# shore power



## dastout (Dec 22, 2008)

Just built nice big garage for my 2001 dutchstar and installed a 50 amp outlet so I can plug her up. My question is would it be better to leave power on all the time to the coach or is it better to leave it off except when needed. I would like to leave it on but do not now if some gremlin converter, inverter or pervert would wear out or burn out. The batteries would be kept charged ect,ect. What do ya'll think??
Thanks folks And Merry Christmas


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## Guest (Dec 22, 2008)

RE: shore power

I say Leave it plugged in ,, it won't hurt a thing ,, and with u'r rv u prolly have the smart converter/batt. charger ,,,, but one thing ,, do ck u'r battery water level ,, atleast once a month ,,, and add when needed ,, will save alot of hassles later ,,, also put a trickle type charger on u'r engine battery ,, most DO NOT charge when plugged in ,, and ck that battery also for water monthly ,, other than that ,, enjoy u'r new rv garage  :approve:  :approve:    :bleh:


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## H2H1 (Dec 22, 2008)

Re: shore power

Comgrats on the garage, as 730 stated  it is ok to keep plugged into shore power. I have a 30 amp outlet and keep mine plugged in. But as 730 mention keep an eye on the water level and add if low , but not just any water will do, you must have distilled water to add to the batteries. Good Luck


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## C Nash (Dec 22, 2008)

Re: shore power

Garage sounds great. I leave mine plugged up all the time when home with fridge on. No problem so far and been doing it since 2002 but on the road a lot. Like others I ck the batteries about once a month. Guess the plug it up is ahead so far.


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## miket (Dec 22, 2008)

RE: shore power

Of course the outlet is 220V --  If it isn't 220, the neutral could carry too much current if it's two legs off the same 120V side of the house breaker box.


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## Grandview Trailer Sa (Dec 22, 2008)

Re: shore power

*Maybe I misunderstood, but NOTHING IN AN RV IS 220volts!!!!!!!*


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## H2H1 (Dec 22, 2008)

Re: shore power

BEAT TO THAT KEN


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## Guest (Dec 22, 2008)

Re: shore power

well yes a 50 amp is 220 ,, in a since ,, most have one leg that is 120/30amp carries the coach stuff ,,, the other 120/20amp usally only runs say the a/c if u only have one ,, or maybe even the other stuff that they din't want on the main 30amp circuit ,,, most rv manfacts do it that way ,, splitting the load ,,, all are different ,,, but this is JMO ,,,, and u don't want to know how i wire 30amp rv's to run both a'c units on a 50amp plug    :laugh:  :laugh:  :laugh: 
I am in no way doupting  that a 50amp is a 220 ,, just 2 different breakers ,, usally on 30 amp and one 20amp ,,, not like the single double breaker that is 30amp apiece = 60amps  
I am not trying to start anything ,, and i know there will be others that have their opinion ,, i have no prob with that ,, I'MO ,, and others have theres  :approve:  :approve:  :approve:


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## SnowbirdInFlight (Dec 23, 2008)

Re: shore power

Okay, I know I'm just a woman, but even I know that 50 amps is NOT the same as 220 volts. This is a HUGE mistake a lot of RVers make when setting up their electric at their homes. Our dealer said a lot of RVs have been fried because the buyer confused 50 amp service with 220 volt service at their homes. I totally agree with GTS.


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## miket (Dec 24, 2008)

RE: shore power

First, I never said that there was 220V appliances, but the feed is 220V. 

Second The big mistake is when some one wires a 30 Amp as 220V.

Third ..   A 50 amp coach is supplied by 220V, but the way most coaches are wired, they use the legs as separate 120V legs. The reason is that the two hot leads and the neutral are the same wire guage, and the ground wire is usually a little smaller, since it is not used to carry power. The reason it is 220V is because 220V is 180 degrees out of phase, and the neutral currents cancel so the conductor will only carry 50 amps max, not 100. Both hot legs are 50 amps. You get 3600 Watts power from 30 Amp service, while 50 Amp is 12,000 watts.

If you wire a RV 50 amp outlet without 220 across the two hot legs, the current in the neutral will exceed 50 amps and cause over heating of the conductor.

 Here is a link that explains it. You need to scroll beyond the 12V stuff -----

http://www.dasplace.net/RVWiring/wiring.html


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## TexasClodhopper (Dec 24, 2008)

RE: shore power



OK, Mike. So that's what you were talking about! Good info and a great link to it!   

