Data Center White Paper: The Importance of Generators in Data Centers

Overview

The paper treats the generator as a holistic system rather than a single machine. It lists the set and all its auxiliaries, site conditions, installation, commissioning, maintenance and spare-parts supply as the factors that decide reliability. Fast start is not accepted as a sufficient criterion on its own; the weakest link in the chain determines the outcome even when the engine itself performs well.

The technical framing rests on three points. First, the generator must start and pick up load before the UPS stored energy runs out, because UPS autonomy is limited. Second, whatever the rating class (DCP, Prime or Standby), the complete set of engine, alternator, radiator, controls and starting system is expected to conform to ISO 8528. Third, block water heaters are fitted as standard, while a backup starter, a backup electric starter and backup battery systems are options.

For plant-room design the paper names ventilation back pressure, room temperature rise and its effect on equipment, and exhaust back pressure, and recommends verifying them with 3D flow simulation. Tier IV allowable downtime is cited as about 0.8 hours per year. The text is largely qualitative with limited numeric content; it reflects a manufacturer's viewpoint and gives no calculation method or acceptance values.

Key points

1. Tier IV allowable downtime is cited as about 0.8 h per year.
2. The generator must start and take load before UPS stored energy is exhausted; UPS autonomy is limited.
3. Regardless of DCP, Prime or Standby rating, the complete set of engine, alternator, radiator, controls and starting system should conform to ISO 8528.
4. Reliability is not limited to fast start; the set, auxiliaries, site, installation, commissioning, maintenance and spare parts are assessed together.
5. Block water heaters are standard; backup starter, backup electric starter and backup battery systems are offered as options.
6. Plant-room ventilation back pressure, room temperature rise and exhaust back pressure are verified with 3D flow simulation.
7. Mechanical and vibration verification is treated as part of the holistic approach.

Using it in design

• Compare the generator start-plus-transfer time with UPS autonomy and show the margin in the design file.
• Calculate room ventilation airflow against the radiator requirement, the room temperature rise and the external static/back-pressure limits.
• Check exhaust back pressure against the limit on the manufacturer datasheet.
• For Tier III/IV targets, treat the block heater as default and add options such as redundant starters and batteries to the checklist.

Who should read it

Electrical designers preparing generator rooms and standby power schemes, and the operations and commissioning teams behind them.

Related standards

• ISO 8528-1
• ISO 8528-5

Publication details

Authors

Teksan

Publisher

Teksan

Year

2020

Document language

English

Source type

Manufacturer

Access

Free to read

Licence

Copyright retained; citation only — the publisher’s terms apply to the original document

Citation