371—4.21 (173) Electric light and power. 120/240 volt AC power is available in most buildings and outside areas. In the varied industries building 120 volt single-phase, 208 volt three-phase is available. Three-phase power is also available in other areas for special applications. All wiring must be safe and not create a safety or fire hazard. The chief electrician must approve all wiring in accordance with the National Electrical Code. Electrical service charges will be set by the Iowa state fair board and published in the current year’s premium book.