So obviously of panel UP-B&C are 3P4W panels it would require a neutral wire?
You are correct but it actually only 'Requires' a neutral wire if the panel is serving line to neutral (120V) loads. If the panel does not have any of these it serves no purpose. However I do not recommend not providing the neutral wire even if it does not supply 120V circuits because anyone looking at the panel nameplate in the future could 'assume' it is provided. Trust me I've been burned on that one in the past. Now I always confirm it exists.
