here is my power control/safety system.  postive from the battery connects to the breaker.  the breaker is connected to the contactor via a fuse.   the breaker is rated for 313 amps at 160 volts, the fuse is 400 amp and the contactor is an albrite 200.  the breaker is deactivated via pulling the clutch.  the contactor is controlled via the off/run switch [located for the right thumb as is common].