“A Tier 3 data centre is a location with redundant and dual-powered servers, storage, network links and other IT components. It is one of the most commonly used data centre tiers, where IT components are powered with multiple, active and independent sources of power and cooling resources.

A Tier 3 data centre is also known as a Level 3 data centre.”

Data centre tier levels refer to a data centre's ability to maintain functionality during various kinds of failures, such as power outages. Higher tier levels indicate more sustainability for data centre operations and fault-tolerant systems that will allow for uninterrupted use during certain kinds of emergencies or crises.

As more advanced technology has led to a greater evaluation of fault tolerance for data systems and other business processes, the global IT community has defined data centre reliability by referring to up to four tiers for data centre operations. Groups such as the Uptime Institute, a global research organization, have defined these tiers and provided certifications for data centre systems.

In a Tier 1 data centre, system processes are carried out through a single path in a non-redundant system that does not offer fault tolerance. In a Tier 2 system, there may be some redundant features, for example, in climate and energy source support. Tier 3 systems will typically have more comprehensive protections for power outages and will have what’s called N+1 redundancy, which is a reliable backup power system.