The recommended wire size for a 48 Amp EV charger is 4 AWG copper or 3 AWG aluminum. This is necessary because a 60 Amp dedicated circuit breaker is required for the installation, and the National Electrical Code (NEC) mandates that electrical circuits be rated for at least 25% more amperage than the output.
The correct wire size for a 48A EV charger on a 60A circuit breaker is 4 AWG copper or 3 AWG aluminum per the NEC. However, factors like distance from the panel, voltage drop, insulation type, temperature, and conductor type may affect the final wire size.
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Best 48-Amp EV Charger
We recently installed and tested 48-amp level 2 chargers also known as 11.5 kW EV chargers on a three-phase EV charger installation, this type of installation is common in both residential and commercial EV charger installations and requires a 208V electrical power supply or 240V electrical power supply to the electrical panel.
48 Amp EV charger we installed and recommend includes the Emporia Level 2 EV Charger, Grizzl-E 48A Ultimate Level 2 Fast Electric Vehicle (EV) Charger, and Tesla Universal Wall Connector among others learn more >>
These 48 Amp EV chargers are heavy-duty high-power devices whose electrical branch circuit wiring requires careful planning to ensure the correct wire size is used which is crucial for both EV charging safety and efficiency.
Factors to Consider When Selecting 48 Amp EV Charger Wire Size
When selecting a 48 Amp EV charger or 11.5 kW EV charger wire size for your hardwired EV charger installation or plug-in EV charger installation (plug-in 48 Amp EV chargers are not common). you must consider several factors.
- EV charger installation voltage drop: Depending on the point of use, you might require a long wire run from the electrical panel to the EV charger which increases the chances of voltage drop in an electric vehicle (EV) charger, for point of use which exceed 50 feet we recommend increasing the electric vehicle branch circuit wire size to prevent voltage loss that occurs through a circuit due to impedance.
- Temperature rating: We recommend installing a 48 Amp EV charger or 11.5 kW EV charger with 4 AWG copper wires rated 60°C (140°F) or 75°C (167°F) to protect your EV charger installation against temperature changes when charging your electric vehicle.
- Wire Insulation: 48 Amp EV charger or 11.5 kW EV charger requires 4 AWG copper insulated with THHN (Thermoplastic High Heat-resistant Nylon-coated) or THWN (Thermoplastic Heat and Water-resistant Nylon-coated) to protect your EV charger installation from moisture, temperature changes and physical damage.
What Is the Right Size Wire for a 48-Amp EV Charger?
According to NEC Table 310.15(B)(16) (formerly Table 310.16) table, the recommended wire size for a 48 Amp EV charger which requires a 60 Amps dedicated circuit breaker is 4 AWG copper or #3 AWG aluminum, keep in mind the factors we have mention above such as voltage drops, temperature ratings and wire insulation might influence the wire size for your EV charger installation.
Based on the NEC Table 310.15(B)(16) (formerly Table 310.16) table you can use a 4 AWG copper or 3 AWG aluminum wire to install a 48 Amp EV charger with a 60 amps dedicated circuit breaker in your electrical panel, however, we recommend copper wires instead of aluminum as aluminum has high electrical resistance and lower conductivity than copper which might affect your EV charging efficiency.
48 Amp EV Charger Wiring – NEC – US
Depending on your EV charger wiring requirements, you might need a 4-4 with ground wiring, or 4-3 with ground wiring.
We recommend hardwiring a 48-Amp EV charger instead of using a NEMA plug-in installation.
4-4 With Ground Wiring for a 48-Amp EV Charger – NEC – US
4-4 with ground wiring for a 48-Amp EV charger installation requires four conductors of 4 AWG wires (typically two hots, one neutral, and one additional wire, often for a specific need such as a second neutral or hot) connecting the 48-Amp EV charger and its 60 amps three poles dedicated circuit breaker in a three-phase 240V electrical panel, and a ground wire connecting the charger to the ground busbar of your 240V three phase electrical panel as shown in the 4-4 with ground Wiring for a 48-Amp EV Charger wiring diagram below:
In our 4-4 With Ground Wiring installation for a 48-Amp EV Charger, we used the Siemens Q360 60-Amp Three-Pole Type QP Circuit Breaker.
4-3 With Ground Wiring for a 48-Amp EV Charger – NEC – US
4-3 with ground wiring for a 48-Amp EV charger installation requires three conductors (two hots and one neutral) connecting the 48-Amp EV charger with its 60amps double pole dedicated circuit breaker in a three-phase 240V electrical panel, and a ground wire connecting the charger to the 240V three phase electrical panel ground busbar as shown in the 4-3 with ground wiring for a 48-Amp EV charger wiring diagram below:
In our 4-3 With Ground Wiring installation for a 48-Amp EV Charger, we used the Siemens Q260 60-Amp Double Pole Type QP Circuit Breaker.
48 Amp EV Charger Circuit Breaker Size – NEC – US
The dedicated circuit breaker size for a 48 amp EV charger is typically 60 amps, this is according to the NEC 125% rule which states that the rating of an overcurrent device (breaker or fuse) should be at least 125% of the continuous load circuit (loads operating for more than 3 hours which a 48 amp EV charger falls into)
The breaker size for a 48 amp EV charger is calculated as follows according to the NEC 125% rule:
48Amps * 125% = 60Amps
Now based on the NEC Table 310.15(B)(16) (formerly Table 310.16) table a 4 AWG copper or #3 AWG aluminum is suitable for installation of a 48 amp EV charger that requires a 60amps dedicated circuit breaker.
We recommend connecting only the 48 amp EV charger to a dedicated 60 amp circuit breaker using 4 AWG copper or #3 AWG aluminum as per the NEC 125% rule, allowing the charger to draw a maximum of 48 amps, installing any other appliance to the circuit will lead to the circuit overheating which can cause injury or fire hazard when charging your electric vehicle with the 48 amp EV charger, this is because the devices will draw more than 48 amps.
Tip
For safe and efficient 48-amp EV charger installation, consult a licensed electrician or certified EV charger installer to verify the appropriate wire size and ensure compliance with NEC standards. They will also account for factors such as voltage drop, conductor type, insulation, and installation conditions to guarantee optimal performance and safety.
Last update on 2024-12-15 / Affiliate links / Images from Amazon Product Advertising API
