800 VDC arc flash risk assessed in new Schneider study
Author: Joe Peck
Global energy technology company Schneider Electric has published an analysis of arc flash risk in 800 VDC power architectures, examining how different system designs, capacitor placement, and fault-clearing behaviour affect the potential for electrical hazards.
The analysis uses deployment scenarios based on hyperscaler design patterns and compares two emerging 800 VDC architectures with different configurations.
It finds that, even under conservative assumptions where capacitors dominate fault behaviour, arc flash risk in 800 VDC systems can be managed and, in some cases, is comparable with typical AC systems.
The study also finds that advanced software and digital twins can provide more detailed modelling of arc flash risk than simplified calculation methods.
The research comes as 800 VDC architectures are being considered for higher-density AI data centre racks. NVIDIA and other technology companies, including Schneider Electric, are working on power infrastructure intended to support racks rated at 400 kW and above.
As power densities increase, 800 VDC distribution is being considered for supplying higher-power racks while limiting distribution losses. However, higher operating voltages also require greater understanding of fault behaviour, protection coordination, and safe working practices.
Manish Kumar, EVP Secure Power & Data Centers, Schneider Electric, says, “800 VDC power distribution represents a significant shift in data centre design, but it also introduces safety considerations that need to be studied extensively.
“Our work with some of the world’s leading hyperscalers provides engineers and safety professionals with one of the first practical frameworks for evaluating arc flash risks, providing a structured approach to understanding fault behaviour, establishing safe work practices, and designing effective protection schemes.
“Our goal is to help the industry move towards higher-voltage architectures with confidence and safety.”
Two 800 VDC architectures examined
The analysis assesses rack-level and facility-level 800 VDC architectures, representing two implementation approaches being considered for data centre power distribution.
It compares standards-based methods, transient simulation, and system-level modelling, finding that existing arc flash frameworks can be applied to 800 VDC systems when the architecture and time-dependent behaviour of faults are taken into account.
For rack-level 800 VDC architectures, a sidecar (also known as a power rack) case study used conservative methods and assumptions. The results showed incident energy below the referenced 1.2cal/cm² PPE threshold, even without protection devices.
The facility-level case study showed the potential for slightly higher incident energy than the rack-level design. This assessment also used a conservative architecture without overcurrent protection.
The analysis examined system topology and the effect of fault locations upstream and downstream of reverse-blocking diodes on back-feed, peak current, and arc flash outcomes.
When fault contribution is limited in time using standard protection devices, the study found that arc flash energy can be reduced to levels appropriate for the working environment and generally comparable with common AC architectures.
The research identifies several factors that influence arc flash risk in 800 VDC systems:
• Transient behaviour matters — Arc flash is driven by time-dependent fault currents, with capacitor discharge dominating the first milliseconds of an event.
• Simulation can improve accuracy — Transient simulation and power system analysis tools can provide a more detailed assessment than simplified DC arc flash calculations, which the study finds can overestimate risk in capacitor-dominated systems.
• System design affects risk — Capacitor placement, reverse-blocking devices, and millisecond-scale protection can influence arc flash outcomes.
Tanuj Khandelwal, CEO of ETAP, notes, “Industry standards remain essential for arc flash and electrical safety, but traditional methods can be overly conservative because they do not fully reflect how complex DC systems operate.
“To understand real risk, engineers must evaluate system topology, fault behaviour, protection coordination, converter response, switching logic, and active protection schemes.
“ETAP enables teams to model and validate 800V DC systems as they perform, helping move from conservative assumptions to more accurate, AI-augmented, physics-based safety and operational decisions.”
The study concludes that system architecture and protection strategies are significant factors in determining arc flash risk in 800 VDC systems. It finds that overall risk can remain low and, in some cases, comparable with typical AC distribution, including when standard time-based protection devices are used.
Schneider Electric says the work builds on its previous arc flash safety testing and forms part of its work on 800 VDC power architectures for higher-density rack systems. The company has also conducted testing of live-swap power capabilities in 800 VDC systems for maintenance applications.
The full findings have been published in the new whitepaper, titled DC Arc Flash Analysis: A Practical Study on 800 VDC in Data Centers.
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