30 vs. 50 Amp Service?

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VanForNow

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I have not yet started out on my first adventure, and electricity is still puzzling in many ways. For example, campground listings often say something like "30 and 50 amp service."


Does this mean if I use the wrong amp service I could damage the electrical system of my rig? Do I need to have an adaptor when I plug in? As I said, this is new and mysterious to me. I think my rig uses 30 amps. Anyway, I know there is a 30 amp breaker attached to the firewall, under the hood of my truck.

Enlightenment would be appreciated.
 
what kind of rig do you have again. the 30 and 50 amp service is for high power usage. you can plug a 15/30 amp RV into any with the correct adaptor. if you plug a 50amp into a 30 amp with an adaptor you must be careful. mostly the 50amp RV's are the huge class A's that have 2 AC's. highdesertranger
 
If your rig has a 30A cable, you can't plug into a 50A box. Wrong connector.
There are dogbone adapters, but if you don't need it, don't use it. Stay safe.
 
If the plug on your camper cord has the 3 prongs like this, it is 30 amp.

30 amp rv plug.jpeg

They have adapters to convert that plug for use with both 15 and 20 amp (regular house plug) and 50 amp service.  I have never needed the 50 amp to 30 amp conversion.  The 20 amp to 30 amp adapter can come in handy for a friends driveway and such where service can be extended by a regular heavy duty extension cord.  I have a 50 ft. 10 GA extension cord I use for this.  I would not use anything less than a 12 GA extension cord.  Using 20 amp service you may have to be mindful of the load you are placing on the circuit.  Using an outside plug at a friends house, I never run the air conditioner and the microwave/coffee pot or other hard hitter at the same time.

If you are new to rving, please do not connect your dump hose to the campground sewer connection and leave both valves open during your stay.  The black tank should only be dumped when at least 2/3 full and followed by a dump of the grey water tank to clean the hose.
 

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I am confused(not hard to do). do you have a camper on your truck? why do you need to plug in? more then likely the 30A breaker under your hood is for DC. the 15/30/50 amp campground hook ups are AC, two totally different systems. highdesertranger
 
Here's a picture of a typical power pedestal like you'd in an RV park.  As you can see, there is a 4 prong outlet for the 50 amp service, a 3 prong outlet for the 30 amp service, and a normal 20 amp outlet for a regular extension cord.  Each of them is controlled by their own circuit breaker, seen above them. 

Ideally, you turn on the one you want and test it to verify it's not cross-wired or missing the safety ground or something, then turn it off and plug your cord in, then turn it back on.  When you leave, you turn it off before pulling the plug.  This to prevent arcing as the plug is inserted or withdrawn.

Do a Google search on the "No Shock Zone" if you want more info on testing outlets.

As you can see, it's physically impossible to plug in to the wrong outlet by accident.  As far as getting too much current, remember that you routinely plug small appliances in to outlets that can provide 15 amps of current, and none of them draw more current than they need.
 

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The 50 amp outlet is 240v, with 120v at each side of neutral. So it has more than 3 times the power available as a 30 amp outlet. Usually there will be a 30 amp outlet beside each 50 amp one, but sometimes the 30 amp outlets are worn out so it is better to use an adapter on the 50 amp one. There should be breakers beside the outlets, turn off before plugging in or unplugging.

A 100 amp RV uses two 50 amp plugs.
 
The answers so far should give you all you need to know about campground power.
I'll just add a couple of things that I have picked up as a campground electrician as well as a guest.
If the outlet you plug into seems loose and doesn't "grip" your plug firmly .
It probably has been over heated by passing maximum power and the contacts have lost their strength and probably are damaged from arcing. The best thing to do is ask for a different site.

You will notice your plug getting hot even if you aren't using much power and it could also damage your plug.
The 15/20 amp outlets with GFCI can also wear out and need replacing , look around to find a new one before you go ask for a new site.
Also....
Some campground "maintenance" people aren't real electricians and might get defensive so just say you like the view better or too much shade as why you want to switch.....you'll catch on to this stuff with experience... Happy Camp(er)ing !
 
I think you phrased that in a way that could be confusing.  a so called 50 amp service in fact provides 100 amps, 50 from each side, but all the power going in to the RV is at 120 volts.  It does NOT provide 240 volt service, and nothing on an RV needs 240 volts.  If an electrician mistakenly mis-wires such an outlet to provide 240 volts, it will burn out everything electrical in the RV.  (It HAS happened!)

Edited to add:  Yes, if you measure between the two hot legs with a voltmeter, you will read 240 volts, but it is NOT designed to power a 240 volt appliance, and I think it just confuses newbies when we discuss this.
 
I have worked on RV's that have 220 volt stuff. The 50 amp outlet can provide 220 volts at 50 amps. It depends on how the RV is wired.
Calling 100 amps from the outlet is confusing. You can't really get 100 amps from the outlet. You can get 50 amps on one circuit and then maybe 50 amps on a different circuit if the RV wiring is configured that way.
Another confusion is the RV only uses the amps it needs. The pedestal does not push amps. Many camp grounds are screwed up, especially the lower price spread. Get a multi-meter and learn to use it. If the ground-side is bad don't plug in.
 
highdesertranger said:
I am confused(not hard to do).  do you have a camper on your truck?  why do you need to plug in?  more then likely the 30A breaker under your hood is for DC.  the 15/30/50 amp campground hook ups are AC,  two totally different systems.  highdesertranger

You're correct HDR, the 30 amp breaker is for DC. Like many newbies, I am often confused about terminology and other matters. I have a popup truck camper, by the way.
 
ok, we got that straighten out, now we are cooking. now what do you want to plug in to AC, does the camper have a cord/inlet for AC power? highdesertranger
 
highdesertranger said:
ok,  we got that straighten  out,  now we are cooking.  now what do you want to plug in to AC,  does the camper have a cord/inlet for AC power?  highdesertranger

Yes, it has an AC outlet for use in campgrounds, etc. I might need to hook up to campground AC when I need to fire up some rather heavy duty tools, for example. If I take along my Nesco dehydrator (space allowing), AC would be nice to dehydrate 6 days of meals at a time for extended camping in remote areas.
 
