On a 4-wire, delta-connected system, where should the orange marking be placed?

In a 4-wire, delta-connected system, the color markings for conductors serve to identify their phase voltage levels. The National Electrical Code (NEC) provides guidance on this, specifying the use of color coding for phase conductors to ensure safety and clarity when working with electrical systems.

The orange marking indicates the conductor that is associated with the higher phase voltage to ground. In a delta configuration, while there are no dedicated neutral conductors like in a wye configuration, it is essential to identify which phase conductors might present higher voltages. This identification helps in avoiding accidental contact with higher-voltage conductors during maintenance or troubleshooting, enhancing overall safety for workers and equipment.

Marking the higher phase voltage to ground with orange serves a practical purpose in establishing clear identification of the electrical system's components, allowing electricians and technicians to quickly recognize voltage levels and adhere to safe practices when interacting with these wires.

The other options do not represent the correct placement of the orange marking, as they either refer to lower or neutral connections that do not align with the NEC's guidelines on marking conductors in a delta configuration. Thus, placing the orange marking on the higher phase voltage to ground underscores the importance of safety and compliance with code requirements in electrical installations.