Every large data center’s power supply begins with a connection to the main grid provided by the local utility company. Typically, data centers are connected to at least one diesel or gas backup generator to ensure uninterrupted operation in the event of a large-scale power outage. Medium voltage is supplied from both the local utility provider and the backup generator.

Main Distribution Boards (MDBs), which are panels or enclosures housing fuses, circuit breakers, and ground leakage protection units, take and distribute low-voltage electricity to endpoints such as Uninterrupted Power Supply (UPS) systems or load banks.

MDBs also monitor incoming energy from the main grid and, upon sensing a power outage, activate the backup generator. Most data centers store enough fuel to keep the generator running for 24–48 hours.

Instead of directly distributing low-voltage electricity to sensitive computer components, MDBs pass power through a UPS system. The UPS provides short-term power when the input source fails and protects critical components from voltage spikes, harmonic distortion, and other common power issues.

Most UPS systems are designed to supply power to the maximum load during an outage for at least 5 minutes. During this time, backup generators have sufficient opportunity to start and take over the load from the UPS system.

This outline of a common data center power infrastructure demonstrates how modern data centers ensure reliable power to meet the growing demand for connected IT solutions and how backup power ensures smooth operation across the entire facility.