To save on wire, could I directly hook up a ground wire to Inverter AC lug and take it directly to a ground rod?
Sorry, this isn't the place to scrimp.
1. Are grounding and bonding the same thing?
Article 250 of the NEC covers the grounding and bonding of electrical systems. By definition, as well as by function, grounding and bonding are not the same thing. However, they do work closely together in a yin and yang relationship to help ensure safety in electrical systems.
2. What is grounding?
Grounding is the electrical system’s connection to the ground itself. Article 100 of the NEC defines ground as “the earth.” Section 250.4(A)(1) states that grounded electrical systems “shall be connected to earth in a manner that will limit the voltage imposed by lightning, line surges, or unintentional contact with higher-voltage lines and that will stabilize the voltage to earth during normal operation.”
3. What is bonding?
Article 100 of the NEC defines bonded (bonding) as “connected to establish electrical continuity and conductivity.” Bonding metal parts, such as enclosures and raceways, ensures that they are all continuous on an effective ground-fault current path (EGFCP) that references back to ground (earth). The EGFCP helps operate devices such as circuit breakers and fuses or ground-fault detectors in ungrounded systems.
In grounded systems, it is important to bond the equipment grounding conductors to the system grounded conductor to complete the EGFCP back to the source of electricity. The conductivity of the EGFCP is critical for protective devices to work properly. This speaks to why we scrape the paint from contact surfaces of metallic enclosures to make our electrical system bonding connections. Removing the paint, as required in Section 250.12, provides for a better connection and conductivity path.
In the 2020 edition of the NEC, the language “or bonded” was added to Section 250.12, which now reads “Nonconductive coatings … on equipment to be grounded or bonded shall be removed …” This further emphasizes that grounding and bonding are not the same but work together to ensure the safety of the electrical system.
