What I am looking for is guidance and honest evaluation. I'm not afraid of being wrong. I want to save some bucks and learn some things, without blowing myself up. So please tell me if I'm doing something dangerous, and preferably please tell the section of the code I'm violating.
OK, so I have a cabin in the boonies. Right now there is a pole with a transformer on it that is connected to a meter. Below that is an old box that is going to come out. I met with the rep from the POCO, and here is the culmination of what I remember discussing with him, and my own independent research.
Here is my attempt at explaining my cheesy diagram.
A) So the POCO comes in with 14.4 kV. The transformer steps this down to split phase 240V, delivering two 120V hots and a neutral to the meter base. The transformer neutral is bonded to a ground wire running to the base of the pole. Out of that meter base we come into my wiring. I provide a 100A main lug panel.
B) On that main lug panel are two breakers, a 100A and a 20A. The 100A goes to the house. The 20A goes to a rarely used outdoor GFCI receptacle. The main lug panel has the neutral bonded to the POCO's ground wire. This is the ONLY place in MY wiring where the neutral is bonded to ground. After this point the ground never touches the neutral.
C) Out of the main lug panel we go through underground triplex 1/0 cable to my house panel. I've calculated the voltage drop to about 4.91V at full 100A (which I'll never use), and the POCO rep told me this was perfectly acceptable, and that this was the right cable to use.
D) In the house we come into a 100A main breaker panel, with various breakers etc. The neutral is NOT bonded to ground here, and the ground goes to two ground rods 6 ft apart.
E) From here we run 10/3+ground out to the shed which we treat simply as a multiwire branch circuit, since there's no panel out there. Note that one neutral is run, and both breakers are mechanically connected to disengage if either one disengages
- Inside the house I run EMT conduit, and at every opportunity I attach the green wire to the conduit or metal box.
- In all circuits I plan to use AFCI breakers.
- I figure that two 100A breakers in series is fine (there's still no way that I can exceed 100A. Am I wrong?
- I worried that I screwed up at the pole. Do I need to lose that 20A breaker & receptacle? Or use a 70 and a 20?
- Is my grounding correct at the house? Why or why not?
Thank you very kindly for any help and guidance.
- number 6 bare copper ground wire added to underground run from pole and terminated in ground bar of house and ground bar of pole (which is bonded to neutral at pole)
- changed shed circuit to 10/2 plus ground, and run the neutral through the GFCI
ALSO: I can lose the 20A GFCI at the pole. If I need power up there I can just haul the generator up there.