Help with power for 50 amp service plugging into 30 & 15 amp with adapter

[Waterops1]

Not familiar with this adapter being talked about but if it is not to be used in GFCI (protected?) receptacles that is an issue. Duplex receptacles in CG pedestals I have seen have GF C/B. As other posters have said it is quite possible to get by with less power but at the sacrifice of A/C.

[randymoore5]

Thanks to everyone for the information. I ordered a standard 50 to 30 adapter and will monitor usage with the EMS. I certainly have a much better understanding of the power at the pedestal and how the adapter works.

[wmtire]

Originally Posted by randymoore5

Thanks to everyone for the information. I ordered a standard 50 to 30 adapter and will monitor usage with the EMS. I certainly have a much better understanding of the power at the pedestal and how the adapter works.

Aw now, I was wanting to use the diagrams and schematics. You're no fun.

[jacknife]

Just get a Dog bone 50 to 30 adapter . Still use your surge protector if not built in . 30 works fine many trailers and class C motor homes with one AC are still made with 30 setups.

[babock]

Originally Posted by jacknife

Just get a Dog bone 50 to 30 adapter . Still use your surge protector if not built in . 30 works fine many trailers and class C motor homes with one AC are still made with 30 setups.

Yes...read post #22.

[B and B]

Originally Posted by Flybob

Be aware that most campgrounds that have 30A service ( a 30A RV plug and a 15/20A household outlet) tie three sites into a 100A breaker upstream in a locked panel. Using more than 30A from a pedestal when the other two sites are using 30A will trip the 100A breaker. This usually needs to be reset by park personnel and can take some time to get done. This will not make you friends at the other two sites.

Hello,

This is incorrect and against the NEC. The branch circuit wire size and ampacity must match the source.

[johntaylor]

Originally Posted by bobsteele

A standard 50 to 30 adapter puts both 50A legs onto the 30A feed.

No it doesn't. The 50A/30A adapter draws from one leg of the 50A supply. The two legs of the 50A supply are 180 degrees out of phase. (120V between each hot leg and neutral, 240V between the two hot legs.) Connecting them together would short them out.

[wmtire]

Originally Posted by johntaylor

No it doesn't. The 50A/30A adapter draws from one leg of the 50A supply. The two legs of the 50A supply are 180 degrees out of phase. (120V between each hot leg and neutral, 240V between the two hot legs.) Connecting them together would short them out.

John, Bobsteele is correct and the adapter actually does connect the one L1 from a 30 amp outlet and then jumps it over to the L2...where both the RV's L1 and L2 are being fed by the ONLY L1 that there is in a 30 amp outlet. The RV's L1 and L2 will both be powered, but are sharing the 30 amps for everything. You will be limited to a grand total of 30 amps.

This thread is discussing/talking about adapting a 50 amp RV to a 30 amp outlet. The OP has a 50 amp RV and is asking about going to campgrounds with only 30 and 15 amp outlets. Here is a diagram of using an adapter to connect a split phase 50 amp RV to a 30 amp outlet. Note the jumper:





What you are thinking of is completely opposite of when you are trying to connect a 30 amp RV to a 50 amp outlet ...and thus only use one leg of the 50 amp service using the adapter below. It can get confusing.



Hey!! I did get to use some of my diagrams. LOL

[randymoore5]

Originally Posted by wmtire

John, Bobsteele is correct and the adapter actually does connect the one L1 from a 30 amp outlet and then jumps it over to the L2...where both the RV's L1 and L2 are being fed by the ONLY L1 that there is in a 30 amp outlet. The RV's L1 and L2 will both be powered, but are sharing the 30 amps for everything. You will be limited to a grand total of 30 amps.

This thread is discussing/talking about adapting a 50 amp RV to a 30 amp outlet. The OP has a 50 amp RV and is asking about going to campgrounds with only 30 and 15 amp outlets. Here is a diagram of using an adapter to connect a split phase 50 amp RV to a 30 amp outlet. Note the jumper:





What you are thinking of is completely opposite of when you are trying to connect a 30 amp RV to a 50 amp outlet ...and thus only use one leg of the 50 amp service using the adapter below. It can get confusing.



Hey!! I did get to use some of my diagrams. LOL

Very nice. Glad you got to use those.

[DouglasReid]

Originally Posted by randymoore5

I’m not an electrician so excuse my ignorance. The 30 amp service is 2 15 amp services combined is that correct? If that is true is it really even possible for this device to supply 45 amps.

NO, It is simply one single 30 amp hot wire (with a ground and neutral of course)

[Arctic Wolf]

So the 50 amp is a 240 volt service on two legs, just like normal house wiring?

[FFred]

"So the 50 amp is a 240 volt service on two legs, just like normal house "wiring?

YES

[CedarCreekWoody]

Originally Posted by Arctic Wolf

So the 50 amp is a 240 volt service on two legs, just like normal hours wiring?

Yes, BUT the RV does not use it as 240 volts, it uses it as two separate legs with 120 volt each.

[Arctic Wolf]

Originally Posted by CedarCreekWoody

Yes, BUT the RV does not use it as 240 volts, it uses it as two separate legs with 120 volt each.

Got it, but as far as wiring a pedestal at my house, it's just a 240 circuit?
I thought I read a horror story on here recently about that... Maybe he was 30 amp

[wmtire]

Originally Posted by Arctic Wolf

So the 50 amp is a 240 volt service on two legs, just like normal hours wiring?

Originally Posted by FFred

"So the 50 amp is a 240 volt service on two legs, just like normal house "wiring?

YES

Originally Posted by CedarCreekWoody

Yes, BUT the RV does not use it as 240 volts, it uses it as two separate legs with 120 volt each.

Yeppers. More diagrams (I love showing these )

[wmtire]

Originally Posted by Arctic Wolf

Got it, but as far as wiring a pedestal at my house, it's just a 240 circuit?
I thought I read a horror story on here recently about that... Maybe he was 30 amp

Yes, about all the 240 volt miswires concern a 30 amp outlet and a double pole breaker... and thus contained to 30 amp RV's.

However, we have had at least one instance I personally know of on these forums, where a member connected his 50 amp RV into a miswired 30 amp outlet utilizing an adapter, thus causing much damage.

You NEVER want 240 volts on any 30 amp RV outlet...ever, period.

The readings on RV friendly receptacles.

For the 50-amp 120/240-volt 3 pole 4 wire grounding service

For the 30-amp 120-volt 2 pole 3 wire RV service

14-50R

The voltage between Y and X should be 240-Volt, X and W 120-Volt, Y and W 120-Volt, X and G 120-volt, Y and G 120-volt, W and G 0-Volt

TT-30R

The voltage between the Hot lead at 7 o'clock and W 120-volt, Hot lead and G 120-volt, W and G 0-volt