Lithium-Ion Battery Q&A Series: Data Center Code Compliance

Posted by Lee Kaiser on Feb 28, 2023 9:00:00 AM


Join ORR Protection experts Lee Kaiser and Aaron Wille as they discuss Lithium-Ion battery safety and fire suppression systems for battery energy storage systems, like those found in data centers.

In this part of the series, our experts will explore data center code compliance issues by answering the following questions:

  1. Does NFPA 855 apply to the data center environment?
  2. Which sections of NFPA 855 refer to data centers?
  3. How does UL9540A apply to data centers?
  4. What should an end-user look for in the UL9540A listing and large-scale fire test report?

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All right, so probably the first question is NFPA 855. It's the code that relates to battery energy storage systems or energy storage systems in general. And one of the questions is, does NFPA 855 apply to the data center environment?

That's been coming up a lot, right? I think it does, but you've got to get a little bit, you got to follow our logic to get there. It is being referenced by the newest building codes. It's just a lot of the installations in different jurisdictions, different states, or cities, those codes may not be referenced yet. But, as far as the industry standard goes, which is what I feel cases will get litigated against if there's a problem because a building didn't follow a code that's out there or an industry standard code like 855, that's where I think it comes in, and I would say it applies. The way 855 is written, even though the current version may not be referenced. I think that it's 2018 is the current version of 855.

Really soon, the 2022 version is going to be published. But the 2018 version, may not be in the code that's enforced in that area, but it should be followed. It’s got billed into there this situation where it's retroactive to changes in battery technology inside of buildings, which, you mentioned data centers. That's what we're seeing. It's either new data centers being built with lithium-ion as the battery technology for UPS systems, or its existing data centers where they're switching from older technologies like lead acid batteries to lithium-ion.

855 covers a lot of different types of energy storage environments. For the people that want to invest in reading NFPA 855, or at least a section that's related to data centers, what section of NFPA 855 should they go to that relates to the data center environment?

They should go to the non-dedicated building section requirements. You must know the general requirements about lithium-ion battery installations or, just any battery because it covers all battery types. But then as far as building fire protection requirements, it's separated into requirements that apply to dedicated buildings where it's just a building that has lithium-ion batteries in it, or non-dedicated buildings, meaning it's a building that has other functions and part of it has lithium-ion. The data center environment, assuming that the batteries are inside the building where we traditionally have a battery room supporting the UPS systems, then they would need to look at the non-dedicated sections of 855.

We've talked a little bit about NFPA 855 and let's talk a little bit now about UL and the UL standards. Can you talk about UL 9540A and how that applies to the data center environment and the difference between a UL listing and the large-scale fire test reports and how that's important when you're evaluating technologies that go into a data center?

There's a lot in that question that is often confused. It's really confusing to everybody right now unless you are a battery manufacturer and you're creating product to submit to UL and get this testing done. So, you said what about the UL 9540A listing? That's not quite right, but that's how people understand it. UL 9540A is the actual listing of the battery system, that people would be trying to achieve with their product. UL 9540A is a fire test procedure or fire test method that they must follow, a battery manufacturer has to follow a packager of battery systems has to follow, in order to get the UL 9540A listing. 9540A it's neat. You got to know this when you get into battery systems. It’s a progressive fire test.

On the theme of ion battery systems, cars, even your scooters that we see on the street, they're built up of multiple lithium-ion battery cells. That test starts with burning one cell and seeing what happens. They look at how long does it take to catch on fire, and how difficult is it to catch on fire? And by the way, they all eventually catch on fire. And then, how severe is it, at what temperatures does that happen and what kind of gases does it give off? And they can measure all this stuff because they're doing it in a lab underneath, I think a cone calorimeter is what they use with other instrumentation and they measure all that and then they build it up to the next level, which usually when, you know because we're talking energy or UPS systems, that's a module, right?

That’s a bunch of batteries strung together in kind of a unit, and they'll do a module level test and then from there and, as you expect more battery cells, do you think the fire's bigger or smaller? It's going to be bigger. Yep, there you go. The fire gets bigger and then you go to the rack level test and they set a module on fire and then they watch the fire grow through the rack and basically the way 9540A testing is done, you're allowed to stop testing when the battery fire stops propagating, meaning stops getting bigger and so you ought to be able to, when you've got a battery installation, get that 9540A test results for the battery systems being installed. And then you use that as data to start designing the fire protection system features and requirements. Your system may be 9540 listed, but there should be separate 9540A test results made available to the purchaser of the equipment and the purchaser of the equipment needs to make it available to the fire protection design professionals that are part of this, the project team.

As a follow up to that, I think that's an important comment that a lot of people think of UL listed. UL listed means that it's safe and we can put it in our building versus the UL report, which means there may be additional data they have to review when they're considering putting different technologies in the data center like lithium-ion battery. We’ve got a diverse audience, we've got end users, we've got contractors, we've got engineers and architects. What is the type of data points or what are the type of things that an architect or an end user may want to look for in the UL 9540A large scale fire test report to help them figure out how they're going to need to build or construct their data center?

First off, there's just got to be 9540A test results because frankly, our company is involved in some, not specifically data center project at this point, but other energy storage system projects, which in my opinion are no different. But we're involved in those projects where that data is hard to come by. They’re existing installations. Now, people are out there, fire marshals are out there enforcing the code and they're wanting all the activity to get 90 or 855 applied to the building done. And that goes back to where's that 9540A test result so that we can use that as design data. It may, in some cases that don't exist because these systems have been installed for a while. And, as we talk about data centers, some of them in lithium-ion batteries have been installed for years already.

Until the enforcement activity of UL in 9540A testing has started to happen in the manufacturing world. There's plenty of installations that just don't have that data and now that data's starting to be available for new systems going in. That’s important — just does it exist or not. But from there, an architect engineer would be looking at what level did the testing stop, where did propagation stop? You really need to be concerned with battery systems that drove to full scale testing because it probably means that the fires got big enough that the fire went from one rack to another rack. And then at some point, once that happens, then they need to go to like a full installation with multiple racks and see how many racks wind up getting involved before they can control the fire with sprinklers.

And those are the things that they need to be looking at and saying, well, should we even be using this product or not? Now, I have a strong opinion and I'm going to qualify this as an opinion and not fact because I know we're going to have a lot of battery manufacturers watching our answers to this, but I think that in practical application installation of battery racks next to each other in an energy storage system, UPS applications being no different, we're seeing from the fire incidents that there is some rack to rack propagation because in the test environment, they can't let all the heat and all the smoke toxic gases, flammable gases that are coming off these batteries, they can't let that just build up in the lab, they're going to kill somebody, right? So when you get into a real situation where you've got these batteries contained in a room or in an other enclosure, I think the incidents that are out there show that there is rack-to-rack propagation. And the reality is we've got to be designing for pretty severe incidents in our actual design so that we, we don't limit the impact from the fire. Like Aaron, you've been to plenty of data centers and other installations where there's been fires. When there's fire and electronics, is it a big fire usually?

It really depends on whether it's got a way to kill the electronics to the machine space or the space itself. If we've got the ability to kill that power, the fire's usually contained in a small environment.

And I think that's what we're used to in data center spaces. Other electronic spaces are small fires because the fire experience we have kind of shows that, but this is different. With lithium-ion battery fires, what we want to get across to everybody is not that we expect them to happen frequently, we just expect that when they happen it's going to be severe and it's much more severe than what we're used to.

Topics: Data Center, Lithium Ion Battery

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