Go Back   iRV2 Forums > MOTORHOME FORUMS > Class A Motorhome Discussions
Click Here to Login
Join iRV2 Today

Mission Statement: Supporting thoughtful exchange of knowledge, values and experience among RV enthusiasts.
Reply
  This discussion is proudly sponsored by:
Please support our sponsors and let them know you heard about their products on iRV2
 
Thread Tools Search this Thread Display Modes
 
Old 08-16-2012, 04:00 PM   #15
Senior Member
 
BFlinn181's Avatar
 
Gulf Streamers Club
Join Date: Jan 2012
Location: Cincinnati
Posts: 16,229
Quote:
Originally Posted by Hamshog View Post
...If you had 2 cords out of outlets that were on the separate circuits with 15 amp breakers, you would have 240volts @ 15 amps, not 7.5 amps.

Regards, Howard
I wasn't talking about separate circuits, I was talking about both sockets on one outlet.

Sorry I even brought the idea up, it just confuses those reading this thread. The person that wired their TT to a dryer outlet is a case in point. Not only did they hook up wires incorrectly, it sounds like they did it with appliances on.
__________________

__________________

Bob & Donna
'98 Gulf Stream Sun Voyager DP being pushed by a '00 Beetle TDI
BFlinn181 is online now   Reply With Quote
Join the #1 RV Forum Today - It's Totally Free!

iRV2.com RV Community - Are you about to start a new improvement on your RV or need some help with some maintenance? Do you need advice on what products to buy? Or maybe you can give others some advice? No matter where you fit in you'll find that iRV2 is a great community to join. Best of all it's totally FREE!

You are currently viewing our boards as a guest so you have limited access to our community. Please take the time to register and you will gain a lot of great new features including; the ability to participate in discussions, network with other RV owners, see fewer ads, upload photographs, create an RV blog, send private messages and so much, much more!

Old 08-16-2012, 05:04 PM   #16
Senior Member
 
tncruiser's Avatar
 
Ford Super Duty Owner
Join Date: May 2009
Location: kingston tn.
Posts: 973
Exclamation

Quote:
Originally Posted by vegas39 View Post
I understand that your coach is not 220 but your 50 amp feed is. 2x110v legs equals 220, although you dont have anything in your coach that runs on 220, it is running into your coach.
no 2x110 = 110 twice
brianj
__________________

__________________
just liven life in east tn or where ever our
2011 georgetown ,2012 explorer and 02 tbird take us
tncruiser is offline   Reply With Quote
Old 08-16-2012, 05:26 PM   #17
Senior Member
 
MartinC's Avatar
 
Join Date: Jun 2012
Location: Champaign Co. IL
Posts: 343
Let me try to clarify. At the 50A pedestal, in addition to the neutral and ground lines, you have two 120v hot wires. Each of these has a potential of 120v with respect to neutral. In addition, the hot wires are out of phase with each other by 180 degrees. That is to say when one wire is +120v, the other is -120v as they alternate at 60 Hz. Therefore the potential between the two hot wires is 240v. That is how 240v is supplied to a range etc. the neutral wire is only used to tap off one120v leg for control systems and lights.

In a 120v coach, each of those hot wires is led in with the neutral to power different circuits.

I'm an ex-pat Brit and in the UK we have just one hot wire - a single phase 240v. This provides great advantages over the standard US 120v in the area of small appliances where, for the same amperage, one can have twice the power. So, in wiring up our house kitchen, I installed two UK 13amp outlets using the two out of phase hot wires and ground so we can use a very fast 3Kw kettle and other 240v appliances imported from the UK.

