50 amp vs 30 amp?

[Leismom]

Last min reservation this weekend, I was able to get 30 amp site. I have a Georgetown, 50 amp. Will I be able to use all the normal appliances or will I be limited on what I can use at the same time. Advice please....thanks

[wmtire]

Originally Posted by Leismom

Last min reservation this weekend, I was able to get 30 amp site. I have a Georgetown, 50 amp. Will I be able to use all the normal appliances or will I be limited on what I can use at the same time. Advice please....thanks

They will be all powered via the adapter but you are going to be limited to what you can use at the same time.

Simply put, when using a 120/240 volt 50 amp split phase service, your RV has TWO 50 amp legs powering it, each at 50 amps for a grand total of 100 amps of potential power.

A 30 amp single phase service has ONE leg at 30 amps for a grand total of 30 amps of potential power.

So, when you have to use an adapter and plug into the 30 amp service, you are actually moving from 100 amps of potential power, to 30 amps....and cannot use everything at the same time as you could when plugged into a 50 amp outlet. You need to remember that your power potential has dropped by over two/thirds when using a 30 amp outlet.

This link explains the differences and the last paragraph explains the adapter you are using:


Electrical Tutorial - Chapter 3 - 30 Amp versus 50 Amp

[SeaDog]

You will be somewhat limited, your coach is designed for 50 amps to run all your equipment. What will happen is if you bring on to many appliances you may trip the 30 amp breaker. Make sure you have the 30 to 50 amp adapter before you leave.

[spock123]

Run your hot water heater on propane and if you have a RV refrigerator run that on gas. I would say than half of all campers have only 30amps and they get along fine


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[kfd82]

I'm still new to all this, but I was told I could run everything except my 2nd air conditioner.

May not be able to run the microwave and a hair dryer and the AC all at once, but you should be able to run everything you need.

[ShermanD]

Originally Posted by kfd82

I'm still new to all this, but I was told I could run everything except my 2nd air conditioner.

May not be able to run the microwave and a hair dryer and the AC all at once, but you should be able to run everything you need.

In a perfect world, unfortunately most campgrounds do not have perfect nor adequate services for the number of sites they have.

the electrical services per code is NOT required to handle the full load capacity of all the outlets. Most parks will be using all those outlets on a busy weekend, therefore your voltage will be on the low end causing your amperage to be on the high end.

You don't want to use the micro, water heater, a hair dryer and the Air conditioner at the same time. The starting load on the Air conditioner alone will be 20+ amps, water heater - 12 amps, 1000 watt microwave - 9 amps. 1500 watt hair dryer - 12 amps.

Then there is the power inverter that is running all the time that uses a share of the 30 amp capacity.

The only way you will be able to tell what you can run at the same time is by trial and error and most likely will not be the same at every location.

The DW found out the hard way a couple weekends ago. The campground was near capacity. She was running the microwave when the Air conditioner fired up causing our 30 Amp main to trip.

FWI those main breakers in your electrical panel get weaker with each time they trip and after a while will either not trip or trip well below their rated capacity... to low is safe, too high is dangerous and can lead to fires.

[fljl]

Had same issue, lites, micro and AC would trip a 30 amp. Could have been weak breaker. 50 will do two AC and everything else.

[dwayneb236]

A few weeks ago we went to a campground that only had 30 amps available. We tried it for about an hour. Got fed up with the power shutting down when ever we tried to run a couple of things and one ac just not doing it. We're spoiled with our 50 amp system and running whatever we want.
We ended up packing it in and moving to another campground that was about an hour north. 50 amp and ran whatever we wanted. Just not exactly where we wanted to be. But hey, we were camping right?


The first camp was pretty busy as well and with older looking boxes.

[Kenny kustom]

Originally Posted by dwayneb236

A few weeks ago we went to a campground that only had 30 amps available. We tried it for about an hour. Got fed up with the power shutting down when ever we tried to run a couple of things and one ac just not doing it. We're spoiled with our 50 amp system and running whatever we want.
We ended up packing it in and moving to another campground that was about an hour north. 50 amp and ran whatever we wanted. Just not exactly where we wanted to be. But hey, we were camping right?


The first camp was pretty busy as well and with older looking boxes.

We are in the same boat.
Except, no option to move to 50A.

That's why I put in a hybrid inverter.
I can run whatever I want off 30A.
Well worth the cost of the inverter.


2016 Sabre 36QBOK
2015 Ram 3500 CUMMINS
Bring Back The Search!

[ChateauV10]

Originally Posted by Kenny kustom

We are in the same boat.
Except, no option to move to 50A.

That's why I put in a hybrid inverter.
I can run whatever I want off 30A.
Well worth the cost of the inverter.


2016 Sabre 36QBOK
2015 Ram 3500 CUMMINS
Bring Back The Search!

Kenny, what is a "hybrid inverter"? What Make & model did you put in?

[Steve29rlx]

Originally Posted by wmtire

They will be all powered via the adapter but you are going to be limited to what you can use at the same time.

Simply put, when using a 120/240 volt 50 amp split phase service, your RV has TWO 50 amp legs powering it, each at 50 amps for a grand total of 100 amps of potential power.

A 30 amp single phase service has ONE leg at 30 amps for a grand total of 30 amps of potential power.

So, when you have to use an adapter and plug into the 30 amp service, you are actually moving from 100 amps of potential power, to 30 amps....and cannot use everything at the same time as you could when plugged into a 50 amp outlet. You need to remember that your power potential has dropped by over two/thirds when using a 30 amp outlet.

