RV circuits can easily get you into trouble if you are not sure what you are doing, a 50 amp hookup will take 4 wires and 240 volts but a 30 amp hookup is only a 3 wire 120 volt circuit. On all but the biggest of movie star type motorhomes all of the loads are 120 volts, and a normal RV with a 50 amp hookup utilizes the incoming 240 volts as two 120 volt lines. Seen more than one RV get fried by someone running 240 volts into a 30 amp TT hookup. So legally you can only use a 30 amp breaker on your #8s if you are connecting directly to a 30 amp TT receptacle. About the only way you can cover all the bases is with a special RV panel which would contain a 20,30 and 50 amp receptacle with circuit breakers. What type of wire are you using, I assume it will be underground? This post was edited by joefixit2 on Mon, Feb 10, 14 at 20:57

We live on 5 acre place--small farm/garden/greenhouse/water ponds/etc. ... I have a motorhome where I usually have 150 watt solar panel keeping auxiliary batteries at full charge--rv is in shop indefinitely, maybe forever... And, I am curious if there is not a creative idea for what to do with the solar panel in the meanwhile. Thanks in advance for any suggestions or links. My thinking originally is to go direct to a variable load that can handle anything the panel can throw at it, with at most a small cheap controller in the loop. A solar-powered "water-wheel" in garden or a fountain of sorts, to trickle into a small stream and water some herbs on hot sunny days?

Once again, I am no expert, but just moving the breaker with its corresponding wires attached to another position in the panel, in my opinion, won't accomplish much because all the slots in the panel are tied to the same bus bars. What I suggested was to leave all the breakers in place, but let's say the troublesome breaker feeds "2nd storey lights and receptacles" and another AFCI breaker in the panel feeds "hall and living room lights". You would leave the breakers in place, and disconnect the hot wires going to "2nd storey lights" and "hall and living room" from their respective breakers. Then take the wire feeding "2nd storey lights" and connect it to the breaker that before was feeding "hall and living room", and the wire that once fed "hall and living room" would go to the troublesome breaker. If the problem is still with the "second storey lights", which are now hooked up to where "hall and living room" was before, it's safe to assume the problem lies within the wiring of "2nd storey lights and receptacles". If the problem is now with the "hall and living room", then it's safe to assume that the circuit wiring is not at fault and you are getting nuisance tripping, probably from the solar system. The other test I was suggesting about was to leave the breaker attached, and turned on, and leave its neutral pigtail connected to the neutral bus, but remove the hot (usually black or red) from the breaker. This way, if the breaker trip with nothing connected to it, it has to be nuisance tripping. Because you mentioned several lights and outlets in 5 rooms, my suggestion for you not to lose power to a good portion of your house, was to add a regular breaker, less expensive than an AFCI breaker, and buy an AFCI receptacle (they look just like the GFCI receptacle in your kitchen or bathroom, with test/reset buttons, but they trip on arc faults instead of ground fauts) to feed the circuit. This way the whole circuit (except for the short run between the panel and the AFCI receptacle) is protected agains arc fauts, but I would imagine that the receptacle would be less subject to stray voltages or surges that might occur in the panel. As far as the low ohms thing, I would not thing too much about it, we are missing information to really use that to troubleshoot. Here's a brief explanation of ohms. Ohms is the unit of measure of electrical resistance, just like the pound is the unit of measure of weight and the ampere is the unit of measure of electrical current. Good electrical conductors, like copper wiring in a house, have a resistance very close to 0 ohms. Poor conductors, like plastic or rubber, have a very high resistance in the order of several megohms (millions of ohms). Depending how and where they were measuring, "low ohms" could mean different things. If they were measuring ALONG wires, they were checking for a loose connection that could cause arcing and tripping of the breaker. In that case, you want the resistance to be as close to 0 as possible. Measuring ACROSS two wires, which is what it sounds like they were doing if they "found low ohms when testing the red wire to ground up in our attic", on a branch circuit, will only measure the resistance of what is connected to the circuit, like the resistance of every light bulb, ceiling fan motor, perhaps a radio or laptop plugged into a bedroom receptacle. Devices are connected in parallel, therefore the resistance measured across the hot and neutral wires of the circuit will vary according to what is connected or plugged in. For instance, a regular incandescent 100-watt bulb will have a resistance of roughly 150 ohms, but a vacuum cleaner could have a resistance as low as 10 ohms. It is normal, and the only way possible, to measure resistance with the circuit powered off.

Elmer, my cash flow point is correct. But for some, cash flow is a difficult concept. Your comment entangles a lot of financial concepts, so let me try to make order of it. “monthly cash flow savings”: Cash flow is not savings...it is cash flow. It can be positive or negative. If debt costs me $10 a month for an investment that generates $12 a month, then I have a positive cash flow. And that’s not a “so what”. If that investment is cash flow negative, then there must be another stream of cash used to make the investment possible. For some, added cash may not be available. If an investment has a negative cash flow, it hopefully has a larger payback in the future in order to make sense…such as buying a home which entails a negative cash flow but presumably an appreciated asset upon sale. But with an investment that is not expected to appreciate…such as buying a car…then we have to look to the service received from that investment — such as getting us to work where we can make money to pay the car loan — to determine if the payback from that investment is worthwhile. Solar panels don’t appreciate. Studies I’ve seen are a mixed bag as to whether they add to the sales price of a home, so we’re left with the service received off of them, the value of which is subject to the vagaries of electricity costs. But based on specific locational factors such as the local cost of electricity and insolence, it may pay. “Investment return is lost from the reduction in invested funds and that's a real cost that would otherwise offer a compounded return.” This is opportunity cost…what is the return of the foregone investment, and does it exceed the return from the investment under consideration. If the funds are losing money, then switching them to a positive return investment is a good thing. But if the funds are making more money than the proposed investment, that’s not a good thing. But that is not specific to an investment in solar panels. And that’s different from cash flow. “If the utility cost savings isn't enough to pay for the equipment within a reasonable period of time, putting in solar equipment if thought to be done for money reasons would be a poor choice, a net cost and not a savings.” This is bringing in the issue of payback time….how long it takes to recoup your investment. Maybe the payback is too long based on the opportunity costs of other investment choices, or the useful life of the asset, or the costs of the foregone liquidity, but that doesn't make it cash flow negative. Moreover with a positive cash flow, the payback begins immediately, not at some future date.