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30 amps for 50 amp trailer

juancho0969
Explorer
Explorer
Hello. I am thinking of going to a campsite where the only site available is limited to 30 amps. I know I can get a converter plug and hook up, and I understand that only one of my A/Cs will work. Two questions. First, can I choose which of the two A/Cs to turn on at a given time, such that I have the living room one on during the day and the bedroom one at night, or will only of the two work at all. Second, is there any damage that I can cause to my electrical system by doing this? Thanks in advance.
28 REPLIES 28

pianotuna
Nomad II
Nomad II
My RV is 30 amp--however I added two additional shore power cords. I use plugs so I can run the converter separately--then run the RV off the inverter. I use plugs on the water heater, too. The same could be done for a 2nd air conditioner.

This gets around the gfci problem.

This modification allows me a continuous load of 5400 watts, with a peak load of 7300 watts. That, in turn, allows me to heat 100% electrically at -37 c (-34 f).

It's great for places where there are multiple 15 amp outlets on separate
breakers. Combining it with a hybrid load support inverter/charger means I can run lots of items.
Regards, Don
My ride is a 28 foot Class C, 256 watts solar, 556 amp-hours of Telcom jars, 3000 watt Magnum hybrid inverter, Sola Basic Autoformer, Microair Easy Start.

lane_hog
Explorer II
Explorer II
Why should 30A service be considered antiquated?...
  • 2019 Grand Design 29TBS (had a Winnebago and 3x Jayco owner)
  • 2016 F-150 3.5L MaxTow (had Ram 2500 CTD, Dodge Durango)
  • 130W solar and 2005 Honda EU2000i twins that just won't quit

GDS-3950BH
Explorer
Explorer
There is nothing better than being in a campground with an antiquated 30 amp electrical system, when the folks show up with the biggest rigs they could find or afford and attempt to power them up 100% with dogbones and other methods, thereby reducing voltage in the entire loop or campground. Most are idiots with no understanding whatsoever other than they need to run 3 ACs, an electric dryer, a convection oven, and more lights than on the strip in Vegas, all at the same time, just because they have them.

bucky
Explorer II
Explorer II
Lwiddis wrote:
“It is never a bad idea to monitor the voltage. If it stays above 107 all is well.”

Hughes has an excellent voltage monitor for $16 on Amazon. Ask for Howard.


Good one.
Puma 30RKSS

Bobbo
Explorer II
Explorer II
afidel wrote:
Bobbo wrote:
afidel wrote:
Yeah, I was referring to these:

Since most 20amp/30amp/50amp pedestals have a GFCI 20 amp outlet, and that adapter is GUARANTEED to trip the GFCI circuit, not only is that adapter expensive, it is also nearly worthless. It is guaranteed to trip the GFCI circuit because the same neutral wire is used for both the 20 amp outlet and the 30 amp outlet, Since the 30 amp outlet is using that neutral wire, the current on the neutral wire of the 20 amp GFCI outlet will not match the current on the 20 amp GFCI hot wire.

Sorry that I confused which adapter you were referencing earlier.


If it's a modern to-code 50A pedestal then just use the 50A 😃

I figure that's more designed for older parks with no 50A available and a user that wants to run a pair of ACs, would easily work if the second AC is a 13.5.

As long as the 20 amp outlet is NOT a GFCI outlet, which was the whole point.
Bobbo and Lin
2017 F-150 XLT 4x4 SuperCab w/Max Tow Package 3.5l EcoBoost V6
2017 Airstream Flying Cloud 23FB

afidel
Explorer II
Explorer II
Bobbo wrote:
afidel wrote:
Yeah, I was referring to these:

Since most 20amp/30amp/50amp pedestals have a GFCI 20 amp outlet, and that adapter is GUARANTEED to trip the GFCI circuit, not only is that adapter expensive, it is also nearly worthless. It is guaranteed to trip the GFCI circuit because the same neutral wire is used for both the 20 amp outlet and the 30 amp outlet, Since the 30 amp outlet is using that neutral wire, the current on the neutral wire of the 20 amp GFCI outlet will not match the current on the 20 amp GFCI hot wire.

Sorry that I confused which adapter you were referencing earlier.


If it's a modern to-code 50A pedestal then just use the 50A 😃

I figure that's more designed for older parks with no 50A available and a user that wants to run a pair of ACs, would easily work if the second AC is a 13.5.
2019 Dutchman Kodiak 293RLSL
2015 GMC 1500 Sierra 4x4 5.3 3.42 full bed
Equalizer 10k WDH

theoldwizard1
Explorer
Explorer
afidel wrote:
Yeah, I was referring to these:

I have never seen an adapter like that ! It may not give the desired results (30A on one leg and 20A on the other) as some campgrounds may use the same "leg" for both the 20A and 30A circuit.

CA_Traveler
Explorer III
Explorer III
My adapter has been used once but I avoid it's usage due to the safety concerns.

