■ NFPA 70 National Electrical Code

Article 708 — the standby article with a risk assessment in it.

Most data centers are served by optional standby systems under Article 702. Some — those serving designated critical operations areas — fall under Article 708, which is materially more demanding and includes requirements that read more like an operations standard than a wiring code.

Scope

Article 708 applies to the installation, operation, monitoring, control and maintenance of the portions of the premises wiring system intended to supply, distribute and control electricity to designated critical operations areas (DCOAs) in the event of disruption to elements of the normal system. Critical operations power systems are generally installed in vital infrastructure facilities that, if destroyed or incapacitated, would disrupt national security, the economy, public health or safety.

§ Does it apply to your facility?

Get the designation in writing early

Whether Article 708 applies is a design-phase question with large cost consequences — fire protection of feeders, physical security, redundancy, monitoring and commissioning. Discovering it at the end is expensive.

§ What Article 708 adds

01

Risk assessment. The Code requires one, addressing hazards that could cause disruption — natural and human-caused — and the identification of mitigation strategies. This is unusual for the NEC and reads much more like a facility resilience requirement.

02

Physical security. Access control and protection of the COPS distribution equipment.

03

Fire protection. Feeder circuit protection requirements — fire-rated assemblies, encasement, or protected routing.

04

Testing and maintenance. Written record of testing, and maintenance performed in accordance with manufacturer instructions and industry standards.

05

Commissioning. The system must be commissioned, with documentation.

06

Monitoring. Continuous monitoring of the COPS with annunciation.

07

Selective coordination. Overcurrent devices serving a COPS must be selectively coordinated with all supply-side devices.

What this means in a data center

The selective coordination requirement is the one with a direct 70E consequence. Full selective coordination means upstream devices must be delayed relative to downstream ones — and delay is incident energy. A perfectly coordinated system can have very high arc flash values at the upstream gear.

This is the clearest example of a code requirement that raises the field hazard for a legitimate reason. The mitigation is arc energy reduction under 240.67 and 240.87 — a maintenance switch or zone-selective interlocking that lets a technician temporarily trade coordination for speed while they are standing in front of the gear.

If your facility is selectively coordinated and has no arc energy reduction method, that is the conversation to have with engineering.

§ The four standby articles

ArticleSystem typeTriggerData center relevance
700Emergency systemsLegally required by municipal, state, federal or other code, for illumination and power essential for life safetyEgress lighting, fire alarm, smoke control
701Legally required standbyRequired by a governmental agency; serves loads whose failure could create hazards or hamper rescueSometimes fire pumps, smoke removal
702Optional standbyElective — protects business, process, dataMost commercial data center generation
708Critical operations powerDesignated critical operations areaFacilities designated as vital infrastructure
Coordination raises incident energy

Train people to read the label and the study

The 16-hour class covers incident energy methods, coordination trade-offs and arc energy reduction.

See the 16-hour class Bring it onsite