When the UPS and these devices are in normal operation, if the real-time total power of the device is equal to the rated power of the UPS, then the UPS is fully loaded. If the rated power of the UPS is exceeded, the UPS is overloaded. Just like the load of a car, if it just reaches the limit weight, it is fully loaded, and if it exceeds it, it is overloaded.
The rated output power is an important parameter that indicates how much power the product can drive. It varies with the load power factor. For example, a 1kVA UPS may not be able to drive a 1kVA load. In order to prolong the service life of the UPS power supply, the UPS power supply should not be used. Run under full load for a long time.
The backup UPS generally selects the load of 60% - 70% of the rated power, and the online UPS generally selects the load of 70% - 80% of the rated power. At the same time, it is not suitable to operate under excessive light load for a long time.
UPS uninterruptible power supply should not be fully loaded or excessively lightly loaded. Each unit is marked with rated power. Under normal circumstances, online UPS should not exceed the load of 80% of rated power. Therefore, it is best not to use it according to the nominal rated power. In a fully loaded state, it will cause overheating of the inverter and rectifier, affecting the service life.
Likewise, it is not advisable to operate under an excessively light load, because an excessively light load may cause a deep discharge of the battery during a power outage, which will also significantly reduce the service life of the battery. For some special loads, a strong inrush current will be generated during the starting or working process, and the load capacity will instantly increase several times (sometimes as high as 6 times). For this kind of load, the margin should be further increased on the basis of the ordinary capacity margin ratio.
To sum up: UPS is neither suitable for long-term full-load operation, nor long-term light-load operation. The former is easy to cause damage to the inverter and rectifier of the UPS power supply, and the latter is easy to damage the battery of the UPS. Therefore, the single UPS should be configured according to the load capacity of 60% to 80%, and the parallel machine should be configured according to the load capacity of 35% to 40% of each unit.
