Is the following allowed by NEC?
• A main breaker panel is used as a main panel in a house.
• The hot wires from the meter go to a breaker at an arbitrary branch location on the panel thereby backfeeding the panel through this breaker. This breaker is clearly marked as "SERVICE DISCONNECT".
• The factory installed main breaker in the panel is not used but is not physically removed. Instead it is clearly labelled as something like "NOT USED".
Does the code allow backfeeding a main panel as opposed to a sub panel?
I understand that the backfeeding breaker would need to be fastened with a retainer, which brings up this question. Do they even make retainers that work with branch breakers in a main breaker panel? Or are the retainers only made for main lug panels where there is more of an expectation that the panel will be backfed?
The particular main breaker panel I have in mind is this:
GE PowerMark Gold 200-Amp 32-Spaces 40-Circuit Indoor Main Breaker Load Center, Model # TM3220CCU2K
https://www.lowes.com/pd/GE-200-Amp-32-Spaces-40-Circuit-Main-Breaker-Load-Center-Value-Pack/1001089
Is there a means to clamp down a branch breaker on this panel?
The purpose of all of this is to be able to use a 200 amp main breaker panel on a 100 amp service while retaining the ability to easily upgrade to 200 amps later if need be.
I want to end up with a main breaker panel if and when I upgrade to 200 amp. I would prefer not to use a main lug panel.
I would much prefer not to disturb the factory installed 200 amp main breaker. However I would agree to temporarily remove it until it is needed if this was the only issue.
I do not want to spend money on replacing the 200 amp main breaker at the top of the panel with a 100 amp variant, if one is even available for this panel.
Putting another panel or a disconnect between this panel and the meter in order to limit the current to 100 amp is not an option for me.
The solution I described would be the most useful for me. I believe it is electrically sound, but I am unsure if it is up to code.