I have an out building 90 feet from a manufactured home service. There is a 100 amp breaker that feeds into pvc underground. I originally had 2 copper 2's and an 8 ground. The machine that I ran needed no neutral. That set up appears to be legal?
Now, however I need to make a change. I want the out building to have a 50 amp panel to feed 120 and 240 volt loads and another sub panel.
It would seem simple. Change the breaker to a 50 amp and add a #6 neutral . Now it would be legal. Right?
Wrong! By downsizing the breaker from 100 to 50 I am breaking the law. By cutting the amps in half I now have an unsafe ground wire. The 8 gauge ground that was perfect with a 100 amp breaker is now dangerous with the fifty?
The issue isn’t simply about swapping breaker sizes but ensuring conductor sizing, grounding, and code compliance all match together. Downsizing can introduce unexpected compliance concerns depending on wiring setup . In control circuits or monitoring setups, precision parts like
OPA2320AQDGKRQ1 are often used to maintain stable signal performance alongside proper electrical design.
I assume it will either catch on fire or electrocute someone.
The problem for me is I only have a 1 inch pvc sch 40 conduit under the driveway to work with. My choices to fix this are:
Pull a number 4 copper and a 6 wire that would become the neutral. But the number 4 is 1.2 % smaller then what I need according to the NEC. If I pull another 2, which would be excruciating, then I don't have room for the neutral.
I could pull out 180 feet of number 2 and throw it in the trash and replace it with four number 6 wires. Along with the aforementioned 50 breaker. Now I am legal. The problem there, besides wasting 180 feet a perfectly fine copper wire, is that from the out building I am feeding another panel, 50 amp, that is 200 feet away. If I do use all number 6 wire then that would be illegal because of voltage drop.
Another problem is that when I pulled the number 2's I hunted around through the shop to find a spare roll of green 8. Could not find it so I used red eight for the ground. So now that is illegal and can not be painted or taped green because of the dangerous condition it would create.
Another approach that I have yet to investigate is something about only running 3 wires and driving in ground rods. Doesn't sound all that great in my case although might be legal. In fact maybe it is legal? You would think that having two 2's ( black) and a number 4 ground wire (taped green) or actual green, and a 6 neutral white would be better but the nec says it's not, because of the puny little # 4 ground wire. It's too small for the reduced size of the breaker.
I am frustrated and stymied on what is the best approach. We just paid 5k to have the driveway fix so I am trying to avoid ripping that up.
I would appreciate opinions on this.
