Field Guide • Service & Energy
How to Install a Commercial EV Charger
Updated July 21, 2026 • Written by the field team at Arizona Electrical Solutions. All field guides →
Commercial EV charging is now a standard scope line on retail, office, and multifamily jobs, and Article 625 owns it. The electrical fundamentals are friendly — an EVSE is a big continuous load with clean sizing rules — but the details decide whether the install survives: load calculations against a service that wasn't built for it, the 2023 load-management allowance that often saves the project, and site work where a bollard matters as much as a breaker.
This guide covers Level 2 commercial installs — the 30 to 80 A, 208/240V workhorses — with notes on where three-phase DC fast charging changes the rules. It pairs with the site-assessment conversation every owner needs before promising chargers on a marketing plan.
Safety first. This work is for qualified, licensed electricians only. De-energize the supply, apply lockout/tagout, and verify absence of voltage with a tester proven on a known live source before working in panels or EVSE terminations. EVSE units contain stored energy and contactors that operate automatically — follow the manufacturer's service procedures. Site work near parking areas needs traffic control and barricades. Pull the required permits — many jurisdictions have dedicated EV-charger permit tracks — and remember the locally adopted NEC edition and any local amendments govern; this guide references the 2023 NEC.
What you'll need
- EVSE units, listed (UL 2594 for Level 2), with mounting hardware and the manufacturer's install manual
- Conductors sized at 125% of the EVSE rating — THWN-2/XHHW-2 for outdoor raceways
- Two-pole breakers per unit sized per 625.41 and the manual
- Load management system / EMS hardware or software licenses where the design uses 625.42
- Concrete pedestal or wall mounting per the site plan, plus bollards where vehicles can strike
- In-use covers and wet-location fittings for outdoor terminations
- Signage: accessible-space markings and 'EV charging only' per the site plan and local code
- Torque tools, megger, and the commissioning app/account the EVSE brand requires
Code references
| NEC 625.41 | EVSE circuits sized for continuous duty — OCPD and conductors at not less than 125% of the maximum load. |
| NEC 625.42 | 2023 allowance: with an EMS per 750.30 managing the EVSE, the service/feeder load is the EMS maximum, not the nameplate sum. |
| NEC 625.17 | Output cable length limits — the rule that makes pedestal placement relative to the charge port matter. |
| NEC 625.54 | GFCI requirements for receptacle-connected EVSE — a reason commercial installs hardwire instead. |
| NEC Article 750 | Energy management systems — the listing and control basis behind the 625.42 allowance. |
| NEC Table 300.5(A) | Burial depths for the parking-lot conduit runs, including 24 in. under drive aisles. |
| NEC 110.3(B) | The EVSE manual's settings, breaker requirements, and mounting instructions are enforceable conditions of the listing. |
Section numbers follow the 2023 NEC; the edition adopted by your jurisdiction governs.
Step by Step
How to Install a Commercial EV Charger
1. Start with the service, not the charger
Every EVSE is a continuous load — Article 625 treats it as continuous by definition, so branch circuits and feeders size at 125% of the maximum load per 625.41. A 48 A charger needs a 60 A circuit; a 40 A charger needs 50 A; eight 48 A chargers need 480 A of capacity if nothing manages them. Run the Article 220 service calculation before promising charger counts — on existing buildings, the panel schedule fantasy and the meter's reality often differ, and a recording ammeter study of actual demand is worth a week of data before committing.
This is where the 2023 changes earn their keep. 625.42 allows the service and feeder sizing to follow an energy management system's setpoint instead of the sum of nameplates: an EMS per 750.30 that caps the combined draw lets you install more plugs than the raw capacity supports. Eight 48 A chargers managed to a 200 A ceiling legally live on 200 A of feeder capacity — the EMS setpoint becomes the load for calculation purposes.
Decide the management strategy up front: standalone EVSE with fixed settings, networked chargers sharing a circuit-level cap, or a site-level EMS. It changes the gear you buy, the conduit you run, and the load letter you write.
2. Size the circuits and set the units
Per-unit sizing is mechanical: EVSE maximum load × 125% = minimum conductor ampacity and OCPD. Most commercial Level 2 units are adjustable — a unit settable to 48/40/32 A gets sized for the setting you commission it at, and the setting must be made per the manufacturer's instructions (usually internal DIP switches or software, and 110.3(B) makes the manual binding). Document the setting; a future tech bumping a 40 A unit to 48 A on a 50 A circuit creates a violation with a phone app.
Voltage drop matters more than usual: chargers live at the far corner of parking lots, runs of several hundred feet are routine, and a charger is a full-load continuous appliance for hours. Size for 3% or better at full output — upsizing aluminum feeders to remote pedestal clusters is standard practice and cheap compared to copper.
Check the EVSE's internal protection before adding external GFCI: hardwired Level 2 units include listed charging-circuit interrupting devices (CCID) as part of UL 2594, and most manufacturers prohibit upstream GFCI breakers because the two devices nuisance-trip each other. Where a receptacle-connected unit is used instead, the receptacle GFCI rules of 625.54 apply. Hardwire commercial installs; it avoids the whole question and the vandalism-prone cord cap.
