A few very general observations/opinions…
  • Unlike low-voltage systems, a limiting factor is usually voltage drop and not cable thermal capacity
  • Source characteristics — Usually 600 amperes is the limit for an entire/single MV distribution feeder. 600 amps is equivalent to ~29,000hp
  • Regarding drive front ends — Will they have 6-, 12-, 18- or 24 pulse rectification? You can look at harmonic mitigation from a purely economic standpoint.
  • UG versus OH cable characteristics {and losses} make them respond differently to harmonics.
  • Will there be any foreseeable loads in addition to VFDs/motors
  • Suggest that a distribution engineer experienced in industrial applications be retained to conduct loadflow studies for various line arrangements/loads.

[This message has been edited by Bjarney (edited 07-29-2004).]