Grounding and Bonding for EV Chargers in Georgia

Grounding and bonding are foundational safety requirements for every EV charger installation in Georgia, governing how electrical systems manage fault currents and equalize voltage potential between conductive components. This page covers the technical definitions, mechanisms, common installation scenarios, and decision boundaries that apply specifically to EV charging equipment under Georgia's adopted electrical codes. Understanding these requirements is essential for any residential, commercial, or multi-unit property where EV charging infrastructure is being installed or inspected.

Definition and scope

Grounding connects electrical equipment to the earth, providing a low-resistance path for fault current to flow safely away from people and equipment during an electrical failure. Bonding connects conductive metal parts — conduit, enclosures, equipment housings, and structural steel — to each other and to the grounding system so that no dangerous voltage difference can exist between those surfaces.

For EV chargers in Georgia, both requirements derive from the National Electrical Code (NEC), which Georgia has adopted through the Georgia State Fire Marshal's Office and enforced via the Georgia Department of Community Affairs (DCA). As of the 2020 NEC adoption cycle active in Georgia, Article 625 specifically governs EV charging system equipment, while Articles 250 and 230 establish the overarching grounding and bonding framework that Article 625 installations must satisfy.

Scope of this page: This page addresses grounding and bonding requirements that fall under Georgia state electrical code as administered through local jurisdictions and the Georgia DCA. It does not cover federal government facilities, Native American tribal lands, or installations governed exclusively by OSHA's construction standards for temporary power. Adjacent topics such as GFCI protection are addressed at GFCI Protection for EV Chargers in Georgia, and general regulatory context for Georgia electrical systems is covered in the broader regulatory overview.

How it works

Grounding and bonding for EV chargers operate through a system of interconnected conductors and electrodes. The following breakdown identifies the discrete components:

1. Grounding electrode system — A copper or steel electrode (rod, plate, or concrete-encased electrode) driven into earth at the service entrance, establishing the reference point for the entire building's electrical system per NEC Section 250.50.
2. Equipment grounding conductor (EGC) — A bare, green, or green-with-yellow-stripe wire run alongside the circuit conductors from the panel to the EV charger. This conductor carries fault current back to the source during a ground fault, tripping the overcurrent device and interrupting the fault within milliseconds.
3. Grounding conductor sizing — NEC Table 250.122 specifies EGC size based on the rating of the overcurrent protection device. A 50-ampere breaker (common for Level 2 charger circuits) requires a minimum 10 AWG copper EGC, while a 100-ampere circuit requires 8 AWG copper.
4. Bonding jumpers — Metal conduit, junction boxes, mounting brackets, and the charger's metal enclosure must all be bonded together using listed bonding fittings or conductors. NEC Section 250.4(A)(4) requires that bonding eliminate objectionable voltage gradients on equipment surfaces.
5. Neutral-to-ground bonding point — The neutral conductor is bonded to ground only at the service entrance panel (the "main bonding jumper"), never at a subpanel or at the charger itself. Repeated neutral-ground bonds create parallel neutral paths and are a named NEC violation.

The detailed technical framework for how Georgia's electrical systems handle these connections is explained in how Georgia electrical systems work.

Common scenarios

Residential Level 2 installation (single-family home): A 240-volt, 50-ampere circuit from a residential panel to a wall-mounted EVSE requires a 6 AWG copper circuit with a 10 AWG EGC run in conduit. The metal conduit itself may serve as the EGC if installed with listed fittings throughout, per NEC Section 250.118. For outdoor installations, the EV charger enclosure must meet NEMA 3R or NEMA 4 rating — a requirement that intersects with weatherproofing standards covered at outdoor EV charger electrical enclosure Georgia.

Commercial parking structure (multi-tenant): A commercial installation with 4 or more Level 2 charging stations will typically feed from a dedicated subpanel. Each branch circuit requires its own EGC back to the subpanel. The subpanel itself must have its neutral isolated from the ground bar — only the main service panel carries the main bonding jumper. Inspectors in Georgia's local jurisdictions routinely flag neutral-ground ties at subpanels as a code violation.

DC Fast Charger (DCFC) installation: DCFC units operating at 480 volts, three-phase, introduce additional bonding complexity. The equipment grounding conductor for a 200-ampere, three-phase DCFC circuit is 6 AWG copper per NEC Table 250.122. Metal raceways serving DCFC equipment on concrete pads may require supplemental grounding electrodes if the pad is isolated from the building's grounding electrode system. DC fast charger electrical infrastructure in Georgia covers the broader infrastructure context for these installations.

Contrast — metal conduit vs. PVC conduit: When rigid metal conduit (RMC) or intermediate metal conduit (IMC) is used, the conduit assembly itself qualifies as the EGC under NEC Section 250.118(4)–(6), provided all fittings are listed and wrench-tight. When Schedule 40 or Schedule 80 PVC conduit is used, a separate insulated or bare copper EGC must be pulled inside the conduit, as PVC provides zero grounding continuity.

Decision boundaries

The following conditions determine which grounding and bonding approach applies:

• Conduit type — Metal conduit allows the conduit-as-EGC method; non-metallic conduit mandates a separate conductor.
• Voltage class — 120/240-volt residential circuits follow NEC Article 250 with Article 625 overlay; 480-volt commercial circuits add NEC Article 230 service considerations and may trigger utility interconnection requirements documented at Georgia Power utility EV charger interconnection.
• Panel location — Chargers fed from a subpanel require verified neutral isolation at that subpanel before inspection approval. Georgia AHJs (Authorities Having Jurisdiction) typically verify this during the rough-in inspection phase.
• Outdoor vs. indoor — Outdoor grounding electrode installations must maintain a minimum burial depth per NEC Section 250.53(G): ground rods require 8 feet of contact with soil; concrete-encased electrodes require at least 20 feet of reinforcing steel or bare copper.
• Existing buildings — Retrofit installations in older Georgia buildings may encounter ungrounded wiring systems (two-wire, pre-1960s construction). NEC Section 250.130(C) permits specific methods for adding a grounding path to existing ungrounded outlets, but the branch circuit feeding an EV charger must have a complete, continuous EGC regardless. EV charger electrical retrofit for existing buildings in Georgia addresses the broader retrofit planning process.

Permitting and inspection for grounding and bonding compliance follow the process described in the broader Georgia electrical systems framework, with final sign-off by the local AHJ confirming that all bonding conductors are installed, all connections torqued to listed specifications, and the grounding electrode system is intact and tested.

References

• Georgia Department of Community Affairs — Construction Codes
• National Fire Protection Association — NFPA 70 (National Electrical Code)
• NEC Article 625 — Electric Vehicle Charging System Equipment (NFPA 70, 2020 Edition)
• NEC Article 250 — Grounding and Bonding (NFPA 70, 2020 Edition)
• Georgia State Fire Marshal's Office — Electrical Safety
• U.S. Department of Energy — Alternative Fuels Station Codes and Standards