But if there is 'current cancellation' in the neutral, where does that canceled current go?





> miket - 12/22/2008  7:46 PM  Of course the outlet is 220V --  If it isn't 220, the neutral could carry too much current if it's two legs off the same 120V side of the house breaker box.


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## miket (Dec 24, 2008)

RE: shore power

The currents are 180 degrees out of phase, as the illustration in the link, if both legs have 30 Amp current, the neutral has 0 current, it is canceled out. 

At campgrounds properly wired by qualified electricians, the pedestal has a ganged 50 Amp breaker and 240 V across both hot leads.

Problems can arise when cheater boxes are used that plug into the 30 Amp and 20 Amp outlets at a pedestal for a 50 Amp rig. The feeds may not be 180 degrees out of phase, but off of the same 120 feed in the panel. 

This 240V is the same as in a house panel. If anyone is familiar with a house panel, there are two feed bars, one neutral and one ground. Ground is for safety and does not carry current unless there is a problem in a device.

The problem arises when a home electrician wires the 30 Amp RV outlet to 240 because he thinks its a dryer type outlet. This subject has been covered in great detail repetitively at RVNET, and iRV2.

Google the subject and a lot of info is available.


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## TexasClodhopper (Dec 24, 2008)

Re: shore power

Mike, that's all good information and we all appreciate it, but it doesn't really answer my question.

Now, if you have two cars driving at each other on a one-lane bridge (they are 180 degrees out-of-phase), and they crash head on, there's a BIG cancellation and a loud boom and a lot of energy dissipated.

Or, if two people pull against each other with a short rope, each one will eventually get hot and sweaty and wear out and need a beer or a sandwich. The 'cancellation' is visible and sometimes stinks.

But if currents in a wire are 180 degrees out-of-phase, it is simply said that they "cancel" each other out. Where does that canceled current go? There's no loud bang or anything. Does it reduce the current in the 'hot' leg? Does something get hot when both legs are carrying maximum load?  :question:


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## miket (Dec 24, 2008)

Re: shore power

Ask that to an electrician --- all I know is it cancels and the total current is in the hot legs. Because the wire is properly sized, there is no overheating. Usually 3 conductors of 6 guage and the ground  is 8 guage.

In your car example, isn't going in opposite direction 180 out of phase? Never crash, no bing bang boom----


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## ironart (Dec 24, 2008)

Re: shore power

OK.....Here is another thought...

Remember that the power in a 220V circuit is AC (alternating current) which means that it goes from + to 0 and back to + but 180deg. in reverse.
Each phase leg is the reverse of the other which means that when one is pushing the other is pulling and visa versa..
If the power requirement was equal on each leg then there would be no need for the neutral (white) wire.   However, things being as they are, the power requirements are different from one phase leg to the other and the difference will go the neutral (white) to complete the circuit.  Only the differential current will flow in the neutral wire.   If the circuits feeding the 50Amp plug is not a real 220V circuit but just 2 110V circuits in parallel then there will be no current flow from leg 1 to leg 2 because there is NOT a phase reversal.  All of the current used from each leg will have to travel in the neutral (white) wire to complete the circuit......This means that the neutral (white) wire will need to be double the size of the hot legs, because it is receiving current from both the hot wires as it tries to provide a path to complete the circuit.    This extra flow of electricity will overheat the smaller wire and present a problem.


Merry Christmas

Paul


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## C Nash (Dec 24, 2008)

Re: shore power

Now I'm scared to even plug mine in   :laugh:


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## miket (Dec 24, 2008)

RE: shore power



All this just to make sure dastout wired his 50 Amp outlet correctly. If it were wired wrong but the total combined current drawn never exceeds 50 Amps, he's OK, but if it ever went over, the neutral would be overloaded. Plus by code wire size should be 6 guage minimum. If the wire run is of a significant distance, the wire guage needs to be calculated to prevent voltage drop.




*Merry Christmas !!!*


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## dastout (Dec 26, 2008)

RE: shore power

Gee , looks like i stired the pot pretty good with my question about leaving my unit plugged in. Yes I think it is wired correctly, 2 hot legs a neutral and a ground. Wire size is #6 gauge. Coach has been plugged in about a week and all seems fine.

Happy Holidays to everyone! :approve:


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## miket (Dec 26, 2008)

Re: shore power

I'm plugged in 24/7/365  with battery minder on chassis battery.


Hopefully this got the proper info out about true 50 Amp service, that it is 240V, while 30 Amp is 120 at the pedestal.


