts down one leg of the buss bar. So everything on that side of the bus bar received 240 volts while the other side received zero. My question now is what will I need to replace? My refrigerator, GFCI, rooftop A/C were all on that side. The A/C seems to be working fine, but the fridge isn’t and the GFCI is smoked. Although I’ve wired up many homes, I certainly learned something about RV’a and their wiring today. I’m hoping just the circuit board on the fridge can be replaced. Anyone else have any experience with this? I’m sure this can’t be the first time this has happened. Stupid me!!

"I have a 240 v 50 amp outlet in my RV cover that I’ve used for years to plug my motorhome into" ---- Just how did that work?? 240 motor coach?

[RoyB]

This is NO SHOCK ZONE drawings for the RV 50A and 30A service connectors...

50A SERVICE


30A/20A/15A SERVICE


This is a 30A(M) to 50A(F) Adapter - NOTE the HOT1 and HOT2 are wired together..



This is a 50A(M) to 30A(F) Adapter. NOTE only one HOT leg is used...


All diagrams are from NO SHOCK ZONE

Just passing along the info...

Roy Ken