thgoodman wrote:
My A/C electrical system is your typical 220v 2 leg system (L1 to ground and L2 to ground = 110 V, L1 to L2 = 220 V). I have at times used my adapters to hook to 30A services and 20A services with no problems. Of course, when one sees no problems, one tends not to notice details.
This weekend, I put on my 50 -> 30 amp and 30 -> 20 amp adapters and tried to plug into a friends GFI protected outdoor outlet. The outlet immediately saw a ground fault and opened the circuit at the outlet. There were no significant loads online in the MH at the time (no air, heating, etc). I'm wondering if something has gone wrong with my RV electrical system. I've plugged into 20A circuits before and have never seen smoke and fire but I don't remember if they were GFI protected circuits or not.
Any thoughts?
Yes lots of thoughts.
When I bought my RV, I had a portable 30 amp GFI, and it would trip when I tried to plug in the RV. So I ended up testing everything, and found that while the RV coach battery charger was unplugged, the GFI did not trip, yet plug it in, and it tripped right away.
Took the new RV back to the dealership, they had no solution, so basically gave away the GFI to a friend. I ended up installing a inverter/charger that was also not compatable with the GFI, and I can not plug in my RV to any GFI protected receptical anymore. (I have since wired the inverter/charger to one of the circuit breakers inside the factory panel, and can shut it off when I need to plug into a GFI protected outlet).
This has worked for me for the past 17 years.
My suggestion is to find the battery charger, and unplug it. Try the GFI again, and see if it holds. If it works, the microwave display lights up, TV works, ect. then try plugging in the battery charger. My guess is that will trip the GFI. At that point (if the GFI did not trip, but does once the charger is plugged in) then try plugging in the charger to a non-gfi protected receptical someplace else in the house, leave the rest of the RV loads on the GFI protected receptical.
Or another solution is find a non-GFI place to plug in. Such as the laundry room. Code requires a pair of 20 amp circuit breakers to feed the washer and dryer in modern houses. These are typically also wired 120/240, even though both are 120 volts, and on L1 and L2, similar to your RV wiring. If you measure top to bottom on the right hand side (with ground at the bottom) you will likely find it reads 240 volts. Anyway this is a dedicated 20 amp circuit breaker, typically without any other household loads on it.
Rule of thumb. If you are using the factory 30' RV cord to plug into the receptical, you can draw about 18 amps and not risk any overheating or shorted circuits, or trip the 20 amp breaker.
If you have to extend this with a 25' #12 gauge extension cord, you can still use about 18 amps, but should also expect to have a 3-6 volts drop in all those connections at 18 amp draw (only running the battery charger and 1 amp TV, the voltage loss will be less than 1 volt).
If you have to use a 50' extension cord, or something like a #14 gauge cord, then restrict amperage to less than 10 amps if possible. Meaning no 10 amp coffee maker, no 12 amp toaster, no microwave, no 14 amp air conditioner, you should consider running the 3 amp refrigerator on gas only. Your basic loads such as the battery charger should use about 1 amp, the TV and other electronics should use around 1 amp, and those loads are OK. Computers are normally less than 3 amps, while a laptop is typically 15 - 40 watts or less than 1/2 amp.
Fred.
