This is a surface metal raceway wiring method permitted by Article 386. It is often used when adding circuits in an existing building where it would be difficult to fish cables through the wall or ceilings of concrete. This is one of the easiest ways to accomplish the run to supply equipment. In this case the circuit was three-phase, 208V with an equipment-grounding conductor. The fitting, which would ensure that the raceway was connected properly, was missing. Section 386.21 covers the size of conductors, indicating that no conductor larger than that for which the raceway is designed can be installed in surface metal raceway. Section 386.22 covers the number of conductors or cables allowed to be installed in surface metal raceway. This rule says that the number cannot be greater than the number for which the raceway is designed. I couldn't find a table for this wiring method in the Code, and wondered if the four 10 AWG conductors would be allowed here. Should another Annex be added to the Code with the number of wires allowed in this type of raceway?