30 amp to 50 amp

[wmtire]

Originally Posted by Paul GA

Any dryer plug wired in the last 20 years must have ground separate from the neutral. 4 prongs he's good to go, 3 he's not.

True, but Rivnut said previously that it appeared the 50 amp female to 30 amp male adapter would work...which means the dryer plug is 3 pronged (no separate ground)...and the prong configuration is wrong to use any such adapter. Based on his statement, then this is the assumption we should work from.

Originally Posted by Rivnut

Can we talk about getting 30 or 50 amps from the dryer plug, my son has no spare circuits or anything else to supply us with power to the trailer when we visit. Looks like the second picture dogbone would fit the dryer plug. Can I do this???
thanks
Rivnut

Originally Posted by wmtire

They make adapters to go both ways. The 50 amp male to 30 amp female adapter just terminates the L2 leg inside the adapter so there is no second 120 volt leg (L2), which a 30 amp RV doesn't need.



12" Adapter 50 Amp Male to 30 Amp Female Dogbone Adapter



The 30 amp male to 50 amp female jumps the L1 leg over onto the L2 side, to provide power to both legs inside a 50 amp RV, albeit you are limited to 30 amps total power between both legs.

[Herk7769]

Originally Posted by Paul GA

so are 50 amp rv plugs... what's the difference?

There is no Neutral (white) wire in a 240VAC dryer outlet that is required to split the 240 into two 120 volt circuits used in the 50 amp RV plug.

A 240VAC dryer outlet has only two "HOT" wires; one red and one black and the bare safety ground.

The 50 amp RV outlet requires 4 wires; two "HOT" wires (one red and one black), the white Neutral (for the 120 volt "return path") and the bare safety ground.

[WY Husker Fan]

Actually if a 3 wire dryer circuit is correctly configured it has two hots and a neutral with no equipment ground. The motor in a dryer is 120volt and the heating element is 240 volt. The code used to allow this configuration for ranges and dryers. The frame of the machine was then bonded to the neutral to ground it. No longer allowed for new installations. If the OP's receptacle is 3 wire I would not use it. If 4 wire, the receptacle will not match a standard 50 to 30 dog bone but a adapter could be made up that would work fine if done correctly.

[wmtire]

Lou, I know it's easy to confuse all the different combinations and such, but it may be the welding service you are talking about that has no neutral, and not the dryer service as WY Husker Fan accurately explained above.

From the RV electric link:

Welder Service is not the same as the OLD Appliance Service. Both are 3-wires but the OLD Appliance use 2 Hot and Neutral.... the Welder use 2 Hot and Ground. NEMA 6-30R or 6-50R

In a straight 240-volt circuit like an electric hot water heater or a welder there is no need for a neutral return. All of the energy is absorbed and used up by the elements and the welder. The Ground is VERY important for a welder to work. In case of a short in the welder's transformer/rectifier the current would quickly go straight to ground and hopefully trip out the 30 or the 50 amp breaker from overload.


The above straight 240-volt would also work on the electric stove and dryer except they need the 240-volt for the dryer and stove's heating elements and the 120-volt to run the dryer motor and the controls on the stove so they need the neutral wire. (See the Appliance Service on the left)

[Paul GA]

Originally Posted by Herk7769

There is no Neutral (white) wire in a 240VAC dryer outlet that is required to split the 240 into two 120 volt circuits used in the 50 amp RV plug.

A 240VAC dryer outlet has only two "HOT" wires; one red and one black and the bare safety ground.

The 50 amp RV outlet requires 4 wires; two "HOT" wires (one red and one black), the white Neutral (for the 120 volt "return path") and the bare safety ground.

A 4-prong dryer outlet in a house built mid nineties and after does indeed have a separate neutral. A 3-prong (pre-nineties) does not.

[Herk7769]

Have never lived in a house that was not over 50 years old

Thanks for the update.

[Paul GA]

Originally Posted by Herk7769

Have never lived in a house that was not over 50 years old

Thanks for the update.

You've got a better built home than mine built in 2000 I'm sure!

[Rivnut]

Originally Posted by elrand

It's fine to use the 50 to 30 adapter. Your main inside your trailer is rated for 30 amps so that's all it will allow to flow. so everything inside your trailer is still protected and you said you had a surge protector so that will take care of any spikes that may come down the line.

Speaking as an electrician. The guy you meet in the store might not of understood that this is a common safe practice since our rigs have an additional breaker inside that will protect our trailer

Yes you are safe with this practice

Can I get a dryer to rv dogbone??????

[TURBS]

Originally Posted by Rivnut

Can I get a dryer to rv dogbone??????

HA! your kidding right?

Sent from my SCH-R530U using Tapatalk

[Rivnut]

Thanks to WMTIRE and Paul, I will get an electricial to make an adapter box with the neutral. I made one that worked, and was lucky now one got hurt, but then I had it isolated from touch. We just have to adpt something or borrow from some circuit as his house is from the 50's in Memphis, and there is no spare anything. Thanks to all for the help. I am not familiar with the house hold circuits for sure, that's why I ask.
Rivnut