I have very little info, so I will provide what I have. My house has a line out of it's breaker box (double pole, 200amp breaker) that runs about 250 feet to a breaker box inside a pole barn. Where it comes into the barn is short of where I need it to come into the barn. Long story short, I am building a living space in the BACK of the barn and I don't want to run all my electrical to the front of the barn when I could potentially just extend the inbound line from where it is (inside the barn) to the back where I need it. Facts: The house only has one meter (this may be irrelevant). The line to the barn is direct bury 4 lead line which is gray in color. Hopefully someone can identify it, and I can probably get pictures of where it goes into the barn box if we need it. Here is what I need to know: 1) How many amps is that direct-bury line able to carry? 2) What kind of junction box (is that the way to go?) do I need to put where the barn breaker box is in order to begin extending the location of that box? 3) What kind of line do I use to extend the barn box once the junction box is in place? 4) Am I even thinking about this the right way? Thanks in advance for your feedback, I really appreciate it!

I have a propane fired boiler that requires a pure sine wave energy signal. Very efficient unit but worthless when I lose power. It won't fire when the house is running on my portable generator. Question is, is there an AC to AC inverter for this purpose? I have only been able to find DC to AC units for this. I want to keep this simple for my family. They have enough issues pulling out the portable and plugging it into the house when I am not home.