EV Charging Station: Level 2 and Level 3 Equipment, Construction, and Maintenance

Explore EV charging station equipment, construction, maintenance.

EV Chargers for Public Charging

Building a public EV charging station, with multiple EV chargers, is a relatively complex project. As the transition to electric vehicles (EVs) accelerates, the demand for efficient and accessible charging infrastructure has become critical. To accommodate the growing number of EV’s on the road, charging stations need to provide reliable, fast, and safe power delivery.

U.S. Department of Energy Information

The U.S. Department of Energy website is a great source to get more information for planning, designing, and building commercial or industrial EV charging stations. The article expresses the necessity to hire only companies with substantial experience building commercial EV charging facilities. The article specifically states, "Installing charging infrastructure can involve complex payment structures, data collection, ownership models, parking, and signage requirements, in addition to typical infrastructure considerations like cost, regulations, safety, efficiency, and type of equipment."1

Types of Commercial Electric Vehicle Chargers

The two most common types of charging stations are Level-2 and Level-3, also known as DC Fast Charging stations. Both levels of charging offer distinct advantages in terms of speed and application, and understanding the equipment, construction, and maintenance of these stations is crucial for building a sustainable EV infrastructure.

The Best EV Charger Brands

To get an optimal ROI, you should buy and install only the best brands of EV chargers. By installing the quality equipment you are ensuring minimal downtime, optimal performance, and a superior life-cycle cost. The Metoree website offers information on the best EV chargers for commercial charging stations. The website describes the page as, "This section provides an overview for electric vehicle chargers as well as their applications and principles. Also, please take a look at the list of 39 electric vehicle charger manufacturers and their company rankings."2 AC & DC Power Technologies offers expert consulting and can procure and install almost any brand of EV charging equipment.

This article explores the key elements of Level 2 and Level 3 EV charging station equipment, the construction processes required for their installation, and the best practices for maintaining these systems.

1. Overview of Level 2 and Level 3 Charging Stations

Level 2 Charging Stations

Level 2 EV chargers typically deliver power at 240 volts AC (alternating current), which provides faster charging than standard residential outlets (Level 1 charging, which uses 120 volts). Level 2 chargers are common at homes, workplaces, public parking lots, and retail locations. These stations are ideal for EV owners who need to charge their vehicles over several hours, typically during work or overnight at home.

Key characteristics of Level 2 chargers:

  • Voltage: 208-240V AC
  • Power output: 3.3 to 19.2 kW
  • Charging time: Adds about 10-60 miles of range per hour of charging, depending on the vehicle and charger power level
  • Use cases: Home charging, workplace charging, public destination charging

Level 3 Charging Stations (DC Fast Charging)

Level 3 chargers, commonly known as DC Fast Chargers (DCFC), deliver power directly to the vehicle’s battery at a much higher voltage. These chargers convert AC power to DC (direct current) before delivering it to the vehicle, significantly reducing the charging time. Level 3 stations are generally located at highway rest stops, service stations, and other areas where drivers need to quickly recharge on long journeys.

Key characteristics of Level 3 chargers:

  • Voltage: 400-900V DC
  • Power output: 50 kW to 350 kW or higher
  • Charging time: Adds 100-200 miles of range in about 30 minutes (depending on the charger and the vehicle)
  • Use cases: Long-distance travel, commercial fleets, public fast-charging hubs

2. Equipment for Level 2 and Level 3 Charging Stations

The equipment used in Level 2 and Level 3 charging stations is designed to meet different needs in terms of power delivery, charging speed, and user interaction. Below is an overview of the main components of each type.
2.1. Level 2 Charging Station Equipment

A typical Level 2 charging station includes the following key components:

  • Charging Unit (Electric Vehicle Supply Equipment – EVSE): The main unit that regulates the flow of electricity and communicates with the EV. It ensures safe power delivery and monitors charging status.
  • Charging Cable and Connector: Level 2 chargers in North America typically use a J1772 connector, which is compatible with most EVs. Tesla vehicles require an adapter to use these chargers.
  • Power Supply and Breaker Panel: Level 2 chargers need a dedicated 240V power supply. The station is connected to the building’s electrical panel through a circuit breaker, ensuring safe and controlled power distribution.
  • User Interface: Many Level 2 chargers include a display or mobile app integration that shows charging status, power delivered, and time remaining. Advanced units may also support payment processing for public use.
  • Mounting Hardware: Level 2 chargers can be wall-mounted or installed on pedestals. Commercial installations may use weatherproof enclosures to protect the equipment from the elements.
2.2. Level 3 Charging Station Equipment

Level 3 charging stations require more complex and powerful equipment due to the higher power levels involved:

  • DC Power Conversion Unit: Unlike Level 2 stations that provide AC power, Level 3 chargers include an integrated AC-to-DC converter, which allows the station to supply high-voltage DC power directly to the EV’s battery.
  • High-Power Charging Cables and Connectors: The cables in Level 3 chargers are thicker and more robust to handle higher currents. Connectors include CCS (Combined Charging System), CHAdeMO, and Tesla’s proprietary Supercharger plug. The connector type varies depending on the vehicle and region.
  • Cooling System: Due to the high power levels, Level 3 charging cables and internal components often require active cooling systems, such as liquid-cooled cables, to prevent overheating. Transformers and Electrical Infrastructure: Level 3 chargers typically require dedicated transformers and substantial electrical infrastructure upgrades, as they pull significantly more power from the grid.
  • User Interface and Payment Systems: Like Level 2 stations, Level 3 chargers often include user-friendly interfaces with screens or mobile app integration for monitoring the charging session. Public Level 3 chargers also feature payment systems to facilitate transactions.
  • Safety and Communication Modules: High-speed chargers include advanced safety features such as ground fault detection, overcurrent protection, and communication protocols to ensure safe and efficient energy transfer.

