Kill My Dreams! Repurposing Hot Tub Sub-panel for Grid-Tie System? AC Disconnect?

[JoelE]

This is my first post and I'm a newbie with high hopes prepared to have my dreams crushed by the impending waves of code violations you are about to find with my plan... I want to keep this simple for myself and I don't even want to touch my main panel at all if I can avoid it. I own the home and want to do my own install, including the electric. I was certified in the Oregon Green Tech program and have done some NFPA 70E training. I'm not officially a 'qualified person' so I'm not sure if they'll even let me do the install here in Oregon... Unless there's a 'qualified person' out there who wants to let me demonstrate to them that I'm qualified (for the very narrow task of a basic solar install?) But I digress...

My setup is like this:

• 200amp Panel (WITHOUT A MAIN BREAKER)
• Existing 50amp breaker at the panel for Hot Tub (no longer used)
• External Sub-panel for Hot Tub, currently with a 30amp and a 20amp breaker (no longer used)

The system I'm designing is like this:

• 9.8 kW across 22 panels (2 strings of 11)
• 7.6 kW inverter w/ Tigo transmitter
• 22 TS4-A-F
  • Side note: I had a small freak-out today worried that my stupid MC4 connectors would not match for my Rapid Shut Down system because my panels use MC4-EVO2 and Tigo's are MC4, but apparently they still quality as a matched system because they are the same manufacturer and type.

My plan is like this:

1. Remove the 30AMP and 20AMP breakers from the hot tub sub panel, and insert a 40amp breaker and a cover where the 20amp was.
2. Install my AC disconnect switch below the sub-panel connected to the 40amp breaker. I guess I need a zip-tie to close it?
3. Install my Inverter to the left of the AC disconnect, with the rapid shutdown switch located to the left of that and then up to the panels on the roof
4. Done (after I attach a ton of red stickers according to their most useful purposes)

I want to know if this qualifies under this method - Meaning I don't have to care about where the breaker is located because it is already installed and already under the 200amp panel rating:
:

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I'm hoping it also means I don't have to do a supply side tap or replace my whole panel with a new one with a main breaker? After all, I'm literally not so much as touching the main panel, other than to ensure the breaker is off for the hot tub circuit and to properly label it.

My questions are:

1. Will this work, and if not, can you point me to the specific reference that precludes it?​
2. Am I right to assume I still need an AC disconnect, even though the breaker box is right there and would serve the same function?​
3. Am I OK to put the 40amp at the sub-panel while the panel itself is 50amp? The wire is at least 8 AWG. I figure keeping it at 40amp is still the correct size for my 7.6kW inverter (it is rated at 32amp max), and if anything it just ensures me more headroom at the main panel than I had with the hot tub.​

 

[MajicDiver]

Your #1: I am doing something functionally the same as what you propose. Anyone who adds loads to a panel in the future should consider what’s already there IMO.
Your #2: “right there” can mean different things, but that’s what I’m doing.
Your #3: you got to be absolutely sure what your wire size is and type. Can’t be guessing. Especially if you don’t know why it’s no longer used.

I’m not an electrician and don’t know code very well - you can follow codes to the letter without thinking and really mess up.

 

[JoelE]

Your #1: I am doing something functionally the same as what you propose. Anyone who adds loads to a panel in the future should consider what’s already there IMO.
Your #2: “right there” can mean different things, but that’s what I’m doing.
Your #3: you got to be absolutely sure what your wire size is and type. Can’t be guessing. Especially if you don’t know why it’s no longer used.

I’m not an electrician and don’t know code very well - you can follow codes to the letter without thinking and really mess up.

Thanks!
I will absolutely confirm the wire gauge is either 6 or 8AWG. I know it's no longer used only because I'm the homeowner and I know the hot tub has been decommissioned - No problems with this circuit.

For the sake of having it more easily accessible since this breaker box is a bit high, I will go ahead and add an AC disconnect below the sub-panel.

I still need to figure out if my 'split bus' MSP will make it through inspection for this... It's an obsolete MSP.