Three-phase load balancing occurs when the loads of power supplies, such as a three-phase rack PDU, are spread evenly across all three phases (L1/L2, L2/L3, and L3/L1).
It can be achieved by having an equal number of devices plugged into PDU outlets for each phase and drawing an equal power load on each phase. Some manufacturers provide three-phase PDUs with alternating phased power on a per-outlet basis rather than per-branch.
Three-phase load balancing is desirable because an unbalanced system can result in reduced efficiency, tripped circuit breakers, and reduced useful life of equipment.
Advantages of Balanced Three-Phase Power
- Increased utilization of the upstream electrical infrastructure capacity, resulting in improved overall data center efficiency and can delay capital expenditures.
- The ability to support significantly higher power density in comparison to a single-phase circuit with similar amperage.
- Maintain power factor of the incoming power and avoid penalties imposed by the utility.
- Scalability for future load requirements.
- Fewer whips and cables required, resulting in less airflow obstructions, a cleaner work environment, and easier installation and maintenance.
- Extend the useful life of equipment.
Three-Phase Power Monitoring with DCIM Software
Power calculations for three-phase power systems can become significantly more complicated when the load is out of balance. This occurs when the load current between any two lines is significantly different than the load current between the remaining line. When there is an unbalanced load, the efficiency of the system and the amount of power being delivered will be reduced. Suppliers of three-phase power intelligent rack PDU provide local current load meters for each phase on the PDU, making it much easier to monitor and balance the power than having to perform manual calculations.
It is best practice to use Data Center Infrastructure Management (DCIM) software to monitor power consumption and capacity. Modern DCIM software has three-phase imbalance alerts for all facility equipment, including rack PDUs, floor PDUs, UPSs, RPPs, meters, and busways. Previously an extremely difficult task to accomplish, data center managers now have an easy monitoring solution that automatically calculates percent imbalance and alerts them of any imbalance in the power path based on configurable thresholds. Users can report on the live three-phase current readings and percentage imbalance.
Want to see how Sunbird’s world-leading DCIM software dramatically simplifies three-phase load balancing? Get your free test drive now!