Please remember that, theory aside, the NEC now requires disconnecting means to open ALL 'hot' conductors. Likewise, you are required to have over-current protection on both legs of a 230 single-phase circuit.
All very true but we also need to remember that the float switch is a controller and need not open all conductors.
430.81 (A) Definition.
For the definition of Controller, see Article 100.
For the purpose of this article, a controller is any switch or device that is normally used to start and stop a motor by making and breaking the motor circuit current.
430.84 Need Not Open All Conductors.
The controller shall not be required to open all conductors to the motor.
I do agree with John I would rather the controller break all conductors.
