UL 2755

Outline of Investigation for Modular Data Centers

1.1 This Outline of Investigation covers Modular Data Centers (MDC). The Modular Data Centers covered by these requirements are pre-fabricated units consisting of an outer enclosure housing ITE and various support equipment such as electrical service and distribution equipment, HVAC systems and the like. Some configurations may have the support equipment housed in a separate enclosure. A typical construction may use a standard ISO shipping container or other structure as the outer enclosure, racks or cabinets of ITE, NEC compliant service entrance equipment and power distribution components, power storage such as a UPS and an air or liquid cooling system.

1.2 These factory-built modules incorporate pre-installed materials and equipment which, after installation, may be concealed and may not be accessible for inspection at the final installation site.

1.3 The modular data centers covered by these requirements are intended for fixed installation either indoors or outdoors based on their construction and resistance to environmental conditions. MDCs intended for outdoor use shall be identified with a NEMA environmental class rating.

1.4 These requirements are intended to demonstrate compliance with the National Electrical Code (NEC), NFPA 70 and other national Codes such as Building, Fire, Plumbing, Mechanical, and the like. Where state or local codes differ from the national codes anticipated by these requirements, determining compliance with these codes is the responsibility of the local authority having jurisdiction.

1.5 When these requirements do not cover a specific technology or construction feature, the applicable requirements of the National Codes shall be used.

1.6 This Outline of Investigation assumes that the final installation of the MDC will be performed by qualified service personnel in accordance with the applicable installation instructions, installation practices and national installation codes. These MDCs are intended for installation subject to approval by the Authority Having Jurisdiction.


  • Edition Number: 1
  • Edition Date: 10/31/2011
  • Price Code: A
  • Type: outline
  • ANSI Approved:
  • DOD Approved: