I have a new air compressor for my hot rod fabrication. The specifications are as follows,
5.5hp 80gal 24amp 240v. My question is, it calls for a 30 amp breaker and time delay fuse, Type "T". I am running 6/2 wire to supply the unit, it is about 90 ft from the main panel so we ran 6/2 for minimal voltage drop and heat distribution. Do I use 30 amp 125v fuses for each leg, or do I need 30 amp 250 fuses for each leg ? Also any recommendations for type "T" fuses at this rating as well as a disconnect box to house the fuses. Need to start grinding! Any info will be GREATLY APPRECIATED. Thanks

Where are you located?
Why Class T fuses?
Also you state circuit breaker and fuse. Either or is required.
Where is the unit made?

If located in the US, motors need to be protected by a time delay device due to starting current per Table 430.52 of the NEC 2002 edition, since 5.5 HP is not listed in the code, a fuse can be 175% of nameplate running current, and a breaker can be 250 % higher.

Since the voltage is 240 volt, then Class T fuses are not required, as they are rated for 600 volts. Fuses generally come rated 250 & 600 volt, so Class RK1 should be fine, which is very common.

However, a circuit breaker will be fine also, and only will need a non fused switch at the unit for a service disconnect. And no need to have spare fuses on hand.

So a 5.5 HP motor drawing 24 amps at 240 volts can use a circuit breaker no larger than 60 Amps. If you are certain to use fuses, then a maximum of 50 amp fuse will work. Do not put too small a fuse, I would not use a 30 amp device to protect 24 amps of motor load,since the starting current of 150 to 300 % may cause the fuse/breaker to trip often,esp if the unit starts/stops often.

Oh and good choice on the cable size for the right reasons

Thank you for your response. Very informative, helped me greatly. One more question, what is the difference between Rk-1 and Rk-5 fuses? Thanks again

The Class of fuse is a designation deterimned by Underwriters Laboratories.

The difference between RK1 & RK5 has to do with the time to clear and the maximim peak current let through of each Class.