Electrical Issue 30 vs 50 Amps

[Stutch]

Hey All!!! I have a Newmar 4018 with 50 AMP service. Just got back from a weekend where the pole was 30AMP only. I have one of those (2) 30 AMP male to (1) 50 AMP female splitter.

The coach would not charge batteries. I turned off everything except the fridge and it still did not charge the batteries. The power monitor recognized 119 volts coming in (on line 1), but it seemed there was not enough to charge the batts.

So, the inverter was using the batteries and eventually I go a LOW BATTERY fault.

I came home, plugged it into my 50 AMP outlet and all is perfect. What do you think? Is it the splitter, pole was not really 30 amps, what???

Thanks

[CA_Traveler]

I have a cheater cord and used it once even though I knew better. It was hotter than h*ll in Oregon and there were 2 30A outlets available. Da*mn expensive but we were hot!

They happen to be on different legs of the 120/240V CG service service.

And that brings up another consideration: If you have a EMS with load shedding and your 2 plugs are on the same leg of the CG split phase service then the EMS will switch to a maximum of 30A for load shedding. In other words you will have a maximum of 30A available in the rig...

[Stutch]

Thanks all. I won't throw it away but it appears use will be very limited. When I researched it, I found many people saying 30amps and possibly an additional 15 if on the pole close to each other. Made sense. No where did read that most 15s are GFCI and it would not work. It comes with a 30amp to 15 adapter so, again, it made sense.

Live and learn I guess. On my way to Walmart to get a single adapter. Thank you all.

[wa8yxm]

The dual 30 to 50 adapters are generally more trouble then they are worth, They WILL NOT WORK in most parks less you have two sites.. DO not though it away though,, Because the key word is MOST.. and I know of one park that during the slow season (July/August) only allows parking on EVERY OTHER SITE and will rent you one of those boxes. just so you can use it as designed.

I also know a few other places where it works.

But they key word again is FEW places.

Use a regular dogbone with one 30 amp plug and one 50 amp outlet

If you want you can modify your RV so one of the A/Cs (rear in my case) is a plug in model (Basically you find the wire that runs up to it, and install a plug and outlet) Where I'm stuck (50 amp site) the result is OEM.. but on a 30 amp site I pull that plug and plug into the park's 20 amp.. IF such exists. using a 12 ga cord.

[DrewE]

CA Traveler wrote:

Old-Biscuit wrote:
Only one buss bar would have been HOT so backfeeding would have required some non-normal/unusual connection .......99% not going to happen (nothing is 100% cause somebody WILL do something)

Probably less that 1%. But there could be limited voltage on the neutral due to the voltage drop under higher loads. Not much but it could be to much. And with a open ground or neutral on the connected side you could have 120V on the exposed ground or neutral.

Why take a chance with an exposed male plug on the cheater cord? Or why even use it?

That's why I posted "potentially dangerous situation".

Another possibility (not at all common in RVs) is to have some 240V device such as a heater of some sort creating a sneak path from one hot to the other (non-connected) hot. The only reason this doesn't happen is the lack of any 240V circuitry on practically all RVs.

I've seen that basic situation in a house I used to live in which had some quite questionable old wiring—which was of course fixed once I discovered it. The kitchen outlet was powered by half of the water heater circuit, which was protected with a fuses rather than a double-pole circuit breaker. When the fuse blew due to using too much power between the water heater and the kitchen appliances, I had power to the kitchen sufficient to run the digital clock in the microwave so long as the microwave or toaster or whatever wasn't running. Untangling what was going on took a bit of work.

These cheater cords oughtn't exist, IMHO.

[CA_Traveler]

Old-Biscuit wrote:
Only one buss bar would have been HOT so backfeeding would have required some non-normal/unusual connection .......99% not going to happen (nothing is 100% cause somebody WILL do something)

Probably less that 1%. But there could be limited voltage on the neutral due to the voltage drop under higher loads. Not much but it could be to much. And with a open ground or neutral on the connected side you could have 120V on the exposed ground or neutral.

Why take a chance with an exposed male plug on the cheater cord? Or why even use it?

That's why I posted "potentially dangerous situation".

[babun]

Beverley&Ken wrote:
I agree with Dale. Sounds like the adapter you have is designed to pickup two different power sources and send one to each leg of your 50 amp coach service. Get another adapter with only one 30 amp male plug, they are designed to connect each leg of your 50 amp service, you will only have a max of 30 amps available, not the 50 x2.

Ken

DING ! DING !

if your adapter looks like this,You need to get a single male 30 to a single female 50 and BOTH sides will be hot.

