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James R.
Runaway Bay Texas
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I have a 2006 5th wheel with dual A/C, elect.W/H, no washer or dryer ,wired for 50 amp service. I borrewed a device that has 30 pigtail and 20 amp pigtail going into 50 amp female plug ,also 20 amp is not GFI, when I started second A/C the 20 amp breaker threw,while other A/C continued to operate on 30 amp side,my question is can the two breakers be tied together ? Or balanced ? Help ! This is 50 amps but can't exceed amps on smallest breaker ,I can't choose whitch side to get elect from.
James
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YoDude9999
San Martin, CA
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An adapter that allows you to plug a 50 amp shore cord into it, doesn't mean you can get a full 50 amp service from it.
50 amp service, by the way, is really two 120 volt 50 amp legs. Generally these adapters connects one of the 50 amp legs to the 30 amp service and the other 120 volt 50 amp leg is connected to the 20 amp service. In total, yes you get 50 amps worth of service, BUT, you must consider them as completely separate circuits. So, what you really have is one 30 amp service and one 20 amp service.
You must restrict the amount of current you draw from the 20 amp side. Without knowing how your rig is wired, the only way you'll be able to figure things out is by leaving the 20 amp side unplugged and see what doesn't work. Then you'll be able to find out what you can actually run on that side of the circuit.
See my 'links' page and scroll down to 'Electrical stuff you NEED to know' for far more detail about this.
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RVUSA
Orlando, FL, USA
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This is assuming you meant the 20 amp breaker in the house was popping.
Sounds like you have too much voltage drop in your feed. A/C compressors pull a lot of current when first starting up. Problem with that is the compressor will try and pull even more current than normal under low voltage (voltage drop in the shore cord and adapter) and thus will pop your 20 amp breaker.
I made a 50 to 32/20 pigtail, and use it with my rig all the time. So you can do it, you just have to determine whats wrong with your setup.
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sailormike
Wrightsville Beach, NC
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sometimes on rigs with 2 ac units and 50 amp power one ac is on one leg and the other on the other leg
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RAM^3
Wharton, Texas, USA
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James R. wrote:I have a 2006 5th wheel with dual A/C, elect.W/H, no washer or dryer ,wired for 50 amp service. I borrewed a device that has 30 pigtail and 20 amp pigtail going into 50 amp female plug ,also 20 amp is not GFI, when I started second A/C the 20 amp breaker threw,while other A/C continued to operate on 30 amp side,my question is can the two breakers be tied together ? Or balanced ? Help ! This is 50 amps but can't exceed amps on smallest breaker ,I can't choose whitch side to get elect from.
James A few points:
1. That 2-cord-and-a-socket will be drawing all of its power from the same feed line: you'd be as well off to use a simple "dogbone" adapter that plugs into the 30A socket. By "feed line" I'm referring to the wires that actually deliver electricity to the pole. If no 50A socket is present then the pole is most likely wired to supply no more than 30A 120v to all the plugs combined.
The "dogbone" supplies current to both "legs" of the 50A service. [The dealers will, often, include one with the trailer.]
2. You may well wish to "balance" the electrical load in your trailer's circuit breaker box: all too frequently, the manufacturers will put almost all of the circuits on one side. By balancing the load, you may be better able to run "things". [I found this to be necessary for efficient use of my generator to avoid tripping its double-pole circuit breaker when one "leg" exceed 30A demand. By moving a few circuits from one "leg" to the other, the demands were better balanced, thus enabling us to run everything at once while on generator power.]
3. Don't expect to be able to run both air conditioners at the same time.
4. The "leg" being fed by the 20A cord was presenting too high a load for the pole's breaker. See point #2 (balancing) above.
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wittmeba
Virginia
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YoDude9999 wrote:An adapter that allows you to plug a 50 amp shore cord into it, doesn't mean you can get a full 50 amp service from it.
50 amp service, by the way, is really two 120 volt 50 amp legs. Generally these adapters connects one of the 50 amp legs to the 30 amp service and the other 120 volt 50 amp leg is connected to the 20 amp service. In total, yes you get 50 amps worth of service, BUT, you must consider them as completely separate circuits. So, what you really have is one 30 amp service and one 20 amp service.
This is the best explanation I think I have ever read regarding 50 amp rigs connected to 20/30 amp pedestals. Very well said.
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Rick Jay
Greater Springfield area, MA
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wittmeba,
I agree, YoDude9999 did a good job of explaining the connection. If you couple it with point #1 in RAM^3 post, then we can see why 30A + 20A might only equal 30A! (New math, ![[emoticon]](http://www.rv.net/sharedcontent/cfb/images/smile.gif "smile") ) In such a case, the dogbone is probably a better option because you're not "fooling yourself" into thinking you have 50 amps to play with.
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wittmeba
Virginia
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Rick Jay wrote:wittmeba,
If you couple it with point #1 in RAM^3 post, then we can see why 30A + 20A might only equal 30A! (New math, )
~Rick
Fully agree...thats why I have said the term '100 amps' should NEVER be used. You still only have 2 - 50 amp circuits. (50 + 50 = 50 ).
* This post was
edited 05/21/06 12:45pm by wittmeba *
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YoDude9999
San Martin, CA
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Within the next couple days, I hope to explore this all a bit more on my site and have something there that will explain some different possibilities with it all. I've started on a drawing that may help to explain it more closely. I'll re-post on this thread when I've completed the page.
Yo-
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Rick Jay
Greater Springfield area, MA
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wittmeba wrote:Fully agree...thats why I have said the term '100 amps' should NEVER be used. You still only have 2 - 50 amp circuits. (50 + 50 = 50 ).
Well...THAT I believe, IS incorrect. It's up to 50 amps on each line. Independently. The dual breaker protects each line at 50 Amps. 50 + 50 does in fact equal 100.
If the circuit is used on a true 240V application, the circuit is protected at 240V * 50A = 12,000 Watts. If the circuits are split for a 120V/240V application, as is done for RV's, then EACH circuit is protected by a 50A breaker at 120V * 50A = 6,000 Watts. Since there are two of these circuits, it is possible to draw up to 12,000 Watts IF 50A is drawn from each line. Although that would be pretty rare to equally balance both lines, it's quite possible to draw up to 50 Amps from one line, and independently draw up to 50 Amps from the other line. In such a case, one line by itself can handle at least as much current as BOTH 30A & 20A circuits could provide under the best of conditions.
Bottom line is this is at least double what could be provided by the 30A & 20A pigtail device mentioned in the original post.
~Rick
* This post was
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