50 amp service question

[scanzel]

Are the 50 amp connections at rv parks a 50 amp/220v connection or 50amp/120v  connection? I think I worded this correctly. 25amps on each leg of the 50amp/220v or a straight 50 amps at 120 volts? How is everyone setting up their conversions for 50amp or 30 amp?

[TomCat]

Steve,

Although there should be a firm standard, you're liable to find any configuration of 15a, 20a, 30a, 50a out on the road.
My coach is wired for 50a on each of two 120v legs.
This gives a total of 12,000 watts.
I think most other coaches are this way as well.

Jay
87 SaftLiner

[Kwajdiver]

Steve,

All the parks I have been in the last year, (I'm a fulltimer) have had 50a/120v.   I understand you will find a few parks that only have 30a/120v, so always be prepared for that.

Hope this helps,

Bill

[Nick Badame Refrig/ACC]

Hi Steve,

I think the answer you are looking for is  two 50a legs of 115v but  "230v between them" is the standard.. = 50 amps on each leg!

Most are wireing their coaches for 50a.

Always check your park post for proper phase and voltage.

Good Luck
Nick-

[belfert]

Does the electrical code for RVs specify that 50 service should be 230 volts across the hot legs?  I've heard plenty of stories from S&S and conversion owners of 50 amp service that is either supplied with both hot legs on the same phase or the total of the two hot legs is 50 amps and not 100 amps like it should be.

A typical S&S motorhome won't have anything that is 230 volt so both hots on the same phase won't hurt anything except perhaps overload the neutral.

My electrical conundrum right now is if I should install an electric cooktop and what voltage.  230 volt cooktops are certainly easier to find (and cheaper), but then I have to worry more about my input power or run the generator to use my cooktop.  Using 230 volts also means my inverter could not power the cooktop, but my batteries couldn't handle the load for long anyhow.

[TomC]

My generator and circuts are wired straight 120vac.  So I have 10,000 watts of straight 120v, and can only use one side of the 50amp plug which still gives me 6,000 watts of power.  I really like this setup since I NEVER have to think about balancing loads between the two legs of input and the generator is always balanced.  I sometimes have to time my useage of the two water heaters, but ususally just heat one at a time and otherwise everything works well.  Good Luck, TomC

[HB of CJ]

Wow!!...I understand that you are writing/speaking English, but I have no idea what you are talking about.  Obviously my knowledge/education on the safety/understanding of basic electrical circuits leaves a lot to be desired.  I need to learn a whole lot more about this.  Full Speed Ahead!!!  He he he.  Happy New Year!! 

[Nick Badame Refrig/ACC]

Hi HB,

I'm going to try and make this a little more clear for you.

Nick-

[Nick Badame Refrig/ACC]

 We will see if theese pics upload??

[Kristinsgrandpa]

Nick, your little wiring diagram is priceless, nice job.

Belfert, Yes the National Electric Code does require 50 amp services to be 120/240 V, give or take a few volts.

Article 551.71 states that at least 20 percent of the RV sites have to have  50 AMP 125/250 volt receptacles. (14-50 R)

That said, there are 7 or 8 states that haven't adopted the NEC and you are at the mercy of whoever designed/wired the park.

Right now the NEC people are trying to come up with a higher ampacity receptacle/plug set because more and more big rigs need more power.

One of the biggest problems is that in the remaining states, that have adopted the NEC as law, the older parks are grandfathered in and are not required to update...... unless they are adding onto or rewiring a section of the park then its a whole new ballgame, the inspector can inspect and require the entire park be brought up to the latest code revisions.

The NFPA that produces and prints the NEC have just about priced themselves out, as a new Code Book is $60.  I have a friend who sits on one of the code making panels who give me my copies.

As my two heat pumps are 240 V, I have to be selective about where I stay, or run the genset.

Ed

[belfert]

Nick, your little wiring diagram is priceless, nice job.

Belfert, Yes the National Electric Code does require 50 amp services to be 120/240 V, give or take a few volts.

Article 551.71 states that at least 20 percent of the RV sites have to have  50 AMP 125/250 volt receptacles. (14-50 R)

That said, there are 7 or 8 states that haven't adopted the NEC and you are at the mercy of whoever designed/wired the park.

Right now the NEC people are trying to come up with a higher ampacity receptacle/plug set because more and more big rigs need more power.

How hard can it be to come with a new plug/receptacle for an RV with over 50 amps?  The 50 amp plug for RVs is the same plug used for a 50 amp range plug.  Personally, I would like to see them use a twist lock connection if they come up with something different.  My question is why does anyone need more 50 amps at 240 volt?  50 amps should be enough for four roof tops with enough extra to run a household fridge and some other stuff.  There is a hard enough time finding parks with 50 amp service.  I can't imagine finding parks with more than 50 amp service.  The local state fairgrounds campground has only a few 30 amp sites with mostly 15/20 amp service.  They are only open 21 days a year and fill up so they aren't willing to upgrade.

What are states using for electrical code if not the NEC?  I assumed the NEC was adopted in all states.

[Kristinsgrandpa]

Brian, the NEC can be adopted in its entirety or with exception. New Jersey adopted it with exception, being Article 551, that covers RV's and campgrounds. So in NJ and all the other states that haven't adopted it yet you can wire your coach or your campground with baleing wire if you want to.

That is why last week someone on the other board posted a voltage check at a campground with a reading of 70 volts to ground.

Ed

[Lin]

When I did the electrical on my first bus, I decided that I would not need 240v but did want 50amp to be able to run both AC's.  I used a 240v, 50 amp plug, removed one of the hot prongs, and used a 3 wire, #6 cord.  I felt that I was saving about 25% on the weight of the cord.  I had a jumper between the panel legs, so every space got current.  This bus has a similar system in a way.  The generator is producing real 240 and is wired to an outlet.  The shore power cord is wired to a separate outlet with a 3 wire cord.  There is a jumper in the shore power outlet to light the second hot.  The main panel is plugged into either outlet with a 3 prong, 240v, dryer-type plug.  Therefore when plugged into the generator outlet, the panel gets real 240 (though only 30 amps per leg).  When plugged into the shore power plug, the panel gets up to 50 amps at 120v sent to both legs.  I am not an expert, so I m probably missing whatever pitfalls the system has.

[oldmansax]

One thing that has not been mentioned here is you are also at the mercy of the KNOWLEDGE of whoever wired the park. Everybody may have had the best of intentions, they just did not know what they were doing. I am sure everyone on this board has run across somebody who had the correct credentials & still didn't know what they were doing 

I have a friend who says "Some people don't know anything, and some don't even SUSPECT anything"   

I think the best advice is KNOW what the readings should be for any given electrical service and ALWAYS check BEFORE you plug in.

TOM