The SNMP value upsAdvOutputCurrent reflects the current in amperes drawn by the load of the UPS.
In Smart UPS units, if the load connected to the UPS is less than one ampere, this value shows 0 A. This is due to the UPS units ability to measure small loads accurately. With small loads, the rate of accuracy is low. With a larger load, the UPS will provide a more accurate load rating.
We recommend to query other SNMP values such as upsAdvOutputLoad, which gives a more accurate rating of the load in %.