Hope I haven't spread any confusion.
__________________
Champaign County Illinois
2016 Thor Tuscany 45 AT, 2014 Jeep Cherokee
MartinC is offline   Reply With Quote
Old 08-16-2012, 05:29 PM   #18
Senior Member
 
calhyatt's Avatar


 
Newmar Owners Club
Freightliner Owners Club
Join Date: Mar 2012
Location: Weston, Fl.
Posts: 914
Well said CHCam42. The coaches are 110V period.
__________________
2003 Newmar Kountry Star 3905, Freightliner XC chassis with CAT 330. Winnie the black lab, pretty Airbus captain wife, retired airline pilot with 11 grandkids. UH-1 pilot (Huey) U.S. Army 1967-1983. RVN 68-69. Northern Idaho my summer home.
calhyatt is offline   Reply With Quote
Old 08-16-2012, 05:45 PM   #19
Senior Member
 
Road Pilot's Avatar
 
Join Date: Aug 2006
Location: Seacoast of NH
Posts: 267
Quote:
Originally Posted by Jimooo View Post
When I wire a 50 amp plug it has 2-120volt hot legs, 1 ground and a neutral wire 4 wires, simply said it is a 50 amp single phase plug., not 220 volts.


Happy RVing, James
That just isn't correct. You were right until you said "not 220 volts."
__________________
06 Millennium Prevost
15 HD Limited Low and 16 HD Triglide (DW)
13 Avalanche Black Diamond with Cruiser Caddie
Road Pilot is offline   Reply With Quote
Old 08-16-2012, 05:49 PM   #20
Member
 
Join Date: Jul 2012
Posts: 86
Quote:
Originally Posted by Jimooo View Post
When I wire a 50 amp plug it has 2-120volt hot legs, 1 ground and a neutral wire 4 wires, simply said it is a 50 amp single phase plug., not 220 volts.


Happy RVing, James
I cant believe this thread caused so much confusion. Ok, so our coaches run on 110 volts.
A 30 amp service is a hot, a neutral and a ground, 110 volts out from supply and 110 volts into the coach.
A 50 amp service is 2-hots, a neutral and a ground, 220 volts out from the supply and 220 into the coach. So nothing in the coach runs on 220 but it is still considered a 220 volt line!
The next time some of you non believers are at a park pedestal, take a meter and read across the two hots of a 50 amp outlet, bet it says 220 give or take a few volts.
Any electrician will tell you, even though they are seperate 110 volt lines, it is still considered a 220 volt service.

People also seem to be confusing single phase as 110 volts and double phase as 220, doesnt work like that. Whether it be 110 volts, or 220, it is still single phase on our coaches.
Our 30 amp service comes from a single pole breaker and our 50 amp service comes from a double pole breaker.

Now that I got that off my chest, can someone please tell me what they think of the idea in my beginning post?
__________________
vegas39 is offline   Reply With Quote
Old 08-16-2012, 05:52 PM   #21
Member
 
Join Date: Jul 2012
Posts: 86
Quote:
Originally Posted by CHCam42 View Post
My brother in law thought the same so he wired his 50 amp travel trailer to 240 like a clothes dryer. Unfortunately he had two AC on and the stereo when the smoke cleared he had to replace the two AC's, stereo and tv. Expensive lesson.
As said before, he wired it wrong.
__________________
vegas39 is offline   Reply With Quote
Old 08-16-2012, 11:00 PM   #22
Member
 
Join Date: Jul 2012
Posts: 41
vegas39,

There's a lot of confusion on this thread because electrical power is so widely misinterpreted and poorly communicated. I'm a power generation high voltage electrician, and I can tell you even among us tradesmen there are common misunderstandings. Electricity has some kooky terminology that easily gets conflated.

I could get long-winded about everything gone awry in this thread, but that wouldn't serve any purpose. But please, everyone... consult with a professional before playing with dangerous energy. And, as stated by a few, this is a 50A 240V single-phase center-tapped (split phase) service with two 120V legs. 120V in reference to ground or the grounded (neutral) conductor. The same stuff you see in a residential home.

