Part 5: Equipment Selection
Selecting the right EV charging equipment is essential to providing a seamless customer experience while aligning with your business goals. This blog reviews key factors to consider, such as charger capacity, charging speed, and power requirements, to help you make better informed decisions for your EV charging sites.
The first step in choosing a Level 3 DC fast charger is to determine what kind of end-user experience you want to provide for your customers. This will depend on your business model, your target market, and your site location.
For example, if you are operating a highway rest stop, you may want to keep your customers on the site for an extended period of time, so they can use your other on-site services, such as food, restrooms, or shopping. In this case, you may opt for a lower-power Level 3 DC fast charger, such as a 50 kW or a 100 kW charger, which will take longer to charge an EV, but will also be cheaper to install and operate.
On the other hand, if you are operating an urban center, you may want to attract more customers by offering a fast and convenient charging service, so they can quickly resume their journey or their activities. In this case, you may opt for a higher-power Level 3 DC fast charger, such as a 150 kW or a 350 kW charger, which will charge an EV in a matter of minutes, but will also be more expensive to install and operate.
Of course, these are not the only scenarios, and you may have a different end-user experience in mind. The key is to align your charger selection with your business goals and your customer needs.
EVALUATE YOUR CHARGER CAPACITY & PRICING STRATEGY
In choosing a Level 3 DC fast charger you need to evaluate the capacity of your charger, which is the maximum power output that your charger can deliver. The capacity of your charger will affect the charging speed, the charging cost, and the electrical infrastructure requirements of your site.
CHARGING SPEED
The charging speed is the time it takes to charge an EV battery from a certain state of charge (SOC) to another. For example, a 50 kW charger can charge a 60 kWh battery from 0% to 80% SOC in about an hour, while a 350 kW charger can do the same in about 10 minutes. The charging speed will influence the customer satisfaction and the throughput of your site.
CHARGING COST
The charging cost is the amount of money that you need to pay for the electricity that your chargers consume. Analyze the electricity pricing structure in the region where the charging station is located. Different locations may have varying electricity rates and time-of-use demand chargers. Consider a charger that can facilitate dynamic pricing based on factors like time of day, demand, and availability of charging stations.
To evaluate the capacity of your charger, you need to balance the trade-offs between the charging speed, the charging cost, and the electrical infrastructure requirements, and select a charger that meets your expectations and your budget.
DETERMINING THE RIGHT SWITCHGEAR
You can generally look to a few electrical specifications of the selected chargers to appropriately size the required switchgear. A good place to start is to figure out the required circuit breaker sizes to be included in the switchgear. You will need to figure out what you need for both the individual branch circuit breakers for each charger and the main circuit breaker. Here’s how to do it based on the diagram to the right:
You can generally look to a few electrical specifications of the selected chargers to appropriately size the required switchgear. A good place to start is to figure out the required circuit breaker sizes to be included in the switchgear. You will need to figure out what you need for both the individual branch circuit breakers for each charger and the main circuit breaker. Here’s how to do it based on the diagram to the right:
STEP 1: CHARGER INPUT CURRENT
Find the charger datasheet and locate the Input Current. The input current of a DC fast charger is the maximum amount of electric current that the charger can draw from the power source. In this example, our 200 kW chargers each have a rated input current of 300 Amps.
STEP 2: BRANCH BREAKER SIZES
To find the branch breaker size each charger will require, we need to apply the 80% rule as circuit breakers should not be loaded to more than 80% of their rated capacity for continuous loads. Use this formula:
As branch circuit breakers are generally sized to the nearest 100 Amps, a 400 Amp branch circuit breaker will be required for each charger.
STEP 3: MAIN BREAKER SIZE
To find the main breaker size required, we need to add up the total rated current for all chargers as the main breaker will handle protection for all chargers and then also apply the 80% rule. Use this formula:
As main breakers are sized to 1,000, 1,200, 1,600, 2,000 and 2,500 standard sizes, a 1,600 Amp main circuit breaker will be required for this site.
Preparing for the Power Requirements
If you are planning to install a Level 3 DC fast charger for your EV charging site, you will likely need a 480V distribution transformer to supply the high voltage and current required by the chargers. However, not every EV charging site can easily access a 480V distribution transformer, as it depends on the availability and capacity of the local electrical grid. Therefore, it is important to work with your local utility as early in the process as possible to ensure the proper 480V distribution transformer is selected for your EV charging site. Here’s a checklist of important information you should have ready when contacting the local utility provider:
Location Information
The first step is to contact your local utility well in advance, preferably before you finalize the location and design of your EV charging site. Your local utility can help you assess the feasibility and cost of installing a 480V distribution transformer at your desired location, based on the following factors:
- The distance and route from the nearest 480V transmission line to your EV charging site.
- The existing and projected load and demand of the local electrical system.
- The potential impact and benefits of your EV charging site on the local electrical system.
- The environmental and regulatory requirements and standards for installing a 480V distribution transformer.
Charger Information
The second step is to provide your local utility with the necessary information and specifications of your EV charging site, such as:
- The type and number of Level 3 DC fast chargers you plan to install
- The expected power and energy consumption of your EV charging site
- The expected usage and operation patterns of your EV customers
- The desired performance and reliability of your EV charging system
HOW CAN NEXPHASE™ HELP?
The NexPhase™ Smart EV Switchgear is an all-in-one panel containing the entire infrastructure required between the utility service and up to four Level 3 DC fast chargers totaling 800 kW. Unlike any switchgear of its kind, the NexPhase™ features cutting-edge grid intelligence for complete EV charging station remote uptime monitoring and control.
UPTIME ASSURANCE
Provides ongoing EV charger state-of-charge and utility power monitoring, enabling CPOs to accurately pinpoint charger outages, even when charger communications are down. The remote power cycle capability helps bring chargers back online faster.
TRUCK ROLL MITIGATION
The embedded monitoring system provides remote access to real-time switchgear, utility power, and charger health data with automated alarms for condition-based maintenance planning.
DESIGN SIMPLIFIED
Eliminates the lengthy design process of traditional post-and-frame systems, which require additional costs to design, permit, and source a mixed-manufacturer panel system. NexPhase™ eliminates sourcing and supply chain delays as a single-manufacturer, turnkey solution.
INSTALLATION MADE EASY
Requires minimal on-site connections for the incoming power and outgoing charger connections, drastically reducing on-site installation time and electrician costs.
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