Neutral Wire

This is a subpanel in the garage. The wiring to the breaker is for a Carrier room a/c and heat wall mounted unit. Owner told me that the electrician wired the unit. The white wire is not connected. Shouldn’t the wire be connected ?

Not if it is 240 vac and red and black are used.


True if only 240 volt, but looks like some single pole 120 volt breakers. Got a picture of the whole panel?