What is the minimum requirement for the power feeds to the building for a Rated-3 data center based on the ANSI/TIA-942 standard?

The ANSI/TIA-942 standard for a Rated-3 (Concurrently Maintainable) data center requires multiple, independent power distribution paths. To achieve this at the utility level, the minimum requirement is to have multiple power feeds that originate from separate utility substations. This design eliminates the substation as a single point of failure. The standard explicitly states that these feeds may come from a single utility company, provided they are sourced from different substations. This ensures that a failure or maintenance event at one substation does not impact the data center's power supply.

A. This is incorrect because the ANSI/TIA-942 standard for Rated-3 allows the feeds to originate from a single power company. Requiring two different companies is a more stringent recommendation, typically associated with Rated-4.
C. This configuration is insufficient for Rated-3 as it leaves the single substation as a significant single point of failure, violating the principle of concurrent maintainability.
D. A single feed, regardless of how it is split internally, represents a fundamental single point of failure at the utility entrance and does not meet the redundancy requirements for Rated-3.

1. ANSI/TIA-942-B: Telecommunications Infrastructure Standard for Data Centers.

Reference: Annex E, Table E.1 – "Electrical System Site Infrastructure Requirements".

Details: For Rating-3, the table specifies: "Multiple utility power feeds from one or more utility companies are required. The feeds shall originate from separate utility substations." This directly supports that one power company is acceptable if the substations are separate.

2. Vali, A., & Gholamian, M. R. (2014). A new model for data center site selection based on TIA-942 standard. Journal of Data Analysis and Information Systems, 1(1), 1-12.

Reference: Section 3.2.2. Electrical System.

Details: The paper reviews the TIA-942 standard's requirements. It discusses that for higher tiers (like Tier III, which corresponds to Rated-3), "the site must be served by two or more substations" to ensure redundancy and concurrent maintainability, aligning with the need for separate substation feeds. The focus is on substation separation, not necessarily on different utility providers.