Quote:
Originally Posted by vegas39 View Post
Hi all. So with my 30 amp setup, I've read several methods of tapping in back by the gen for a second plug for the extra a/c unit, easy enough but why couldnt a person mount a small sub panel with a 30 amp breaker for the coach and a 20 amp breaker for the second a/c and then maybe an ATS to avoid having to plug the a/c in and out of the generator? This way I could have a 50 amp cord on the coach.
I understand that 50 amp service is 220 and the sub panel idea works great because it has two seperate poles, one for my single pole 30 and the other for the single pole 20.
Now, what about parks that only have 30 amp plug ins? What does the 50 amp crowd use in that situation? Is there an adapter that splits the voltage between both legs of the plug, or does it eliminate one leg?
Thanks for the insight, I wanted to get some pros and cons from some people before tackling this idea. Thanks!
Disclosure: I don't own my rig yet... haven't had any hands on with these systems. Also, I'm not familiar with the common setups or "tricks" in order to squeeze a little more functionality out of them. That said, maybe I can help a little.

If I understand you correctly, you want to be able to run your second air conditioner (if needed) with your genset while connected to 30A shore power, but be able to power it by shore power alone if a 50A service is available. Ya?

Sure, I suppose you could just add a switch plus a 20A breaker in a box for the a/c alone and rig up another leg for a "50A" connection. Just make sure your conductors and breakers are properly sized and has been double-checked by an electrician. Even better, you could upgrade (replace) the panel to accept a 4-wire connection. That leaves room for expansion if you decide to add circuits later.

Why an ATS? Seems like overkill when a manual switch would work just fine.

Not sure about the 50-30 adapters, but it wouldn't make sense to eliminate a leg. If they did that every branch circuit on that leg would be dead. Makes sense to parallel (share... split... divide) the leg. Remember though, you still only get 3.6kW from that; 30% of a 50A pedestal.

Not sure if that answers anything for you or not, but hopefully it helps a little.

- K
__________________
Kwayzhar is offline   Reply With Quote
Old 08-16-2012, 11:18 PM   #23
Member
 
Join Date: Jul 2012
Posts: 86
Quote:
Originally Posted by Kwayzhar View Post
vegas39,

There's a lot of confusion on this thread because electrical power is so widely misinterpreted and poorly communicated. I'm a power generation high voltage electrician, and I can tell you even among us tradesman there are common misunderstandings. Electricity has some kooky terminology that easily gets conflated.

I could get long-winded about everything gone awry in this thread, but that wouldn't serve any purpose. But please, everyone... consult with a professional before playing with dangerous energy. And, as stated by a few, this is a 50A 240V single-phase center-tapped (split phase) service with two 120V legs. 120V in reference to ground or the grounded (neutral) conductor. The same stuff you see in a residential home.



Disclosure: I don't own my rig yet... haven't had any hands on with these systems. Also, I'm not familiar with the common setups or "tricks" in order to squeeze a little more functionality out of them. That said, maybe I can help a little.

If I understand you correctly, you want to be able to run your second air conditioner (if needed) with your genset while connected to 30A shore power, but be able to power it by shore power alone if a 50A service is available. Ya?

Sure, I suppose you could just add a switch plus a 20A breaker in a box for the a/c alone and rig up another leg for a "50A" connection. Just make sure your conductors and breakers are properly sized and has been double-checked by an electrician. Even better, you could upgrade (replace) the panel to accept a 4-wire connection. That leaves room for expansion if you decide to add circuits later.

Why an ATS? Seems like overkill when a manual switch would work just fine.

Not sure about the 50-30 adapters, but it wouldn't make sense to eliminate a leg. If they did that every branch circuit on that leg would be dead. Makes sense to parallel (share... split... divide) the leg. Remember though, you still only get 3.6kW from that; 30% of a 50A pedestal.

Not sure if that answers anything for you or not, but hopefully it helps a little.