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## Neal (Jan 6, 2009)

Re: shore power



> TexasClodhopper - 12/24/2008  9:43 AM
> 
> Mike, that's all good information and we all appreciate it, but it doesn't really answer my question.
> 
> But if currents in a wire are 180 degrees out-of-phase, it is simply said that they "cancel" each other out. Where does that canceled current go? There's no loud bang or anything. Does it reduce the current in the 'hot' leg? Does something get hot when both legs are carrying maximum load?  :question:



Let me try to explain in a different light.

If you take two 100 watt light bulbs & wire them in series, then connect them to 220 volts without a neutral, each of the two bulbs will only get 110 volts & will work till one bulb burns out, which will cut the current supply to the second bulb. Remember the Christmas lights that the whole string goes out when one bulb burns out?

The voltage is dropped to each bulb because is has to receive one leg of it's current through a resistor ( the other bulb).

Now if you change one of those bulbs to a 60 watt & leave the other one at 100 watt, then the 60 watt bulb will get high voltage & the 100 watt bulb will get low voltage. (They are now drawing through different size resistors.)

OK, now let us connect a neutral wire at the connection where the two bulbs are connected in series.
In the case of the two 100 watt bulbs, the neutral wire will carry no current and both bulbs will have 110 volts.
In the case of the 60 and 100 watt bulb, the neutral wire will carry 40 watts and both bulbs will now have 110 volts each.
The neutral wire only carries the unbalanced load of the two hot wires from the 220 volt leads.

This is the way almost all residences are wired at the main panel. 220 volt service with the neutral only carrying the unbalanced load from the total house. If you could keep the load balanced at all time, you probably would not even need a neutral but some joker would always want to flip on another light, which would throw the load out of balance.


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## Pancanbob (Jan 6, 2009)

Re: shore power

Hi Neal
That is a real good explanation  , and makes it clearer to me anyway :approve:  :approve: 
Thanks


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## Triple E (Feb 22, 2009)

RE: shore power

Clodhopper, I know that I am late on this question but I will try anyway.  Using Ohms Law the two phases (+,-) will subtract.  So one phase will subtract from the other phase which will equal 0.  The current is not canceled only the phase.  No current no work.  Also, I think that cancel is the wrong word.  I would use balanced.


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## TexasClodhopper (Feb 22, 2009)

Re: shore power

Steve, thanks. I was kind of putting tongue in cheek, but you have the right answer except that something as simple as Ohm's Law does not explain the complex polar/algebraic phase relationships.  :clown:


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## Guest (Feb 22, 2009)

Re: shore power

WOW    Tex that is a big word ,, but to make it simple for others out there ,, he was talking about a bunch of polar bears ,, sitting in a classroom doing algebra ,,,, kinda like the dog picture ,, u know where the dogs are playing pool ,, oops sorry billards (got be politicaly correct now days )  :laugh:  :laugh:  :laugh:  :clown:  :clown:  :8ball:


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## H2H1 (Feb 22, 2009)

Re: shore power

OH BOY ROD, what are u saying about Tex ? :evil:  :clown:


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## TexasClodhopper (Feb 22, 2009)

Re: shore power



Let's confuse Rod just a little bit more ...


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## Guest (Feb 22, 2009)

Re: shore power

u got me tex ,, i used could do that stuff ,, but then agian i was made to ,, in high school ,,,,, btw that don't look like no polar bears in algebra class to me   :laugh:  :laugh:  :laugh:  :laugh:  :clown:


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## Darlin (Feb 22, 2009)

Re: shore power

Looks more like ART work to me :laugh:  :laugh: 

Darlin


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## Guest (Feb 22, 2009)

Re: shore power

actually ,, darlin i think Tex made it up ,, u know that rehab will do that too u ,,, tex is still suffuring from the oil prices taking a plunge ,, and if u don't tell anyone Darlin ,,, that was the secret formula for the oil prices ,,, well it was ,,, back when it was 150 a barrel    :laugh:  :laugh:  :laugh:  :clown:  :clown:  :evil:  :evil: 

Tex u know i jk with u ,,,  :approve:


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## TexasClodhopper (Feb 23, 2009)

Re: shore power

No, you made me mad and I'm never going to come back here again!  :angry:


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## TexasClodhopper (Feb 23, 2009)

Re: shore power

Ok, I'm back. I got lost and hungry.  :clown:


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## Guest (Feb 23, 2009)