3. Construction and Installation of Charging Stations

The installation process for Level 2 and Level 3 charging stations varies significantly due to differences in power requirements and infrastructure needs.

3.1. Level 2 Charging Station Installation

Level-2 EV charging station installation is relatively straightforward, especially for residential or small commercial applications. The main construction elements include:

  • Site Assessment: Before installation, a site assessment is conducted to determine the best location for the charger, ensuring easy access to the power supply and vehicle parking. The site should be weather-protected and safe from potential hazards.
  • Electrical Work: A certified electrician will run a dedicated 240V line from the electrical panel to the charging station. This often requires installing a new breaker or upgrading the existing panel to handle the additional load.
  • Mounting and Hardware Setup: The charging unit is mounted on the wall or pedestal, and the electrical connections are made. Some installations may require trenching or minor construction work to route power to an outdoor location.
  • Testing and Commissioning: Once installed, the system is tested to ensure it functions properly and safely. This includes verifying power delivery, charging speed, and communication with the EV.
3.2. Level 3 Charging Station Installation

Level-3 EV charging station installation is a more complex process due to the higher power levels and infrastructure requirements. Key steps include:

  • Site Planning and Permitting: Installing a Level 3 charger often involves significant planning, including securing permits from local authorities and utility companies. The site must have adequate space for vehicles and charging equipment, and the electrical grid must be able to support the high power demand.
  • Electrical Upgrades: Level 3 stations may require extensive electrical upgrades, including the installation of new transformers, switchgear, and circuit breakers. This can involve trenching and laying new electrical lines from the nearest power substation.
  • Construction and Mounting: In addition to electrical work, civil engineering may be required to install concrete pads, bollards for vehicle protection, and enclosures for transformers and other equipment.
  • Cooling and Ventilation Systems: Due to the high power output, some Level 3 chargers need specialized cooling systems. These systems must be installed and tested to ensure the station can handle sustained charging without overheating.
  • Testing and Safety Checks: Like Level 2 chargers, Level 3 installations require comprehensive testing. This includes not only electrical and performance testing but also verifying the cooling systems and safety features.

4. Maintenance of Level 2 and Level 3 Charging Stations

Regular maintenance is essential for ensuring the long-term reliability and safety of both Level 2 and Level 3 EV charging station equipment. Preventive maintenance helps prevent breakdowns, minimizes downtime, and ensures the charging station delivers optimal performance.

4.1. Level 2 Charging Station Maintenance

Level 2 stations have relatively simple maintenance requirements, but regular checks are still necessary:

  • Visual Inspections: Periodic visual inspections can help identify potential issues, such as wear on cables, connectors, or mounting hardware. Check for damage caused by environmental factors or vehicle collisions.
  • Electrical Testing: Ensure that the power supply remains consistent and that safety features like ground fault detection are functioning properly. Annual testing of the charging equipment is recommended.
  • Software Updates: Many Level 2 chargers are connected to the internet or a cloud management system. Keeping the firmware and software up to date ensures optimal performance and security. Cable and Connector Care: Regular cleaning and inspection of charging cables and connectors prevent corrosion and wear, especially in outdoor environments.
4.2. Level 3 Charging Station Maintenance

Due to the complexity of Level 3 chargers, maintenance is more involved:

  • Cooling System Maintenance: For chargers with liquid-cooled cables or other cooling mechanisms, the system should be regularly inspected and serviced to ensure proper operation.
  • Electrical and Transformer Inspections: Since Level 3 stations draw significant power, regular inspection of transformers, switchgear, and power distribution systems is critical. Over time, components can degrade, leading to inefficiencies or failures.
  • Safety and Communication Systems: Testing and updating the safety systems, including overcurrent protection and ground fault detection, is crucial. Additionally, ensure that communication protocols between the station and vehicles remain up-to-date.
  • Firmware and Software Management: Level 3 stations.

If you need EV charging station new construction, EV chargers, power equipment or maintenance, call AC & DC power Technologies at 404-361-3788.


CREDITS and FOOTNOTES

  • 1 Staff Writers, "Procurement and Installation for Electric Vehicle Charging Infrastructure", February 14, 2022, Available from U.S. Dept of Energy
  • 2 Staff Writer, "39 Electric Vehicle Charger Manufacturers in 2024", November 15, 2023, Available from Meteoree
  • Photo by Paul Brennan, available at Pixabay

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