Electric vehicle charging infrastructure is one of the fastest-growing segments in electrical construction. Every charging station — from a single Level 2 unit at a retail location to a 50-stall DC fast charging plaza or a fleet depot with hundreds of connections — requires properly sized and rated wire and cable for the service entrance, distribution panels, branch circuits to each charger, and the communications network that manages them.
Ramcorp Wire & Cable supplies the cable products used in EV charging installations — from medium-voltage cable for service extensions and customer-owned power infrastructure through building wire for main feeders and branch circuits to each EVSE unit, underground distribution cable for parking lot conduit runs, and network cable for OCPP and smart charging communications.
Cable Types Used in EV Charging Infrastructure
EV charging installations require cable for utility service, power distribution, branch circuits to each charger, underground conduit runs, and communications networks. The table below covers the primary cable types, their function, and where they are installed in EV charging projects.
| Cable Type | Function | Common Specs | Where It's Installed |
|---|---|---|---|
| Building Wire (THHN / THWN-2 / XHHW-2) | Main feeders, sub-feeders, branch circuits to each EVSE unit | 14 AWG – 500 kcmil, 600V, 90°C, copper or aluminum | Service entrance to main panel, distribution panels, branch circuits to each charging station |
| Medium-Voltage Cable (MV-105) | Service extensions and customer-owned infrastructure for high-capacity charging sites, depending on utility requirements | 5 kV – 35 kV, 1/0 AWG – 500 kcmil, copper or aluminum | Customer-owned service extensions, pad-mount transformer feeds, duct banks for large charging plazas and fleet depots |
| Underground Distribution Cable | Underground branch circuits and feeders across parking lots and charging plazas | Typically installed in conduit using THWN-2 or XHHW-2 conductors; direct burial (UF-B, USE-2) used only where permitted and less common in paved commercial sites | Underground conduit from distribution panel to each charger pedestal, parking lot trenching |
| Tray Cable (TC-ER) | Power and control where cable tray systems are implemented | 14 AWG – 2/0 AWG, 600V, sunlight resistant | Used where cable tray systems are implemented, particularly in fleet depots and structured parking environments |
| Network Cable (Cat6 / Cat6A) & Fiber Optic | OCPP communications, smart charging management, payment systems, load balancing | Cat6/Cat6A for local runs; fiber optic for backbone and long-distance communications; outdoor-rated, shielded where required | Between chargers and network switch/gateway, to cellular modem or site controller, backbone between buildings |
| Tracer Wire | Underground utility locating for non-metallic conduit | 12–14 AWG, solid copper, HDPE jacket | Alongside PVC conduit runs in parking lots and driveways per municipal codes |
| Portable Cord (SOOW) | Temporary power and construction-phase use; limited use in permanent EV infrastructure | 12 AWG – 2/0 AWG, 600V, flexible rubber jacket | Construction temporary power, portable generators during build-out |
Cable by Charging Application
Cable requirements vary significantly depending on the scale and type of EV charging installation. The table below maps common cable types to each application and the key electrical considerations.
| Application | Typical Setup | Primary Cable Types | Key Considerations |
|---|---|---|---|
| Level 2 — Commercial / Retail | 2–20 stations at retail, hospitality, workplace, or multifamily sites | Building wire (branch circuits), underground cable (parking lot runs), network cable | 40A–80A per station, 208/240V, panel capacity planning for future expansion, NEC 625 continuous load calculations |
| DC Fast Charging (DCFC) Plazas | 4–50+ high-power DC chargers, typically 150–350 kW (with many installations currently in the 120–180 kW range depending on equipment) | MV cable (where customer-owned), building wire (large feeders), underground cable, network cable | High power demand (often 2–10+ MW total site load), utility service upgrade required, MV transformer, NEC 625 sizing, NEVI compliance |
| Fleet Depots | 20–500+ chargers for transit buses, delivery trucks, school buses, corporate fleets | MV cable, building wire, tray cable, underground cable, network cable | Massive aggregate load (often 5–50+ MW), phased buildout, load management systems, overnight charging schedules, depot power infrastructure |
| Multifamily / Parking Structures | Shared charging in apartment complexes, condos, parking garages | Building wire, tray cable (in structures), network cable | Panel capacity in existing buildings, load sharing/management, metering per unit, NEC 625 and local EV-ready building codes |
| Highway Corridor (NEVI) | NEVI-funded stations every 50 miles along designated highway corridors | MV cable, building wire, underground cable, network cable | NEVI technical requirements (minimum 150 kW per port, 4+ ports), Buy American / BABA compliance, utility coordination |
Key Considerations for EV Charging Cable
NEC Article 625 — Electric Vehicle Power Transfer System
All EV charging installations must comply with NEC Article 625, which governs wiring, conductor sizing, overcurrent protection, and equipment installation for EVSE. A critical requirement: EV charging loads are classified as continuous loads, meaning conductors and overcurrent protection must be sized at 125% of the maximum circuit current. A 48A Level 2 charger requires a 60A circuit with conductors sized accordingly. For large installations with many chargers, NEC 625.42 permits load management systems that can reduce the required conductor and panel capacity — but the system must be listed and approved by the AHJ.
Conductor Sizing & Voltage Drop
EV charging circuits often involve long conductor runs — from the distribution panel across a parking lot to charger pedestals that may be 200–500+ feet away. Voltage drop becomes a significant factor at these distances. NEC recommends limiting voltage drop to 3% on branch circuits and 5% overall. Long runs to high-amperage chargers frequently require upsizing conductors beyond the minimum ampacity requirement to stay within voltage drop limits. Our AWG Wire Gauge Guide covers sizing tables and voltage drop calculations.