Re: shore power

U goof ,, we know how much u love our food here ,,, but don't log on real hungry ,, other wise ,, scooter might show u apicture of a huge hamburger ,, and u might chip a tooth on the monitor  :laugh:  :laugh:  :laugh: 
Btw ,, if anyone is near FL ,, how about giving me and scooter a lift back home ,,, Nash ditched us ,, he left us a note ,, and did say goodbye ,, and pointed the way to the hiway  :laugh:  :laugh:  :approve:  :approve:  :evil:  :evil:  :clown:  :clown:


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## Darlin (Feb 23, 2009)

Re: shore power

Well al least I know that is not one of those shrink therapist ink blots. :laugh: 

Darlin


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## *scooter* (Feb 24, 2009)

Re: shore power

Come on Rod, lets start walking.  I know one of us needs the exercise :evil:  :laugh:  :laugh:    Is that a Burger stand down the road??


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## LEN (Feb 24, 2009)

Re: shore power

AHHHH Tell us xactly how you know it's not an ink blot??????????????

LEN


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## Darlin (Feb 24, 2009)

Re: shore power

Rod told us that it is the secret formula from TC.   :laugh: 

I just remember from watching old movies the the doctor would have things like that.    Hmmmmm.  
Maybe that is where TC got his formula from :question:  :question: 

Darlin


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## TexasClodhopper (Feb 24, 2009)

Re: shore power

I'm trying to tell ya'll how to do it without really telling ya'll how to do it. ..........  :clown:


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## Guest (Feb 24, 2009)

Re: shore power

now tex i used to know my ABC's ,, and numbers ,, hell i can count to ten ,, without using my hands  :laugh:  :laugh: 
scooter ,, that was a optical illusion ,, it was really a prota potty on wheels  :laugh:  :laugh:  :laugh:  :clown:  :evil:


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## H2H1 (Feb 24, 2009)

Re: shore power

OK now TEX


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## H2H1 (Feb 24, 2009)

Re: shore power

OK,Tex is actually trying out for that TV show Numbers and that was just an example of how smart he is :laugh:  :laugh:  :laugh:  :laugh:


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## Darlin (Feb 24, 2009)

Re: shore power

Like   Are you Smarter Than a 5th Grader :question:  :laugh:  :laugh: 

Darlin


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## H2H1 (Feb 24, 2009)

Re: shore power

that's right Darlin, he may be smarter than a 5th grader


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## Guest (Feb 24, 2009)

Re: shore power

all i got to say is OH NO  :laugh:  :laugh:  :laugh:  :laugh:


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## cwishert (Feb 25, 2009)

Re: shore power

Oh I am so confused!     All the man asked was "Is it ok to leave his rv plugged in?"  And there are many good answers and then it gets all technical and then I begin to feel like I'm in the Twilite Zone :laugh:  :clown:


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## Guest (Feb 25, 2009)

Re: shore power

That's just us Carol ,, we do that alot here ,, might be age ,,, might be a soon to be mental state who knows ,,, but i can say ,, it get's worse in the winter ,, u know when we aint out and about in the rv's ,,  :laugh:  :laugh: 
Ok sorry to the OPer ,, we will try and get back on track ,,,, ok guy's and gals ,, we need to be a little more helpfull to the OPer ,,, thanks ,, (like i said ,, mental state )  :laugh:  :laugh:  :laugh:  :clown:  :clown:


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## cwishert (Feb 26, 2009)

Re: shore power

Yeah I know Rod.  I am in a mental state myself.  Can't wait for some temperatures above 80 that last more than a day.  Also can't wait to get back out in the MH.  Especially on the "BEACH"!
   :clown: 
Any way to answer the OP question, we olny plug ours in a few days before we get ready to go unless someone may be using it to sleep in or something in the back yard.  Sometimes the kids like to camp out in the driveway.  Other than that hubby plugs it in on Thursday if we are going on Saturday morning.  I don't think it would hurt anything to leave it plugged in maybe make your electric bill a little higher.


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## Guest (Feb 26, 2009)

Re: shore power

well carol ,, i leave mine plugged in all the time ,, but i do a cycle kinda thing ,,, i turn the breaker on and let it stay on for a month ,, then turn power off ,, and let it sit for a few weeks ,,, and btw ,, i leave my batt disconnect on ,, that way ,, the batts get kinda drained ,,, don't know if it works ,, but since i don't dry camp ,,, i will never know ,,,


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