What are the minimum requirements for white conductors in service?

The minimum requirements for white conductors in service are that they must be clearly marked when used as a phase conductor. This designation is due to the NEC guidelines that specify how conductors should be identified to ensure safety and clarity in electrical installations. Since white is typically designated as a neutral conductor, using it as a phase conductor can lead to confusion. Therefore, marking it clearly avoids misinterpretation and maintains the integrity of the electrical system, ensuring that all personnel can readily identify the purpose of the conductor being used.

The rationale behind marking is to comply with safety standards while maintaining the recognition that some installations might require white conductors to be repurposed for phase applications, particularly in multi-wire branch circuits or specific situations. The requirement for clear markings is vital in preventing accidents and ensuring that those servicing the equipment can safely distinguish between different types of conductors.

The other options misrepresent the regulations in some way. Avoiding white conductors in service applications is not a requirement per se, as they can be properly utilized when marked appropriately. The notion that they can never be used as a phase conductor disregards their permissible use when proper identification is applied. Suggesting they be colored red is unnecessary and does not align with the NEC's requirements for marking and identification