The importance of electrical safety in data centers has been reinforced by an incident at a Google data center in which three workers were injured. It’s a reminder that even the most professionally run data centers must stay vigilant about worker safety related to arc flash, a type of electrical explosion.

The incident happened at the Google data center in Council Bluffs, Iowa, which is one of the world’s largest data center campuses.  Council Bluffs fire officials told CBS News that an arc flash occurred when three workers were accessing an electrical cabinet. The workers were reportedly in stable condition at an area hospital.


“We are aware of an electrical incident that took place today at Google’s data center in Council Bluffs, Iowa, injuring three people onsite who are now being treated,” Google said in a media statement. “The health and safety of all workers is our absolute top priority, and we are working closely with partners and local authorities to thoroughly investigate the situation and provide assistance as needed.”

The Hazards of Arc Flash

An arc flash is an electrical explosion that generates intense heat that can reach 35,000 degrees F, which can damage and even melt electrical equipment. Arc flash incidents also represent a significant threat to worker safety. An arc flash can be a dramatic event in a data center, where the power infrastructure handles enormous amounts of electricity.

Arc flashes have led to expensive outages in data centers, most notably a 2009 incident at Fisher Plaza in Seattle, which knocked a major online payment gateway offline, slowing global e-commerce. The event was blamed on an insulation failure on a busway, and the building owner incurred $6.8 million in cash expenses related to the fire, including remediation and capital projects.

There were a series of arc flash incidents during the construction and testing of the NSA data center in Utah, according to media reports, which said the events caused significant equipment damage.


The larger danger with arc flash is worker safety. According to the American Society of Safety Engineers, more than 3,600 workers suffer disabling electrical contact injuries annually.

Reducing arc flash hazards has been a growing priority for data center power vendors and the National Fire Protection Association (NFPA), which in 2012 introduced regulations designed to limit the scenarios in which technicians are working with energized equipment.

A good resource is Arc Flash Mitigation in the Data Center from The Uptime Institute, which discusses arc flash and electrical safety issues, and provides an overview of the essential measures data centers must follow to meet OSHA and NFPA 70E requirements.

The data center industry has history of discussing arc flash and its hazards. Here are some links to our prior stories on arc flash and electrical safety in the data centers, which remain worthwhile reading.

  • Facebook: Open Sharing Was Key to Addressing Arc Flash Incidents: At the 2017 7×24 Exchange fall conference, executives from Meta and Schneider Electric gave an in-depth review of a series of arc flash events at Facebook’s data center in Sweden, and how the company’s post-event analysis and response headed off other potential incidents. “How we talk about failure is important,” said James Swensen, Senior Global Facilities Operations Manager at Facebook. “Both of our organizations were concerned about sharing this story. It’s uncomfortable. It’s not fun. But if you don’t go through that pain, you’re not going to get to the lessons learned.”
  • It’s Time to Upgrade Data Center Safety: In this 2018 Voices of the Industry column, data center industry veteran Phillip Sandino discusses data center technicians working on energized equipment.  “We’ve changed our engineering, building designs, construction processes, etc. Now it’s time to take a hard look at our operational procedures so we can take steps forward to be a safer industry. “
  • The Future of Innovation in Electrical Infrastructure: In this 2017 edition of the DCF Roundtable, Robert Woolley of RagingWire discussed how continued improvement in the design of electrical distribution equipment has included arc resistant features that can improve worker safety.
  •  Weak Commissioning Poses Risks to Reliability, Safety: Compass Datacenters CEO Chris Crosby was an early voice in elevating discussion of arc flash safety hazards. At the 2014 Data Center World conference, Crosby called on service providers to commit to Level 5 commissioning of new data centers, which involves integrated testing of all mission-critical systems.  “Some companies are saying ‘we’ve pre-designed the data center, and can add UPS capacity later,’” said Crosby. “If you haven’t tested it at full load, you’re kidding yourself.”