I want to add an RV subpanel to our cabin, but the location where I want it is very close to the main service switch, but pretty far from the circuit panel inside the cabin. Currently, there is about 100' of underground wire (I think it's MCM 250 aluminum) feeding into the cabin. What I want to do is put in a subpanel, but connect it to the main supply feed (but after the service disconnect switch).
I was thinking that I could use a tap to pull a 6ga wire off of the MCM 250 inside the service disconnect and run that (through underground conduit) to the RV sub panel. I'm having trouble finding out if that is legal though. I was going to put a 4x4 pressure treated post in the ground and mount the sub panel to that, and run the 6ga wire underground through the conduit to it.
Here's a picture of what I have in mind:
You can ignore the generator part of the diagram for now, unless you want to comment on what I have in mind (putting the ATS right below the service switch about 20-25' from the generator).
Is what I have in mind here kosher? Or do I need another main cutoff switch before the RV sub panel?
One of the main questions I have is if I can tap on the switched (after the main 200a breaker) side of the main service switch using something like a "Morris 97643 Multi-Cable Connector", then run the tapped wire off to a sub panel. Since the main service switch would switch off both the circuit breaker in the cabin as well as the sub panel, I'm wondering if that is ok.