Installation Fundamentals

Licensed electrician working on circuit breakers and heavy-gauge wiring in an open electrical panel being upgraded for EV charging station installation

EVSE Installation Process

This lesson covers the step-by-step installation process for Level 2 and DC fast charging stations, with emphasis on NEC Article 625 code compliance — the foundation of EVITP certification.

Critical Safety Warning

All electrical work must be performed by a licensed electrician. De-energize all circuits before working in the panel. Follow NFPA 70E arc flash requirements — wear rated PPE including insulated gloves and face shield for panel work. Never work alone on energized equipment.

NEC 625.22 — Branch Circuit Sizing (Critical for EVITP Exam)

EVSE is a continuous load — by definition, it draws current for 3 or more hours at a time. Under NEC 625.22, the branch circuit supplying EVSE must be rated at not less than 125% of the maximum continuous current draw of the EVSE.

Formula: Minimum circuit ampacity = EVSE rated amps × 1.25

EVSE Output	Voltage	EVSE Amps	Min Circuit Amps (×1.25)	Conductor (AWG Cu)	Breaker
3.8 kW	240V	16A	20A	12 AWG	20A 2-pole
7.2 kW	240V	30A	37.5A → 40A*	8 AWG	40A 2-pole
9.6 kW	240V	40A	50A	6 AWG	50A 2-pole
11.5 kW	240V	48A	60A	4 AWG	60A 2-pole

*When the calculation yields a non-standard breaker size, round up to the next standard size per NEC 240.6(A).

Visual reference chart for NEC 625 electrical conductor sizing showing wire gauge sizes, circuit breaker ratings, and recommended configurations — NEC 625 conductor sizing reference — wire gauge, breaker ratings, and recommended configurations for EVSE circuits.

Worked Example: A commercial site installs a 7.2 kW Level 2 EVSE at 240V.
Step 1: Determine EVSE current: 7,200W ÷ 240V = 30A
Step 2: Apply 125% rule: 30A × 1.25 = 37.5A
Step 3: Select conductor: 37.5A requires minimum 40A-rated conductor → 8 AWG copper
Step 4: Select breaker: Next standard size at or above 37.5A → 40A double-pole breaker
Result: 8 AWG copper on 40A double-pole breaker, 240V circuit.

NEC 625.54 — GFCI Protection Requirements

NEC 625.54 requires GFCI protection for EVSE in locations where there is elevated shock risk:

Outdoor EVSE: All receptacle-type EVSE outlets installed outdoors require GFCI protection.
Garages and carports: EVSE in garages, carports, and areas accessible from the exterior require GFCI protection.
Level 1 (125V 15A/20A) receptacles: All 125V convenience outlets used for EV charging require GFCI protection regardless of location.
Permanently wired EVSE: For hardwired Level 2 EVSE, consult local amendments — many California jurisdictions require GFCI on all outdoor hardwired EVSE.

GFCI trip threshold: Standard GFCI trips at 4–6 milliamps (Class A). If an EVSE repeatedly trips GFCI, do not replace the GFCI — investigate for ground fault on the circuit or within the EVSE.

Electrical wiring diagram showing path from utility meter through main panel, dedicated circuit breaker, conduit, EVSE unit, to vehicle inlet with color-coded conductors — Activity: Trace the wiring path from utility meter through panel to EVSE. Identify conductor gauge, breaker rating, and GFCI location.

Overcurrent Protection

Overcurrent protection for EVSE branch circuits must:

Be rated at 125% of EVSE ampere rating for continuous loads (matching the conductor sizing requirement)
Not exceed the ampacity of the branch circuit conductors
Be a dedicated circuit — no other loads may share the EVSE branch circuit
For 240V Level 2: use double-pole circuit breaker (both legs protected)

Pre-Installation Checklist

Permits and inspections coordination — obtain before work begins
Utility interconnection application (AHA-MACAV Power Service) — submit early, can take 2–6 weeks
Equipment procurement and staging — verify equipment is EVITP-eligible and CEC-listed
Safety plan and PPE requirements — arc flash calculation for panel work, rubber gloves for GFCI testing

Commissioning Sequence

Verify all wiring per as-built drawings

Check conductor size, breaker rating, GFCI presence where required. Compare physical installation against the design drawings.

Perform insulation resistance test (megger)

Test circuit conductors before energizing to detect insulation faults. This step prevents damage to the EVSE on first energization.

Energize circuit and verify voltage

Verify correct voltage at EVSE line terminals using a calibrated multimeter. Confirm both legs of 240V circuit are within 5% of nominal.

Activate EVSE

Complete network registration, payment system activation, and install required signage including ADA and charging instructions.

Test with known-good vehicle

Verify charging session initiates correctly, energy delivery is measured accurately, and the session terminates properly.

Final inspection and CEC documentation

Obtain electrical inspection sign-off. Complete CEC ARV-25-015 installation documentation including photos, as-built drawings, and test results.

EVITP Certification Path

This lesson covers material from EVITP Modules 3 (NEC Review) and 4 (Load Calculations). EVITP certification is administered by EVITP Inc. — the online course at evitp.org costs $275 and takes approximately 20 hours. Contact AMPS for information about exam fee assistance available for tribal members.

NEC Article 625 Quick Reference

625.22 — Branch Circuit Sizing: Circuits must be rated at not less than 125% of the maximum continuous current draw of the EVSE. All EVSE are continuous loads by definition.

625.54 — GFCI Protection: Required for outdoor EVSE, garages, carports, and areas accessible from the exterior. Standard GFCI trips at 4–6 mA (Class A).

625.44 — Equipment Connection: Covers cord-and-plug vs. hardwired connection requirements.

240.6(A) — Standard Breaker Sizes: When calculations yield non-standard amperage, round up to next standard size: 15, 20, 25, 30, 35, 40, 45, 50, 60, 70, 80, 90, 100A.