My 2 cents. 50's are for larger campers with dual a/c's and the like. I always prefer getting a 50 amp service and just use an adapter to fit my 30 amp cable. 30 amp service is weak for winter heat power needs. Always monitor your plugs and cable for heat and/or discoloration. You should be able to keep your hand or fingers on any area without discomfort. If not, ya got issues and don't go to sleep with that condition. Breakers are not perfect and fuses may be installed wrong. It needs monitored. 

Just for example. In summer a 30 amp will usually carry an a/c unit (roof mount or window unit), all the lights and an electric water heater or other. But if you switch on a coffee maker or vacuum, it's gonna blow the breaker. 

I ran a 30 amp camper thru 3 North Dakota winters. I could run 2 floor heaters (1500watt) , water heater, all lights on. But had to switch 1 off to make coffee or microwave a dinner. Just to give ya an idea. 

On a 50 amp, I never worried about blowing breakers. I could run all heat plus microwave and coffee maker with no problem. Ditto running any tools for short periods. ahem...usually. 

Good luck sir.
 
ok now you need to find how you plug in. you either have a cord or a male receptacle. the male receptacle will be a 15 amp looks just like your household outlets only male and not female. if you have 30 amp you will have a cord with an end on it like what's been posted for 30A. if your camper has an air conditioner it will have a 30A. highdesertranger
 
romeosierrabravo2 said:
My 2 cents. 50's are for larger campers with dual a/c's and the like. I always prefer getting a 50 amp service and just use an adapter to fit my 30 amp cable. 30 amp service is weak for winter heat power needs. Always monitor your plugs and cable for heat and/or discoloration. You should be able to keep your hand or fingers on any area without discomfort. If not, ya got issues and don't go to sleep with that condition. Breakers are not perfect and fuses may be installed wrong. It needs monitored. 

Just for example. In summer a 30 amp will usually carry an a/c unit (roof mount or window unit), all the lights and an electric water heater or other. But if you switch on a coffee maker or vacuum, it's gonna blow the breaker. 

I ran a 30 amp camper thru 3 North Dakota winters. I could run 2 floor heaters (1500watt) , water heater, all lights on. But had to switch 1 off to make coffee or microwave a dinner. Just to give ya an idea. 

On a 50 amp, I never worried about blowing breakers. I could run all heat plus microwave and coffee maker with no problem. Ditto running any tools for short periods. ahem...usually. 

Good luck sir.

RSB2:  It's that kind of "use" information that can begin to help newbies (like me) make sense of all of the electrical number soup.  Thanks for that.

On the topic of adapters ...

I'm guessing that adapters exist in both directions -- 30A cord adapted to 50A service, and 50A cord adapted to 30A service.  What I don't know is which is safe to do and why?  If anyone can shed light on that ("light" I said ;-), that would be great.

Vagabound
 
Yes, there are adapters for 30 amp to 15, 15 to 30, 30 to 50 and 50 to 30. AFAIK there is no 50 to 15 or vice versa.

I  carry a 30 to 15 so that I can plug the van in to a 30 amp circuit if that is all that's available on the post.

When I had the RV I also carried a 50 to 30 and a 15 to 30 so that I could still plug in the RV (30 amp) no matter what was available in the campground.

Once you've figured out what the camper has then you'll know which adapters to carry.

Some campgrounds will only have 15 amp service, others will have all three. If there is the right outlet, no need to use an adapter, you're not getting any more power out of it.

They are safe to use and are built for the specific purpose.

One should always test the circuit before plugging the whole camper in - I didn't  once and paid the price - blew a microwave and a tv on a badly wired pole circuit. There are testers available for this purpose. I just plugged a small 120 light in to the circuit - if it didn't blow up in my hands, it was okay..probably not the wisest thing to do but what can I say... :rolleyes:
 
One of the main reasons for carrying adapters is that sometimes you find the outlet you need isn't working correctly, but one of the other amperages is.  Maybe when you test them, you find the safety ground isn't there (maybe the wire came loose in the back of the outlet).  Or maybe when you plug in, the plug feels loose.  This leads to high resistance and the plug gets hot.  It's not unknown for the plug on the cord to melt under these conditions.

Ideally, you'll report the problem to the campground owner and request another site.  But if the campground is full, the adapters can be a lifesaver.
 
Optimistic Paranoid said:
One of the main reasons for carrying adapters is that sometimes you find the outlet you need isn't working correctly, but one of the other amperages is.  Maybe when you test them, you find the safety ground isn't there (maybe the wire came loose in the back of the outlet).  Or maybe when you plug in, the plug feels loose.  This leads to high resistance and the plug gets hot.  It's not unknown for the plug on the cord to melt under these conditions.

Ideally, you'll report the problem to the campground owner and request another site.  But if the campground is full, the adapters can be a lifesaver.

What would one of those "wisely test the plug beforehand" doo-dads look like?

Vagabound
 

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