Bruno1

Can anyone tell me if there's a rule in NFPA79 consistent with UL508A 60.1. Basically 60.1 states that a main disconnect is not required in an industrial control panel IF the size and type of protection are and clearly stated and that a disconnect is required by the installer, noted on the electrical drawings.

I have a question regarding the need for a control power transformer in a control panel. I have a 230VAC 3 phase control panel that I'm designing. I need 110VAC in that panel for various items. Is there any reason why I can't pull the 110VAC directly from one of phases on the distribution block (fuse it of course) and the neutral side from the neutral distribution block rather than installing a control power transformer? I've seen other designs where  in  similar cases a control transformer (230VAC to 110VAC) was used. Does it have to do with separately derived neutrals or is the transformer not even necessary? Thanks  

The project is in the Northeast. I was mistaken on my original post, the supply is 230 VAC single phase.  So I can easily get 110VAC from that. What are the rules as to when a control transformer is required? Thanks again for the help.