Looking for a single phase split bus load center No main required , and 100 amp is plenty big. about 14 to 24 circuits total is large enough (12+- on each) don't have room for a sub panel so I need the split bus to house the inverter circuits. Anyone know where I could find on of these
You can't put that in a new structure anyhow
While the rule of six (230.71) is not a dead letter (there are still cases in new construction where a panel lacking a main disconnect can be installed), the "split bus" type panels you speak of are no longer Code, as they violate 408.36, Exception 1:
408.36 Overcurrent Protection. In addition to the requirement of 408.30, a panelboard shall be protected by an overcurrent protective device having a rating not greater than that of the panelboard. This overcurrent protective device shall be located within or at any point on the supply side of the panelboard.
Exception No.1: Individual protection shall not be required for a panelboard used as service equipment with multiple disconnecting means in accordance with 230.71. In panelboards protected by three or more main circuit breakers or sets of fuses, the circuit breakers or sets of fuses shall not supply a second bus structure within the same panelboard assembly.
But, marine panelboards are totally different beasts
Marine electrical gear is a different creature from the household stuff you were initially thinking of, and a bit beyond the scope of this site in some cases. I'd talk with a specialist familiar with the subtle hazards AC on a boat poses if I were in your shoes -- electric shock drowning hazards are brutal.
An antique shop
Split-bus panels are obsolete, kinda dangerous, and a rich environment for code violations. They're obsolete because the "rule of six" has gone by the wayside. It was hopeless; homeowners and handymen not knowing any better would routinely slap a single or even tandem in the top 12 spaces, violating the rule of six. They're dangerous because consumers don't know how to de-energize them. How do you turn off power when there's no main breaker? "Turn off all the breakers in the top 12 spaces" is insanely non-intuitive regardless of labeling.
The reason to do them was cost -- split bus panels were half the price because big main breakers were expensive. Not anymore. The rate these panels caused trouble was not worth it.
I do note its potential value for switching generators; put the interlocked shoreside and generator breakers in the top 4 spaces of the lower area. The problem is you're then putting all non-generator loads in the top 12 spaces, and on a house, that will take a lot of cram, and you'll inevitably violate the rule of six. It might work if you had a main breaker outside as part of the meter pan or shore service, and this was already a subpanel.
But no-one will sell you a new one. So you will need to scrounge it.