Backup power is a critical infrastructure to ensure business continuity in data centers. Diesel generator sets (gensets) must respond quickly and provide stable power when the main supply fails. This guide explores international standards, performance requirements, and practical diesel generator selection recommendations.
1. International Standards
1. Uptime Institute Tier Standards (Tier I–IV)
Data center infrastructure is classified by availability, stability, and redundancy.
Tier IV: highest availability, fully fault-tolerant; continues operating during multiple equipment or system failures.
2. ANSI/TIA-942 (Telecommunications Infrastructure Standard for Data Centers)
Defines Tier I–IV data center infrastructure requirements, covering power, cooling, and redundancy.
3. NFPA 110 (US National Fire Protection Association)
Backup power systems must start within 10 seconds and support full-load operation for at least 24 hours.
4. Key International Requirements
Redundancy: N+1 or 2N configurations depending on data center Tier.
Transfer time: Total switch to backup power ≤15 seconds; critical loads may require zero interruption via UPS.
2. Performance Requirements
1. Reliability
Start-up success rate ≥99%; annual downtime <0.5%
Support frequent testing (≥12 starts per year)
2. Response Time
Cold start ≤10s, hot start ≤5s
Total time from main power failure to full-load supply ≤15s
3. Load Capacity
Handle step load (100% sudden increase) with voltage/frequency variation ≤±5%
Long-term power ≥110–120% of total IT load to accommodate future expansion
4. Fuel and Endurance
Fuel tank capacity must allow 24+ hours full-load operation, with provisions for external refueling
Fuel must comply with local diesel standards (EU Stage V / EPA Tier 4)
5. Noise and Emissions
Noise level ≤85 dB(A) at 1 meter from the unit
Comply with local emission standards (EU Stage V, EPA Tier 4)
6. Intelligent Management
Remote monitoring (oil pressure, coolant temperature, battery status, etc.)
Self-diagnostics and alarm functions
3. Diesel Generator Set Selection
1. Load Calculation
Total Load = IT equipment + CRAC/air conditioning + lighting + auxiliary equipment
Recommended sizing: 1.25–1.5× peak load to prevent low-load carbon buildup
2. Generator Type
Standby: for short-term emergency backup; lower cost
Prime/Continuous: long-duration operation, high reliability
Synchronous alternator: preferably permanent magnet for higher efficiency
Modular design: multiple units can operate in parallel for scalability
3. Brand & Quality
International brands: Caterpillar, Cummins, Perkins, MTU, Baudouin (high reliability, higher cost)
Local/Regional alternatives: verify long-term stability and service support
4. Installation Environment
Space: allow 1.5× unit dimensions for maintenance
Cooling: independent intake/exhaust; ambient ≤40°C
Noise: silent enclosures or custom acoustic rooms
5. Parallel Operation
Units must support load-sharing
Control systems must allow automatic synchronization and load distribution
6. After-Sales Service
Prefer suppliers with local service network
Maintenance contracts covering filters, oil changes, and load testing
7. Other Considerations
Future expansion: size units to allow growth without immediate upgrades
Monitoring system: ensure long-term stable operation
Cost optimization: balance compliance with international standards and budget constraints
Environmental compliance: meet local emission regulations
Conclusion
Selecting diesel generator sets for data center backup power requires balancing international standards compliance, performance reliability, load capacity, installation environment, and maintenance support.
Key focus areas: redundancy, fast start-up, fuel endurance, noise and emission control, and intelligent monitoring systems.
Properly designed backup power ensures continuous, stable, and efficient operation of data centers worldwide.