This link explains the differences and the last paragraph explains the adapter you are using:


Electrical Tutorial - Chapter 3 - 30 Amp versus 50 Amp

How is 100 amps possible with a 50 amp breaker? If you tried to se 100 amps wouldn't the breaker trip?

[wmtire]

Originally Posted by Steve29rlx

How is 100 amps possible with a 50 amp breaker? If you tried to se 100 amps wouldn't the breaker trip?

A 120/240 volt split phase service is really simple once you understand it, but it can take a bit to get your head wrapped around it. The biggest confusion is people thinking that 120/240 split phase works like 120 volt single phase.....which it doesn't.

The main thing to understand is that a 50 amp service is 50 amps at 240 volts or 100 amps at 120 volts. Both produce 12000 watts. Watts= amps X volts

A double pole 50 amp circuit breaker grabs 50 amps from one pole/leg (L1) at 120 volts and another 50 amps from another pole/leg (L2) at 120 volts.

To get 240 volts, you have to have an item connected to both L1 and L2.

The RV doesn't have items connected to both L1 and L2...but instead uses the L1 and L2 separately, so L1 provides 50 amps at 120 volts and L2 provides another 50 amps at 120 volts....... for a total of 100 amps at 120 volts.

Now the L1 and L2 share a common neutral wire (you have to have a neutral when using 120 volts), which is also only rated to carry 50 amps. However, the way the split phase service works is called load balancing as power shuttles back and forth between L1 and L2. The neutral only carries the imbalance.

If you are using 45 amps on L1 and 40 amps on L2...then the imbalance is 5 amps, and this is what the neutral wire carries.

At the extreme, say you are using the max on L1 of 50 amps (as per its circuit breaker max). Then say you are using 0 amps on L2. Then the neutral carries the imbalance of 50 amps (which it is rated for). If something were to happen on either L1 or the L2 and the amps were exceeded on either, then since a double pole breaker is in essence two breakers tied together, if one side trips, then the other side has to trip too. This also protects the shared neutral wire so neither L1 or L2 can make it carry any possible imbalance of over 50 amps.

It's explained a lot better in this link. it takes a little to wrap your head around it, but you will.

Electrical Tutorial - Chapter 3 - 30 Amp versus 50 Amp

More reading;

http://www.rv-motorhome-answers.com/AC-Electricity.html

http://www.myrv.us/electric/

http://www.nojolt.com/Understanding_...circuits.shtml

[Kenny kustom]

Originally Posted by ChateauV10

Kenny, what is a "hybrid inverter"? What Make & model did you put in?

Magnum msh3012m

It's a 3k watt inverter than can use battery power to support the shore power. I split most of the rig ac circuits into the sub panel.
I tell the inverter to use 14 amps from the shore power. Any more draw, and the inverter will pull from the batteries.

I also run both fridges on electric while on the road.



I did some testing the other day.
Ran the front ac right off the batteries.

After an hour, the batteries were still at 85% SOC.


2016 Sabre 36QBOK
2015 Ram 3500 CUMMINS
Bring Back The Search!

[Evereddie]

I think 50 amp service should be called 100 amp service. That is what it is and it would eliminate much of the confusion. Ya, it's split between 2 legs but it is still 100 amps for the rig.

[5picker]

Originally Posted by Evereddie

I think 50 amp service should be called 100 amp service. That is what it is and it would eliminate much of the confusion. Ya, it's split between 2 legs but it is still 100 amps for the rig.

I disagree. It is NOT a 100 amp service. Any draw of more than 50 amps per phase, will trip the breaker. A more appropriate name might be 'Dual 50 Amp' but not 100 amp.

[Evereddie]

Originally Posted by 5picker

I disagree....

Here, someone always will.
Let's try this,...the sky is blue.

[B and B]

If North America abandoned 120 v and went 240 volt for RV's the anacondas we have to carry would have the size. Just 100 amps at 240 volt or 30 amp 120.

[5picker]

Originally Posted by Evereddie

Here, someone always will.
Let's try this,...the sky is blue.

Nope... not today. Cloudy & grey.

[ShermanD]

Originally Posted by 5picker

I disagree. It is NOT a 100 amp service. Any draw of more than 50 amps per phase, will trip the breaker. A more appropriate name might be 'Dual 50 Amp' but not 100 amp.

X2

A 100 amp 120/240 volt residential service provides 100 amps of 120 volt power on each of two hot legs with the neutral wire capable of carrying an unbalanced load of 100 amps.

A 50 amp 120/240 volt RV service provides 50 amps of 120 volt power on each of two hot legs with the neutral wire capable of carrying an unbalanced load of 50 amps.

A 30 amp 120 volt RV service provides 30 amps of 120 volts power on one hot leg with the neutral wire capable of carrying the entire load of 30 amps.

A 20 amp 120 volt RV service, used on older popups and ?, provides 20 amps of power on one hot leg with the neutral wire capable of carrying the entire 20 amp load.

It takes two hot wires with a shared neutral in order to have an unbalanced load.

It is my understanding that most RV's do not use any 240 volt appliances, although there is no reason they couldn't. An instant hot water heater would draw half the amps if wired straight 220. Unfortunately the instant hot water heater would be useless without a 50 amp 120/240 volt shore power or generator, which is probably the reasoning for wiring everything 120 volts.
45 year member IBEW retired

[325BH]

Originally Posted by 5picker

I disagree. It is NOT a 100 amp service. Any draw of more than 50 amps per phase, will trip the breaker. A more appropriate name might be 'Dual 50 Amp' but not 100 amp.

You are correct, more than 50 amps on either leg and the double breaker will trip. You can however pull 50 amps on each leg, which is the 100 amps.




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