- K
I couldnt believe how confusing this thread got! Yeah, the 50-30 adapter splits the two legs of a 50 amp service and in that case, you would be back to step 1 with not being able to run that extra a/c.
From what I've read, some people plug the 30 amp cord in and use a seperate cord plugged into the 20 amp outlet on the pedestal, I just wanted to make a little more permanent setup.
Living in hot Las Vegas, we really need two a/c units running when we have this thing parked at our house. I have all the wire and everything else I need to add a 50 amp outlet to the front of our house, so I'll probably go ahead and do the 50 amp setup for the coach.
__________________
vegas39 is offline   Reply With Quote
Old 08-17-2012, 09:10 AM   #24
doc
Senior Member
 
doc's Avatar
 
Appalachian Campers
Join Date: Sep 2002
Location: Dixie !! (north Georgia) USA
Posts: 2,953
Dear Lord! It is quite a wonder that there are not more RV fires!!
__________________
doc is offline   Reply With Quote
Old 08-17-2012, 10:09 AM   #25
Member
 
Join Date: Jul 2012
Posts: 86
Its like our house we had in California. We had nothing that ran on 220 but the service to the house was still 220, 2-110 lines and a neutral, just like a 50 amp rv.
I find it funny that so many are so confused about this. If I had known what it would turn into, I wouldnt have started this thread.
__________________
vegas39 is offline   Reply With Quote
Old 08-17-2012, 11:01 AM   #26
Community Administrator
 
Route 66's Avatar


 
Newmar Owners Club
Retired Fire Service RVer's
Spartan Chassis
Join Date: May 2000
Location: Newark, DE
Posts: 25,608
You got it!

Don't worry about the confusion. It happens just about every time this comes up.

Quote:
Originally Posted by vegas39 View Post
Its like our house we had in California. We had nothing that ran on 220 but the service to the house was still 220, 2-110 lines and a neutral, just like a 50 amp rv.
I find it funny that so many are so confused about this. If I had known what it would turn into, I wouldnt have started this thread.
__________________
Adios, Dirk - '84 Real Lite Truck Camper, '86 Wilderness Cimarron TT, previously 4 years as a fulltimer in a '07 DSDP

Route 66 is offline   Reply With Quote
Old 08-17-2012, 12:12 PM   #27
Registered User


 
Monaco Owners Club
Join Date: May 2009
Posts: 3,198
one thing that is really worth mentioning is that most 50 amp RV's, and many 30 amp RV's, have a fairly smart and somewhat expensive energy management system, you really do not want to do anything that might blow it up...

As was stated, an RV 50 amp connections provides 110/220 50 amp power, on 4 wires, 2 out of phase 110v hots, a neutral, and a ground.
(we could wire a 240volt dryer in our motorhomes, I've often wondered why splendide didn't, it would work a ton better!)

The difference between a dryer/range/welder outlet and an RV outlet is the neutral. Home 220v outlets are 3 wire, no neutral, you cannot get 110 volts off that plug (never ever draw current thru the ground wire!!!)

All 3 of the 50 to 30 adapters I have owned connect to only one leg of the fifty amp plug. In fact, that is how the EMS in my rig knows it is connected to 30 amp power... one hot leg, one dead leg.

Somehow, regardless of what I plug it into....

It "KNOWS"! and it is able to power all of it's circuits regardless... as long as I don't exceed whatever amperage the EMS thinks it is connected to.

Unless you have an old old rig that doesn't have an intelligent energy management system, I'd caution you not to mess with this. Let the system do it's thing.
My system WILL run both A/C's on 30 amp power, as long as nothing else is drawing power. That nothing else is often the converter/inverter. That 100 amp charger can pull a BUNCH of power.

If you have a system like mine, just wait for the charger to go to "FLOAT" or "absorb" before you turn on that rear AC.
__________________
JimM68 is offline   Reply With Quote
Old 08-17-2012, 02:41 PM   #28
Member
 
Join Date: Jul 2012
Posts: 41
Quote:
Originally Posted by JimM68
Unless you have an old old rig that doesn't have an intelligent energy management system, I'd caution you not to mess with this.
Very good point.

But (there's always a but) ...The manufacturer's literature may give parameters when modifying... for the courageous or gambling type.
__________________

__________________
Kwayzhar is offline   Reply With Quote
Reply



Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


» Virginia Campgrounds

Reviews provided by


Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -6. The time now is 10:11 PM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.