DDell,
At startup the compressor is putting a 276 Watt load on the invertor. Depending on the efficiency of the invertor the invertor is putting some figure more than that on the power lead going into it. Less than 500 W. But first figure what you need to deliver 500 W to the invertor. Since this is coming in at 12V the delivery in Amps could be as high as ~ 42 amps (500 W). You may only need around 325 Watts of delivery to the invertor if it 85% efficient. (Less if more efficient). So 325 Watts requires 27 AMPS and, were it me, I would want to be sure the disconnect can handle 30 amps (preferably 40).
You have two 100 Watt Panels, this is enough for when the motor has already been started but it is insufficient to start the motor. So consider adding a 12 volt battery. It should be connected between the leads of the buck converter (on the output side of the converter). What this will do is provide storage for power which will supply the excess needed for startup. Once the compressor is started, the panel will charge the battery to the extent it delivers power in excess of the load of the inverter/compressor.
I am not sure if you omitted the battery over concerns of theft or if you were hoping to lessen the cost/maintenance of the system (being content with only daytime operation). But the battery, given only two solar panels, is essential for the system to work. The startup load is the reason you need it. A bonus is storage of excess power and operation when the sun is not shining (even during the day when clouds obscure the sun). I consider nighttime operation a bonus but if you prefer it not to operate at all at night you could incorporate a timer. Without, a battery, it would require 4 panels, a larger or additional converter, and full sun to start the compressor.
