How to Confirm UPS Capacity Requirements?

When purchasing UPS system for equipments, you need to consider how to confirm UPS capacity requirements or what kind of UPS is the best. Baykee has rich experience in UPS application and theory research. Read the following article, and get some useful tips.

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Estimating Capacity Requirements

If the total current drawn by connected equipment exceeds the UPS system’s capacity, the UPS becomes overloaded. If the UPS is overloaded, it will drop the load during an outage instead of switching to battery mode. You can estimate 

your UPS capacity requirement by totaling the wattage requirements of all the equipment you plan to connect to the UPS system. You should refer to the equipment manufacturer’s documentation to find the wattage. If you can’t find any printed or online documentation, refer to the equipment nameplate. If your equipment lists its power requirements in amps, multiply the number of amps by the AC voltage to estimate wattage.

Refer to the UPS specifications to find models with capacities higher than your total wattage requirement. UPS systems are typically marketed by their VA rating, but the capacity in watts should also be listed. (Keep in mind that UPS manufacturers typically recommend limiting IT equipment loads to 80% of capacity. This helps the UPS handle fluctuations in power demand, leaves headroom for additional equipment and reduces the chance of overloads. )

Note: Although this method will provide a rough estimate of your UPS capacity requirements, we recommend that you confirm your estimate with the UPS manufacturer or reseller.

High-Capacity Applications 

If your capacity requirement exceeds 16,000 watts, you may wish to consider a 3-phase UPS system, or you can divide your equipment into smaller groups to be supported by multiple single-phase UPS systems. (If your equipment is distributed across a wide area, multiple single-phase UPS systems may be required regardless.) 3-phase power costs more to install than

single-phase power, but it can be more efficient for high-capacity loads.

High Power Factor 

Some network/server UPS systems have a high power factor that makes more efficient use of your facility’s power infrastructure and available space, allowing you to connect more equipment to each UPS system and circuit. While a 10,000 VA UPS with a 0.7 power factor will support a 7,000-watt load, a 10,000 VA UPS with a 0.9 power factor will support a 9,000-watt load, an increase of 2,000 watts without a corresponding increase in circuit requirements.