I have a job installing new luminaires on 17 light poles in a city park and installing new in-ground wiring to the poles. The new luminaires are LED with a listed current draw of 520 milliamps each, with universal power supplies listed at 120v-277v. The city also wants to place an approximately 8 amp, 120v gate operator at the end of the conduit line feeding the poles from the panel, using the same wiring as the light poles. The conduit run is approximately 1200' long. Their design shows the system wired with 5 #2 conductors: 2 hots, 2 neutrals, one ground. The design is for all luminaires to run at 120v, with 7 of the light poles and the 8 amp 120v load on one 20A single pole breaker, and the other 10 light poles on another 20A single pole breaker. The final piece of the puzzle is the light poles are pre-wired with #10 solid THHN/THWN and have in-line fuses at the base of the poles which then will tap into the main #2 lines in an in-ground hand hole next to each light pole. Seems reasonable. The problem is the existing conduit is old and only had 4 conductors originally (no ground). Pulling the old wire out was pretty difficult in a couple of the segments even with our 8000# tugger, so I would like to keep the diameter of the new wire bundle we pull in about the same as the old one if possible. Is there any reason this setup would not work as a 240/120v 4 wire multi wire branch circuit (3 wires plus ground)? The 17 luminaries would all run at 240, and the neutral would only be used for the 120v operator at the end of the line. Instead of 2 single pole breakers, there would be one 240v 2pole breaker. It seems like this should meet code, but I'm always confused as to why NEC 210.4.C says "line to neutral loads only" but then has exception #2, which seems to say the same thing as 210.4.B. Any help from you smarter people is greatly appreciated!