SMV2000CAI excessive output voltage trims

[Bornecu]

Hi all,

I have a SMV2000CAI UPS for which I already changed the batteries once. I am logging data from most of its sensors with Home Assistance, including UPS input/output voltage, frequency, etc. I noticed in the data logs for the last two months significant voltage cuts in the UPS output when the grid voltage (input V) goes above 240V  (grid nominal voltage is 230V). See below some screenshots from Home Assistant with the recorded input and output voltage of the UPS.

The voltage trim that the UPS does is almost 40V, pulling down the output V to 200V, which I find a bit worrying. Is this a usual behavior for UPS or there is something wrong in the way the voltage is trimmed? Is this kind of behavior fixable?

In general you can see that the output voltage is always lower than input, even when the input voltage is at or close to nominal parameters.

[Teken]

This specific APC UPS model doesn’t appear to have the usual adjustments such as sensitivity and upper / lower transfer voltage thresholds?!? ☹️

I would check to see if the included software package allows you to adjust when the unit goes into battery only mode along with the AVR Trim / Boost.

Keep in mind neither will resolve this specific issue of the unit trimming the output voltage by 40 VAC! 🤦‍♂️

If the unit is still under APC Warranty I would suggest you contact APC Technical Support to confirm if this is the expected behaviour vs a defect in the hardware.

All of the enterprise units I have don’t drop by more than 10-15 VAC. I’ve only seen this on the lower end units made by APC in their Back-UPS line.

Let me know how it all turns out with APC Technical Support. 👍

[Bornecu]

Unfortunately I contacted several times APC Tech Support and described the problem but I didn't get any feedback from them. They don't seem to be responsive nor interested in this.

Unfortunately this issue still persists (even this morning at 7am it trimmed output below 200V, when grid voltage was above 240V).

I am thinking now whether the batteries may be the issue..

 

[Teken]

Create a service request with APC Technical Support and have the unit RMA’d.

Let me know the outcome good / bad. 👍