[Old-Biscuit]

CA Traveler wrote:
Did you really just plug in one of the male plugs? That creates a potentially dangerous situation as the other male plug could have 120V AC on it due to feedback in the rig. DON'T DO THIS.

Was the other leg plugged into a GFCI circuit as it would have tripped and caused what you have observed.

I know they sell these adapters but you should have in depth knowledge of their shortcomings and there are several. And unless you have that knowledge they my advice is to not use this adapter.

Instead go to Wallmart, etc and buy a 30A male to 50A female adapter (2 ends not 3 ends) and you will have 120V on both 50A hot legs. You will of course be limited to 30A total by the pedestal 30A CB. This is a very common and standard RV adapter.

At the same time buy a 20A male to 30A female and then you can also plug into a 20A circuit. About $20 for both adapters.

Only one buss bar would have been HOT so backfeeding would have required some non-normal/unusual connection .......99% not going to happen (nothing is 100% cause somebody WILL do something)

OP........
You stated (2) 30A male to (1) 50A female in original post now you are talking about a 30a/15a to 50a adapter :H

30/15 will not work ......usually due to 15a being GFCI along with possible power pedestal wiring issues. Same circuits/neutral etc.
Just forget about it....return it. NOT what you want!

Just get a 30A to 50A adapter.
The 30A uses a jumper inside plug to feed both 50A legs so both busses in AC Panel will be HOT

[CA_Traveler]

It's not equivalent. It connects to the hots on 2 circuits. It then connects (shorts if you like) the 2 grounds on the 2 circuits. It also connects the 2 neutrals on the 2 circuits. You may get 2 120V legs with no 240V or you may get 2 120V circuits with 240V. If a house was wired this way it would be in violation of codes for good reasons. It is now possible to overload the common ground or the common neutral because a parallel circuit has been created.

Some CGs will not allow the cheater cord as it's known.

I'll look and see if I can find some some of my prior posted knowledge on this subject.

[rgatijnet1]

Stutch wrote:
CA. Thanks. I made sure here was no feedback. I assumed one side was equivalent to a straight adapter.. Guess I was wrong.

What are the shortcomings if I use both sides, 1 30amp and the other 15 amp as it was designed to do?

Will definitely get the straight adapter.

Thanks

Both sides will work but NOT if the 15 amp outlet is a GFI outlet. Unfortunately MOST modern power poles at RV parks have GFI protected 15 amp outlets so it leaves you very few places to use that adapter. Personally I would return it to Camping World if you got it recently.

[Stutch]

CA. Thanks. I made sure here was no feedback. I assumed one side was equivalent to a straight adapter.. Guess I was wrong.

What are the shortcomings if I use both sides, 1 30amp and the other 15 amp as it was designed to do?

Will definitely get the straight adapter.

Thanks

[CA_Traveler]

Did you really just plug in one of the male plugs? That creates a potentially dangerous situation as the other male plug could have 120V AC on it due to feedback in the rig. DON'T DO THIS.

Was the other leg plugged into a GFCI circuit as it would have tripped and caused what you have observed.

I know they sell these adapters but you should have in depth knowledge of their shortcomings and there are several. And unless you have that knowledge they my advice is to not use this adapter.

Instead go to Wallmart, etc and buy a 30A male to 50A female adapter (2 ends not 3 ends) and you will have 120V on both 50A hot legs. You will of course be limited to 30A total by the pedestal 30A CB. This is a very common and standard RV adapter.

At the same time buy a 20A male to 30A female and then you can also plug into a 20A circuit. About $20 for both adapters.

[rgatijnet1]

Stutch wrote:
Old, so since 30 AMP power uses 1 leg anyway, does the plain adapter send power to both legs of the 50 AMP plug, sharing the 30 AMPS between the 2 50 AMP legs?

YES

[wolfe10]

Stutch wrote:
Old, so since 30 AMP power uses 1 leg anyway, does the plain adapter send power to both legs of the 50 AMP plug, sharing the 30 AMPS between the 2 50 AMP legs?

Correct.

The single hot on the 30 amp (male) end of the adapter connects to BOTH hots on the 50 amp (female) end.

So both sides of your coach 120 VAC breaker box are supplied. But you are limited to 30 amps total instead of 100 amps total (2X 50).

[Stutch]

Old, so since 30 AMP power uses 1 leg anyway, does the plain adapter send power to both legs of the 50 AMP plug, sharing the 30 AMPS between the 2 50 AMP legs?