Unloader valve failure. The pump is trying to start against tank pressure. Fix: Listen for a "hiss" when the motor stops. That hiss is the unloader releasing pressure. No hiss = bad unloader. Clean or replace it.
Most units ship wired for 110v. This is rare for a cast-iron 2HP motor. However, pros note: If you wire it for 220v, the amperage draw drops, the motor runs cooler, and you reduce voltage drop on long extension cords. hurricane 21510 compressor
If you treat it right, it will be the last compressor you buy for your home shop. If you abuse it, it will forgive you—just change the oil first. Unloader valve failure