What installers should know about NFPA 70 Section 702.4

We’ve recently gotten questions about NFPA 70 Section 702.4 of the National Electrical Code. It’s become an increasing conversation between installers and homeowners in certain jurisdictions. Interpretations of this section can vary, and honestly, be a bit confusing. As more states move toward enforcing Section 702.4, we thought it would be helpful to explain the ins and outs, including its benefits for installers. Being prepared will not only ensure a smooth project completion, it will help you navigate any unforeseen challenges that may arise on the subject.

What is NFPA 70 Section 702.4 and why is it important? 

Section 702.4(A)(2) of the National Electrical Code applies to optional standby systems that use automatic load connection. Energy storage systems must either be capable of supplying the full load or use an Energy Management System (EMS) to manage the connected load. For example, if a homeowner backs up their house with solar and energy storage or with a generator on an automatic transfer switch, those systems would be considered optional standby systems and fall under article 702.

Here’s what that means; under the code’s strictest interpretation, solar batteries and generators set up for whole-home backup should have the capacity to supply the entire home’s electrical load. For example, homes with a standard 200-amp service would require upwards of 48 kW battery power. If you’re thinking that doesn’t sound realistic, you’re not wrong. Looking at the numbers, Tesla Powerwall 2 has a continuous power output of 5 kW. In this example, you’d need to install 10 Tesla Powerwall 2 batteries to stay up to code. That would be very costly for the homeowner, and the space to install a system of this size would likely not be available. So, what’s the solution? An EMS.

How does an EMS help installers comply with 702.4?

Energy management systems are intelligent devices that help homeowners manage their electricity. An example of this is a smart panel that controls specific electrical circuits within the home. The Lumin Smart Panel can provide affordable whole-home backup without the need to spend tens of thousands of dollars on power sources like solar batteries. Here’s how.

The Lumin Smart Panel conveniently connects with a residence’s electrical panel to help homeowners manage their electricity when and how they choose to do so. And it’s designed with easy installation in mind with the ability to retrofit into any home setup, helping installers reduce project completion timelines and avoid additional costs. Homeowners can choose to sync their preferred appliances with the Lumin Smart Panel to enable circuit scheduling and prioritization during a power outage. This is where compliance with Section 702.4 comes in.

When a Lumin Smart Panel automatically detects the outage, it snaps into action. Appliances designated as high priority (by the homeowners) are instantly supplied with backup power, while lower priority devices are available on-demand. In the case of a solar battery, the stored power will decrease over time depending on the electrical consumption needs of the appliances currently connected to it. In response, Lumin intelligently sheds off devices as needed to conserve energy. This extends your power supply, while also protecting your battery from nuisance tripping.

Why should EMSs be part of a standard energy storage package?

Selling homeowners a Lumin Smart Panel along with a solar + storage system is not only a no-brainer, it’s also the responsible thing to do. Most homeowners purchase energy storage systems to make their houses more resilient. The Lumin Smart Panel offers them the very definition of resiliency with its ability to communicate with a home’s circuits locally. Most energy management systems rely on a stable broadband connection or even cellular data to function properly. As you can imagine, this isn’t always available during extreme weather conditions when the risk of an outage is present. The Lumin Smart Panel is different. Homeowners can continue managing their power supply regardless of broadband or cellular interruptions.

Helping homeowners understand how energy management systems can maximize their solar + storage investment can give you a great selling point at the kitchen table while also increasing customer satisfaction. That means positive reviews and even referrals! Better yet, the price is right. Contact a Lumin representative to learn more.