The Importance and Requirements of Electrical Generators in Data Centres

Maximizing Availability and Compliance with Uptime Institute and ANSI/TIA Ratings

Introduction

Electrical generators play a key role in DCs operational continuity, guaranteeing power supply in the event of grid failures. To maximise availability and comply with standards set by Uptime Institute and ANSI/TIA, it is essential to design and implement appropriate power generation solutions.

Importance of Generators in Data Centre Availability

Generators provide critical backup power during grid interruptions, minimising the risk of downtime that could result in financial losses and service disruptions. Their performance is directly linked to the reliability classification of the data centre, as determined by Uptime Institute and ANSI/TIA:

• Uptime Institute defines four certification levels (Tier I to IV) that establish the availability and redundancy requirements of the infrastructure.
• ANSI/TIA-942 sets data centre categories (Rated 1 to 4) with specific criteria for power supply and recovery capability in the event of failures.

Technical Requirements for Data Centre Generators

1. Capacity and Sizing

Generator sizing must ensure support for the total load of the data centre without interruptions. Factors to consider include:

• Total energy consumption of critical equipment.
• Conversion losses in UPS and other devices.
• Future growth of electrical load.

2. Redundancy and Configuration

Redundancy schemes ensure the uninterrupted operation of the data centre:

• N+1: One additional generator beyond what is required for operational load.
• 2N: Double capacity to cover 100% of the load in case of failure.
• 2N+1: A 2N system with an additional generator for enhanced security.

3. Autonomy Time

Generators must have sufficient fuel to operate for as long as necessary until grid power is restored or fuel is replenished. Standards generally recommend:

• Tier III and IV (Uptime Institute): A minimum of 12 hours of autonomy.
• Rated 3 and 4 (ANSI/TIA-942): Depending on application criticality, between 12 and 24 hours.

4. Response and Transfer Time

• Generators must activate within 60 seconds of a failure.
• The use of automatic transfer switch (ATS) systems and load banks is recommended to ensure a fast and reliable start-up.

5. Maintenance and Periodic Testing

To ensure operability, generators must undergo:

• Monthly load testing to verify performance.
• Preventive and corrective maintenance as per manufacturer recommendations.
• Fuel and filtration system inspection to prevent diesel contamination.

Conclusion

Electrical generators are fundamental to data centre availability, ensuring compliance with Uptime Institute and ANSI/TIA-942 standards. Proper design, efficient redundancy, and a rigorous maintenance plan are essential to minimising the risk of outages and guaranteeing the continuity of critical operations. Investing in a reliable backup infrastructure is a strategic decision that directly impacts the security and efficiency of modern data centres.