But in making a reservation this summer a CG suggested I use the 30/30/50 apapter to get more power. Clearly they are unaware of the safety issues and I don't plan to use it. Hopefully that area will not be hot.

Another factor is that as a user you have no idea how the pedestals are wired and the wiring can make for a successful usage even though the safety concerns remain.
2009 Holiday Rambler 42' Scepter with ISL 400 Cummins
750 Watts Solar Morningstar MPPT 60 Controller
2014 Grand Cherokee Overland

Bob

Bobbo
Explorer II
Explorer II
afidel wrote:
Yeah, I was referring to these:

Since most 20amp/30amp/50amp pedestals have a GFCI 20 amp outlet, and that adapter is GUARANTEED to trip the GFCI circuit, not only is that adapter expensive, it is also nearly worthless. It is guaranteed to trip the GFCI circuit because the same neutral wire is used for both the 20 amp outlet and the 30 amp outlet, Since the 30 amp outlet is using that neutral wire, the current on the neutral wire of the 20 amp GFCI outlet will not match the current on the 20 amp GFCI hot wire.

Sorry that I confused which adapter you were referencing earlier.
Bobbo and Lin
2017 F-150 XLT 4x4 SuperCab w/Max Tow Package 3.5l EcoBoost V6
2017 Airstream Flying Cloud 23FB

CA_Traveler
Explorer III
Explorer III
Be aware that some CGs won't allow that adapter which is justified for both usage and safety.

But get one with 2x 30A male plugs and you can always adapt one plug to 20A. This adapter can supply 120V 30A + 30A or 120V 30A + 20A. This is less than the standard 120/240V 50A plug.
2009 Holiday Rambler 42' Scepter with ISL 400 Cummins
750 Watts Solar Morningstar MPPT 60 Controller
2014 Grand Cherokee Overland

Bob

valhalla360
Nomad
Nomad
SDcampowneroperator wrote:
30a = 3600w. 50a = 12600 w potential Power mizering is a lesson we learned long ago.
Turn fridge, furnace , cold water heater to propane. You now have most wattage available except for the small drain for lights tv and such.
What this means is you can run 2 power hungry devices at a time, like 1a/c and hair dryer, Toaster and coffee pot, and so on.
Not 3 .
A/cs typically draw 12-15 a on start, run at 10-11a Thats yes you can run 2 a/cs on 30a IF you have reduced all other load.
If an a/c runs at 12a usually less, thats 1500watts. 2 is 3000watts leaving 600 w for incidentals. just fine.
You cant hurt anything just trip a breaker that reminds you you forgot to shut something off before you tirned on something else.
Learn to proactively manage your load Many years on construction sites or on a friends back yard and we have run 1 a/c on 15 amp many times.


30 amp is a nominal rating. For continuous loads like air/con, you are limited to 80% of the rating or about 2900w. If you are lucky, an extra load will trip the breaker and be annoying enough that you stop it. More likely, you hang just below the level that will trip the breaker and the cord will overheat.

Of course, this also assumes you have a real 120v. At many parks, you might be closer to 110v, which results in 2650w available for continuous loads.

Problem is you are slowly cooking your electrical system doing this. Because it's slow, you will see people claim they have done it without problems.
Tammy & Mike
Ford F250 V10
2021 Gray Wolf
Gemini Catamaran 34'
Full Time spliting time between boat and RV

rlw999
Explorer
Explorer
starlord wrote:
OK,first, I have 50 amp service and have stayed at places without 50 amp available. It is possible to use an adapter that runs to both 30 amp service AND 15/20 amp service giving you the ability to run everything you normally would. As stated, I have had to do this multiple time with no problems what so ever.


50A service isn't the same as 30A + 20A service. It's more like 50A + 50A service.

50A service gives you two 50A legs, 30A + 20A would give you at most 30A on one leg and 20A on the other, so you may still trip the breaker if you run the A/C and electric cooktop(s) at the same time. Or even an A/C unit alone can trip a 15A breaker.

Plus they may tap the 15/20A downstream of the 30A breaker, so even if you plug into both, so you may still only get 30A of current.

And 50A RV service is normally (but not always!) split phase, so you can get 240V across the hot legs. I've seen 240VAC dryers in some of the bigger class A's, so even with a 2 plug adapter, you may not be able to run "everything".

And one other drawback -- it won't work when the 15/20A outlet is GFCI protected, it will trip the GFCI.

rhagfo
Explorer
Explorer
pianotuna wrote:
It is never a bad idea to monitor the voltage. If it stays above 107 all is well.


This is why having an EMS is important, that not only gives voltage, but also amps used.
Russ & Paula the Beagle Belle.
2016 Ram Laramie 3500 Aisin DRW 4X4 Long bed.
2005 Copper Canyon 293 FWSLS, 32' GVWR 12,360#

"Visit and Enjoy Oregon State Parks"

afidel
Explorer II
Explorer II
Yeah, I was referring to these:
2019 Dutchman Kodiak 293RLSL
2015 GMC 1500 Sierra 4x4 5.3 3.42 full bed
Equalizer 10k WDH