Underground Conduit & Parking Lot Installation
Most commercial EV charging installations require underground conduit runs across parking lots from the electrical panel to each charger location. Cable is typically installed in conduit using THWN-2 or XHHW-2 conductors rated for wet locations. Direct burial cable (UF-B, USE-2) is used only where permitted and is less common in paved commercial sites. Conduit must be installed at minimum cover depths per NEC Table 300.5, and tracer wire is required alongside non-metallic conduit per most municipal codes. Planning conduit routes and spare conduit for future expansion during initial construction avoids expensive re-trenching later.
NEVI & Buy American Compliance
The National Electric Vehicle Infrastructure (NEVI) Formula Program and other federally funded EV charging programs require compliance with Buy American and Build America Buy America (BABA) provisions. Wire and cable are subject to these requirements. NEVI-funded stations must meet specific technical standards including minimum 150 kW per charging port, at least four CCS ports per station, and 97% uptime requirements. Ramcorp stocks Made in USA wire and cable from domestic manufacturers and provides country-of-origin documentation for NEVI and other federally funded projects.
Future-Proofing & Capacity Planning
EV charging demand is growing rapidly, and installations built today should plan for expansion. This means sizing service entrance equipment, transformers, and main feeders for the ultimate buildout — not just the initial phase. Installing spare conduit during initial trenching is significantly cheaper than re-trenching later. Many jurisdictions now require "EV-ready" provisions in new construction (conduit, panel space, or full circuits to future charging locations) per local building code amendments or state regulations.
Utility Service Upgrades
Large EV charging installations — particularly DCFC plazas and fleet depots — often require utility service upgrades including new transformers, MV switchgear, and dedicated feeders. A 10-stall DCFC plaza at 350 kW per charger represents a 3.5 MW load — equivalent to a small commercial building. Fleet depots with hundreds of chargers can exceed 50 MW. Utility coordination, service applications, and lead times for transformer delivery should begin early in the project timeline.
Related Guides & Resources
- MV-105 Medium Voltage Cable Overview (5 kV – 35 kV)
- THHN vs THWN Building Wire: Ratings & Applications
- AWG Wire Gauge Guide: Sizes, Ampacity & Selection
- Direct Burial Cable: Types, Depth Requirements & Selection
- Tray Cable Applications & Selection Guide
- Tracer Wire for Underground Utilities
- Made in USA Wire & Cable: Why It Matters for Export
- How to Choose the Right Cable for Your Project
Frequently Asked Questions
What wire is needed for EV charging stations?
EV charging stations require building wire (THHN/THWN-2/XHHW-2) for branch circuits from the distribution panel to each charger, sized for continuous load per NEC 625 (125% of maximum circuit current). Underground conduit runs across parking lots typically use wet-rated conductors (THWN-2 or XHHW-2) in conduit. Large DCFC plazas and fleet depots may require medium-voltage cable for customer-owned service extensions. Cat6/Cat6A and fiber optic cable connect chargers to the site management system.
What size wire do I need for a Level 2 EV charger?
A 48A Level 2 charger (the most common commercial unit) requires a 60A circuit per NEC continuous load rules (125% of 48A). At 240V single-phase, this typically requires 6 AWG copper conductors for shorter runs. Longer runs across parking lots may require upsizing to 4 AWG or larger to limit voltage drop to the NEC-recommended 3%. Always calculate voltage drop based on the actual circuit length before finalizing conductor size.
Does NEVI-funded EV charging require Buy American cable?
Yes. NEVI Formula Program and other federally funded EV infrastructure programs require Buy American / BABA-compliant materials, including wire and cable. Ramcorp stocks Made in USA cable from domestic manufacturers and provides country-of-origin documentation and mill certifications for NEVI and other federally funded projects.
What is NEC Article 625 and how does it affect EV charging wiring?
NEC Article 625 governs the installation of Electric Vehicle Power Transfer Systems (EVSE). Key requirements include treating EV charging as a continuous load (conductors and overcurrent protection sized at 125% of maximum current), specific grounding and bonding requirements, and provisions for load management systems that can reduce required circuit capacity when multiple chargers share a common feeder. All EV charging installations must comply with Article 625 in addition to standard NEC wiring requirements.
Does Ramcorp supply cable for EV charging projects?
Yes. Ramcorp Wire & Cable supplies building wire, medium-voltage cable, underground distribution cable, tray cable, network cable, fiber optic cable, and tracer wire for EV charging installations ranging from single Level 2 stations to large DCFC plazas and fleet depots. We stock Made in USA products for NEVI/BABA compliance and support volume orders for multi-site rollouts.
Need Cable for an EV Charging Project?
Whether you're installing a few Level 2 chargers at a commercial property, building a NEVI-funded highway charging plaza, or electrifying a transit fleet depot, our team can help with product selection, Buy American documentation, volume pricing, and delivery coordination. We respond to quote requests within one business day.
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Disclaimer: This guide is provided for informational purposes only and is not installation advice. Installing wire & cable can be dangerous and pose a risk of possible electric shock or other hazards. Specifications, availability, and pricing are subject to change without notice. Always verify product specifications with the manufacturer's current datasheet before ordering. Consult a licensed professional for installation advice.
The information on this page is provided for general reference only and may contain errors or omissions. NEC® is a registered trademark of the National Fire Protection Association (NFPA®). All other trademarks, product names, and brand names referenced on this page are the property of their respective owners. Ramcorp Wire & Cable is not affiliated with or endorsed by these organizations unless explicitly stated.