Requirement for electrical installations

Electrical installations shall be planned to provide adequate capacity for the load. 1. Wiring systems shall have conductors of sufficient capacity to furnish each outlet without excessive line loss or voltage drop. The voltage drop shall not exceed five percent at the farthest outlet of power, heating and lighting loads, or combinations of such loads. (See appendix for example.) 2. All wiring materials and equipment shall be listed by nationally recognized testing laboratories to safeguard life and property. It is the duty of the electrical installer to secure permission from the executive director to use materials, devices, and methods of installation not specifically covered by these standards. Equipment not approved under a testing laboratory category shall be evaluated by a registered professional engineer and recorded on evaluation forms accepted by the board. Exception: Manufacturing firms that install industrial machinery for use by the firm itself and employ professional engineers may evaluate the industrial machinery according to NFPA 79 or UL 508 Standards. This evaluation shall be maintained with the equipment at all times and a copy submitted to the board. 3. When wiring public school buildings, approval shall be received from the department of public instruction and the board. 4. Overhead conductors shall not cross over water wells or known sites where water wells may be drilled. A minimum distance of twenty feet [6.10 meters] in all directions shall be maintained for overhead conductors. 5. In the wiring of nursing homes and hospitals, reference shall be made to the state department of health for special requirements pertaining to operating rooms, delivery rooms, and emergency lighting. 6. Aluminum or copper-clad aluminum conductors in sizes smaller than no. 6 must be used only for class II and class III circuits. 7. All new construction shall follow the energy-efficient related requirements for design and construction of buildings in accordance with the locally adopted codes or the State Building Code. 8. In any room of an existing building where the sheetrock or wall covering has been removed from all walls, the electrical wiring requirements must comply with the 2026 edition, National Electrical Code (first version, printed in 2025). 9. If the occupancy of an existing building or part of an existing building is changed, the electrical wiring and equipment of the building or portion thereof that contains the proposed occupancy must comply with the 2026 edition, National Electrical Code (first version, printed in 2025).