Why does the SNMP value reading from upsAdvOutputCurrent show 0 A with small loads attached to Smart UPS products?

Issue

Why does the SNMP value reading from upsAdvOutputCurrent show 0 A with small loads attached to the Smart UPS?

Product Line

• UPS Network Management Card 1 (NMC1) - AP9617, AP9618, AP9619
• UPS Network Management Card 2 (NMC2) - AP9630/AP9630CH, AP9631/AP9631CH, AP9635/AP9635CH
• Various Smart UPS models

Environment

• All serial numbers
• All firmware versions
• SNMP users
• Users with small UPS loads

Cause

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.


Resolution

We recommend to query other SNMP values such as upsAdvOutputLoad, which gives a more accurate rating of the load in %.