Power outages can be devastating. For many facilities, an outage of even a minute can result in the loss of millions of dollars, or worse, put human lives at risk. In emergency and legally required applications, where an outage would pose a life safety risk, National Fire Protection Association standard 110 is the standard for emergency and standby power systems. It outlines requirements for the installation and performance of backup power systems. In this guide, we’ll explore what NFPA 110 is, and what you should consider when implementing and maintaining your facility’s emergency power system.

In order to understand system requirements under NFPA 110, it is essential to define terms. When dealing with fuel requirements under NFPA 110, we look to the “class” section.
Your EPSS Class is the duration (in hours) your system must be able to run at its full-rated output without refueling (4.2).
For example, Class 2 requires your generator run for 2 hours without adding fuel,
Class 48 requires 48 hours and so on. Although some AHJ’s define “Class X”
differently, it generally translates to 96 hours of rated output.

Higher Classes pose a challenge for system designers, especially designers of larger systems, as enough fuel must be stored on site to satisfy the generator’s fuel consumption for the duration as defined by your Class.
For example: you require 18,000 gallons of fuel to run your EPS for 96 hours because you have a Class X EPSS installation. According to the 133% rule, you need to store almost 24,000 gallons on site. You’ll need to carefully size your fuel tanks and perform regular fuel maintenance to ensure compliance (7.9). You should also consider fuel supplier delivery logistics.
If you’re in a rural area where it’s going to take time to get more fuel if you run out, you should consider oversizing your tank even further.
You should work closely with your generator manufacturer to create a fuel storage and maintenance plan that complies with this standard and all applicable codes, without being cost prohibitive.
At ACF Standby Systems, we work alongside our customers to help them meet NFPA 110 fuel requirements. We are Florida’s generator experts, and you can trust us to ensure that your gen set is compliant with state codes.