3. Run the site work like site work
Parking-lot chargers are an underground project: trench or bore to the pedestal locations per the burial-depth rules of Table 300.5(A) (24 in. under drive aisles), stub up inside the pedestal footprint, and pour bases per the manufacturer's template with the conduit placement exact — pedestal bases have tight conduit windows, and a stub two inches off means core-drilling a fresh base. Set bollards or wheel stops wherever a vehicle can reach the unit; 110.27's physical protection expectation is real, and a nose-in parker will find any unprotected charger within a year.
Mount wall units at the manufacturer's height, with the connector and cable management reachable from the parking space — coordinate accessible spaces early, because accessible EV spaces have their own mounting-height, clear-floor-space, and route requirements under the accessibility codes, and retrofitting compliance is expensive. Cord length is capped (625.17 limits the output cable), so pedestal placement relative to the charge port side of a parked car actually matters; place for the plug, not the site plan's aesthetics.
Outdoor terminations get wet-location fittings and in-use covers, and Arizona sun cooks cheap plastics — spec UV-rated everything and shade pedestals where the layout allows. A charger screen that dies at 140°F is a warranty argument; a melted cord grip is a hazard.
4. Wire the EMS and networking where the design uses them
If the project leans on 625.42's load-management allowance, the EMS is now code-relevant equipment: its setpoint is the number your service calculation stands on, so its configuration is part of the inspection story. Wire the current-monitoring CTs and communication paths per the manufacturer — typically CTs at the feeder or service, and either hardwired RS-485/Ethernet daisy chains or cellular/Wi-Fi links between chargers. Hardwire where you can; parking-lot Wi-Fi is a service-call generator.
Networked chargers also carry the operator's requirements: OCPP backend enrollment, payment systems, utility demand-response programs. Confirm who commissions the network layer — the electrical contract usually ends at 'charger online and communicating,' but that line must be drawn in writing before the owner assumes you're the software integrator.
Leave the load study and EMS documentation with the panel schedule: the setpoint, what it protects, and why it must not be raised without recalculation. That one-pager is what keeps the next contractor from quietly breaking the basis of the installation.
5. Commission and hand over
Before energizing: megger the feeders and branch circuits, torque-verify every termination including the EVSE power blocks, and confirm the unit's current setting matches the circuit. Energize and commission per the manufacturer's app or procedure — modern units self-test their CCID, contactor, and pilot circuits and won't deliver power until they pass. Verify a real charge session on each unit with an actual vehicle or a test load, at full current, and watch for voltage drop under load at the farthest pedestal.
Walk the operational details with the owner: breaker locations and labeling, how the EMS sheds load and what users see when it does, the manufacturer's maintenance schedule (cord and connector inspection is the big one), and who answers the support line. For fleet and multifamily sites, set expectations about charging speed under management — a managed 48 A charger delivering 20 A at peak is working correctly, and the owner should hear that from you, not from an angry tenant.
Close out the record: as-builts with conduit routes, the load calculation and EMS setpoints, commissioning reports from the app, and photos. EV infrastructure grows — the next phase starts from your documentation.
Watch Out
Common mistakes
- Selling the owner eight chargers off the panel's label without a service load calculation or demand study
- Sizing a 48 A charger's circuit at 50 A — forgetting the 125% continuous factor needs 60 A
- Adding a GFCI breaker ahead of a hardwired unit whose listing prohibits it, then chasing phantom trips
- Setting pedestal bases with the conduit stubs outside the manufacturer's tight base window
- Ignoring voltage drop on 400 ft runs to the back of the lot and delivering slow, complaining chargers
- Leaving chargers unprotected from vehicle strike — no bollards, no wheel stops
- Raising a unit's current setting in the app without touching the circuit that feeds it
FAQ
Frequently asked questions
Why is EV charging always a 'continuous load'?
Article 625 defines EVSE load as continuous for sizing — a charging session runs for hours at full current, exactly the sustained-heating case the 125% factor exists for. So a 48 A charger needs a 60 A circuit and conductors with 60 A of ampacity after corrections.
How does load management let me install more chargers than the service supports?
2023 NEC 625.42 allows the calculated load to be the energy management system's ceiling instead of the sum of nameplates. The EMS monitors and curtails the chargers so their combined draw never exceeds the setpoint — and that setpoint is what your feeder and service must support. The trade-off is slower charging at peak occupancy.
Level 2 or DC fast charging for a commercial site?
Level 2 (208/240V, 30–80 A) covers workplaces, retail dwell-time, and multifamily overnight charging at reasonable install cost. DC fast charging is a different project — three-phase supply at 50–350 kW per unit, utility coordination, often new transformers. Most commercial sites are Level 2 sites; DCFC belongs on corridors and fleet depots.
Do I need a GFCI breaker for a hardwired charger?
Usually no — listed hardwired Level 2 EVSE contains its own charging-circuit interrupting device, and many manufacturers prohibit an upstream GFCI because the devices conflict. Receptacle-connected units are different: the receptacle GFCI rules apply. Follow the unit's manual; 110.3(B) makes it binding.
What does 'networked' add beyond a dumb charger?
Access control and payment, load sharing across a circuit, energy reporting, utility demand-response participation, and the EMS function that 625.42 sizing may depend on. If the load calc uses management, networking isn't optional — it's the compliance mechanism.
Can chargers go on the house meter of a multifamily building?
They can be supplied from any adequately sized service with the required calculation — house panel, dedicated meter, or tenant meters, each with different billing implications. Many utilities offer EV rates or make-ready programs that decide this; check the serving utility's programs before finalizing the one-line.
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