What is 30-30 service?

[Colelaus]

I'm checking out Unicoi State Park in Georgia and they list sites with 30-50 service but also list 30-30. I thought this may be a misprint but in the FAQ they make note that some sites are 30-30 and others are 30-50 and to pick accordingly.

What is 30-30 service? For a 50amp rig, would I just consider this to be a hookup to a 30amp service?

TIA.

[Tony Ramirez]

Maybe 30-50 is a 30 A & a 50A outlet at the site, a 30-30 is two 30A outlets. Just guessing.

[twinboat]

They make a Y cable with 2 30 amp plugs and a 50 amp outlet.
That will work on a 30/30 site.

[Colelaus]

Originally Posted by twinboat

They make a Y cable with 2 30 amp plugs and a 50 amp outlet.
That will work on a 30/30 site.

Great... one more cable to purchase!

However, a quick search of amazon and google are yielding no hits on an adapter of this type. Would you know what a good search term for this adapter may be or who may sell it?

[d23haynes57]

https://www.amazon.com/dp/B07R45LLXB...WxfdGhlbWF0aWM

https://www.amazon.com/dp/B09YHLPGBK...mc_p_m_5_i_atc

[Vato]

Call and ask...

[Old Scout]

"Guessing" 30-30 is two 30 amp plugs on a single post--not phased. Modern campgrounds usually have 30-50 [one 30 amp and one 50 amp] on a post. The 50 amp is phased to prevent overloading the neutral leg. Most Rvs dont have 220/240 appliances so phased only protects the neutral. 30-amp service is limited to a load of 30 amps while 50-amp service provides 100 total amps. 50-amp service RVs can use either 50 or 30-amp service but with 30 amps, you must manage your amp load, eg, usually only one AC. Most, newer Rvs have surge protectors or energy mgt systems--they dont always "like" the old y-split two 30 to one 50-amp adapter. Doubt if you can find one these days.

[Sweetbriar]

The 30-30 are double buddy sites 24' wide to accommodate two camping units on the same site.

From the CG reservation page -

"Campsite #2 is a Double Buddy Site with two 30’ back-in power and water gravel sites located in Little Brook Spur. This site is 36’ long and 24’ wide and can accommodate 30 - 30 AMP hook up. Each site is equipped with a picnic table and a fire ring with a grill top.."

Sounds a bit like camping in Myrtle Beach when your awning just about touches your neighbor's rig. Sharing 24' doesn't leave much room when you're 9' wide.

[Gary RVRoamer]

What Sweetbriar says. Georgia offers "buddy sites" at many of their state parks, usually equipped with two 30A outlets. Works well enough for one 50A RV too, if you have the Y-adapter that was mentioned. I used to book them when I hosted rallys there, since the buddy sites are huge and thus great for group activities.

[hypoxia]

Originally Posted by twinboat

They make a Y cable with 2 30 amp plugs and a 50 amp outlet.
That will work on a 30/30 site.

I use a Y cable fairly often. I use a voltmeter to make sure there is 240VAC across the 50A outlet and 120VAC from each hot to the neutral & ground before I plug the coach in. If both 30A outlets are on the same phase you will not read 240VAC and the Y cable will not work. My stove is 240VAC so it comes in handy.

[Colelaus]

Mystery solved!

Unicoi does have 30-30 buddy sites but the one I selected was not one of them. I called the state park, and it turns out that many of their full-hookup single sites were labeled incorrectly as 30-30 on the website. She submitted a ticket and hopefully that will be corrected in the next couple of days.

Thanks for the education!

[powercat_ras]

FYI, if you "Y" two 30A NEMA TT-30 into a 50A NEMA 14-50 and the TT-30 are on the same power phase then you risk slightly overloading your shore cable as the current going down the neutral wire will be the sum of the two line wire currents. Worst case 60 amps and the wire is sized to carry 50 amps without overheating.

As was said in a prior post you can measure between the right and left slots on the NEMA 14-50 with a voltmeter and if there is 240 VAC between them the two line wires are opposite phase and there is no risk. If you measure no 0 VAC between them they are the same phase. In this case just make sure you are using less than a total of 50 amps for all the loads in the RV.

Also, in many RVs with a Power Management System if they see the two line wires are the same phase it will display that you are connected to 30 amp shore power and will manage power to limit to 30 amps max draw even though you actually have 60 fed from the breakers, and 50 ususable without overheating the neutral wire.

[ViperJD]

Randy, I don't understand why you think 60 amps will overheat the 50 amp cable. Our 2-phased 50 amps is 50 to each leg, or 100 amps total at 120 volts. Using a splice to get two 30 amps, means each leg can only pull 30 amps...so you are 40 amps lower that normal 2-phase 50 amp service.

Am I missing something?

[twinboat]

Originally Posted by powercat_ras

FYI, if you "Y" two 30A NEMA TT-30 into a 50A NEMA 14-50 and the TT-30 are on the same power phase then you risk slightly overloading your shore cable as the current going down the neutral wire will be the sum of the two line wire currents. Worst case 60 amps and the wire is sized to carry 50 amps without overheating.

As was said in a prior post you can measure between the right and left slots on the NEMA 14-50 with a voltmeter and if there is 240 VAC between them the two line wires are opposite phase and there is no risk. If you measure no 0 VAC between them they are the same phase. In this case just make sure you are using less than a total of 50 amps for all the loads in the RV.

Also, in many RVs with a Power Management System if they see the two line wires are the same phase it will display that you are connected to 30 amp shore power and will manage power to limit to 30 amps max draw even though you actually have 60 fed from the breakers, and 50 ususable without overheating the neutral wire.

The wire is rated for 60 amps and the 50 amp auto transfer switch has a 60 amp rating on the neutral contacts. Look one up.