Fundamental Requirement
As defined by the Uptime Institute, a Tier II data center has redundant capacity components and a single, non-redundant distribution path serving the computer equipment.
Performance Confirmation Tests
- Redundant capacity components can be removed from service on a planned basis without causing any of the computer equipment to be shut down.
- Removing distribution paths from service for maintenance or other activity requires shutdown of computer equipment.
Operational Impacts
- The site is susceptible to disruption from both planned activities and unplanned events. Operational (human) errors of site infrastructure components may cause a data center disruption.
- An unplanned capacity component failure may impact the computer equipment. An unplanned outage or failure of any capacity system or distribution element will impact the computer equipment.
- The site infrastructure must be completely shut down on an annual basis to safely perform preventive maintenance and repair work. Urgent situations may require more frequent shutdowns. Failure to regularly perform maintenance significantly increases the risk of unplanned disruption as well as the severity of the consequential failure.
Manufacture’s Run Time Limitation
Engine generators that have a limit on consecutive hours of operation at “N” demand are appropriate for Tier I or II.
Regulatory Run Time Limitation
Engine-generator systems often have an annual regulatory limit on operating hours driven by emissions. These environmental limits do not impact the consecutive hours of operation constraint established in this section.