Cruisers Forum
Main Forum => General Discussion => Topic started by: billy on July 20, 2011, 10:32:08 pm
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At our place I have 30-amp service. But my inside plug in meter is in the red when running the A/C. One of the problems is the 30 amp has about 25 feet run and from there is where we plug our 25’ cord in. And it’s been a long time so I’m not sure how big of wire I originally used.
Next to the rig, in the wall of the garage I do have a 220-amp welder service. Now do our rigs run on a single 30-amp service, 1 hot line, 1 natural and 1 ground? Or?
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I checked my set up and it looks like 30-amp service, 1 hot line, 1 natural and 1 ground? I'm going to someone who has help me and knows his stuff.
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Billy,
From what you said about your distance on your line, leads me to believe you are experiencing line loss. The minimum I would use for a 30 amp circuit would be 10 guage. Other factors come in to play on choosing the wire size. Such as the distance of the run(and add your coach cable length to this run factor), is it an overhead run or buried in the ground, and also if buried you need to consider the type of burial. Is it direct buried or in a conduit. Just some things to consider. Our units are hot, neutral and third wire ground. I would not rely on the plug in meter, but would use a regular VOM, either analog or digital for an accurate read. As far as your 220 volt welder, if you knew how to, you could tap into the one phase of the 220 for your coach, but not use welder at same time coach is hooked up.
Bob
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Bob, I rewired the 220-amp welder. Purchased a new 30-amp breaker, a 30-amp RV receptacle. Taped off one wire, even though it was not connected, wired the 30-amd Rv receptacle, installed the new breaker and wala. With the A/C running my meter now is in the green. For the welder I had used a #8 and the length is about 15'. So every thing is good.
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Billy,
It was good you used #8 because that should eliminate all line loss. Mission accomplished in the green.
Bob
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2551 Phoenix w/30 amp - I carry a 25 foot 10 gauge extension cord incase I'm at site that needs the extra length to reach the post. Recently an electrician at an RV park told me I should be using a 25 foot 8 gauge extension cord because of heat and line loss. I've been checking around and haven't found any available for 30 amp. It has me wondering if because the RV places don't even carry the 8 gauge maybe what I was told is not right. Does anyone have any expertise as to what is correct or what is the safest wire gauge to be using for an extension cord for 30 amp service?
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NLK, I use a voltages tester EVERY TIME BEFORE I PLUG IN. We have just upgraded our electrical system in our park in Pismo Beach. Remove all the old aluminum wiring, all new copper. Lots of work, lots of money. On my first trip back I was assigned space 82. First thing I plugged in my line tested and found a bad ground. Used my 50-amp adaptor. Our park manager found it was just a bad receptacle.
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2551 Phoenix w/30 amp - I carry a 25 foot 10 gauge extension cord incase I'm at site that needs the extra length to reach the post. Recently an electrician at an RV park told me I should be using a 25 foot 8 gauge extension cord because of heat and line loss. I've been checking around and haven't found any available for 30 amp. It has me wondering if because the RV places don't even carry the 8 gauge maybe what I was told is not right. Does anyone have any expertise as to what is correct or what is the safest wire gauge to be using for an extension cord for 30 amp service?
The site I checked: http://www.solarseller.com/dc_wire_loss_chart___.htm
says 35 feet maximum with 10 gauge at 30 amps. They also have some other interesting voltage drop charts for various voltages.
Here is a site that has a NECA calculator and it agreed saying 8 gauge if aluminum wire. http://www.paigewire.com/pumpWireCalc.htm
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If I was using a 25' extension to the coaches original 25', then I would want a #8 on the extension. That is using copper wire, on 120 volt single phase. If per chance you are using an aluminum extension cable, then you should use #6. I would never use aluminum as there are too many problems with heat and dis-similar metals.
Bob
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If I was using a 25' extension to the coaches original 25', then I would want a #8 on the extension. That is using copper wire, on 120 volt single phase. If per chance you are using an aluminum extension cable, then you should use #6. I would never use aluminum as there are too many problems with heat and dis-similar metals.
Bob
Looks to me like we are way under rated on what we carry for extensions. Having said that, welding supply houses in Tulsa carry both 25 and 50 foot #8 230v extensions for welding machines, appropriate mods will probably have to be made, i.e., crossover adapters, but the amp capacity is around 40 amps.
On second thought, I have carried the Wallyworld extension for several years and never once used it...........................besides those #8's are pricey.
Okay I'm gonna call it: this is a can of un-opened worms.
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Are you saying that using these extension cords is questionable? I assumed they were all rated to the 30amp application.
(http://images.campingworld.com/is/image/cwi/20000/24490a.jpg?wid=1206)
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You will all go crazy figuring out what wire size extension cords you need. It is a function of actual voltage at the plug in source, the desired minimum acceptable voltage at the breaker box on the RV, total amps flowing (assume 30 for 30 amp service), ambient temperature, wire size, and probably other things I'm overlooking. I just browsed through a lot of info on the web and came to the conclusion that if you're buying a 25 foot long 30 amp rv cord, you'll have real fun trying to find anything but 10 gauge wire. For 50 foot cords, 6 gauge is recommended, but hard to find. As you will find out if you price them, heavier wires than 10 gauge get realy pricy. If you have a 25 foot cable on your PC, I think you'd want to think twice about adding more than another 10 to 15 footer without going up over 10 gauge. The easiest way to do that is probably buying a 50 amp cord and a couple of 30 to 50 dogbone connectors. The dogbones don't cause much voltage problems since voltage drop is a linear function of length as well as diameter. Please note I am NOT an electrician, but an electrical engineer by degree many years ago, so I am not nearly as practical a guy as most of you.
Jerry
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So in summary then.......
When extending your PC's 30 amp yellow power cord with one pictured above, it is recommended not to add more than one additional 25 foot, 30 amp extension cord purchased from Walmart, Menards, or other retail outlet. The extra 25 feet might be getting near or slightly exceeding the recommended length when running the A/C, so be observant.
If you need to add 2 or more 30amp extension cords to reach the power peg, do NOT run the A/C that way. If you need A/C, run the generator or engine's dash board A/C. With a 30amp extension cord, limit your 110v usage to regular house hold items.
How does that sound?
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I try to be extra careful because I have minimum knowledge when it comes to electric issues. As always, the folks in this forum have proved to be of great help. Everyone .... Thanks for all the assistance.
tymote
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One pretty sure indicator, IF, you have a line meter is the actual voltage drop when plugged in and running whatever load. My old MH would do a shut down of microwave, tv's, converter and AC units if voltage dropped to 96V. When I notice the meter dropping below 105V I start shutting things down until it comes closer to the norm established when I first plug in. I believe I read somewhere that a brownout is considered to be between 95-105V, so that is where I draw the line. A hundred years or so ago the campgrounds power to the pedestal was "iffy" but I have not seen the big drops (below 105v) that I used to see in the early 80's-90's.
I will bet there are some remote campgrounds with power problems, but most have been updated to keep the 45' monsters coming back.
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Yes, I do have a meter. 105/110 being the lowest point to drop to, then start turning things off ... that's good to know.
Every tidbit of information I can pick up along the way is appreciated and it will help my much needed "RV Electrical Education". Thank you !!!