Is it okay to use 30A fuses in a disconnect switch on a 20A circuit if the disconnect switch is not there to protect anything--just for convenience? The fused disconnect was just cheaper and more available at my local hardware store than a non-fused disconnect. My thinking is that the 20A circuit breaker protects all the 12/2 wiring and the tools are fine on their own. If something should trip the breaker (nothing has thus far on circuit) 20A fuses would or could just need replacing for no real reason--that's why I initially got the 30A fuses.

Some more details in case they affect answer. I'm running 12/2 wire for my new table saw by extending an existing 20A 220v circuit for my jointer (all wire is 12/2 and breaker is 20A DP). Table saw and jointer will be only tools on circuit and will not operate at same time as it's just me in my basement shop. I bought a "Light Duty" 30A fused disconnect (Square D L211N). It won't be the primary disconnect as the saw plugs into an outlet (L6-20P/R). The switch is just so I can cut off the power to the table saw (not turn it off) with a switch rather than unplug it for changing blades or making adjustments and maybe a lockout point for children as they get older. Mismatching the 30A fuses with a 20A circuit seems odd (maybe a NEC code violation?), but putting 20A fuses in seems redundant with the circuit breaker since I don't really want/need them to blow to protect anything. As I type this I think that maybe 20A fuses would "backup" the circuit breaker, but is that necessary or practical? Would the 20A breaker trip before 20A fuses (type TL) would blow?

Thanks for any advice or suggestions. -Rick