Smart-UPS 3000 - rapid change of input

[Marine_Mike]

Hi. We have a Smart-UPS 3000 (SMT3000RMI2U) with an NMC 3 fitted. Last week it reported the following:

09/10/2024 17:48:01 Device UPS: The output power is turned off. 0x0114
09/10/2024 17:48:01 Device UPS: The graceful shutdown period has ended. 0x014F
09/10/2024 17:48:00 Device UPS: The power for switched outlet group 1, Outlet Group 1, is now turned off. 0x0135
09/10/2024 17:48:00 Device UPS: The power for the main outlet group, UPS Outlets, is now turned off. 0x0135
09/10/2024 17:48:00 Device UPS: An automatic voltage regulator (AVR) relay fault exists. 0x0126
09/10/2024 17:47:58 Device UPS: No longer on battery power. 0x010A
09/10/2024 17:31:59 Device UPS: On battery power in response to rapid change of input. 0x0109

At this point someone had to attend the site, where it was alarming. Once the UPS has been powered off and on again it recovered as follows:

09/10/2024 20:10:37 Device UPS: The power for switched outlet group 1, Outlet Group 1, is now turned on. 0x0134
09/10/2024 20:10:35 Device UPS: The power for the main outlet group, UPS Outlets, is now turned on. 0x0134
09/10/2024 20:10:34 Device UPS: The output power is now turned on. 0x0113
09/10/2024 20:10:31 Device UPS: Switched outlet group 1, Outlet Group 1, has been commanded to turn on, sequenced. 0x0174
09/10/2024 20:10:31 Device UPS: Main outlet group, UPS Outlets, has been commanded to turn on, sequenced. 0x0174
09/10/2024 20:10:10 System Email: Could not resolve 'mailrelay.xxxxx.co.uk'. 0x001A
09/10/2024 20:10:10 Device UPS: An automatic voltage regulator (AVR) relay fault no longer exists. 0x0127

I've got the following questions, can someone please assist:

1. is there any way we can determine the cause of the fault? It sounds like it could be down to the input voltage, however we would like to be certain if possible.
2. is there a reason it didn't recover itself once the fault condition was no longer present? Maybe our configuration needs to be amended?
3. is it possible there is a latent fault with the AVR, and the UPS will ultimately need repairing?

Best regards,

Mike

[Teken]

Hi Mike,

Please call out how long the unit has been in service along with the serial number. Has the battery ever been replaced on this system?!?

Lastly, the AVR Relay Fault is very common failure mode and does indicate the system will begin to operate erratically. ☹️

You may do some basic validation checks if so equipped. 

Default: If the system has been customized as it relates to the power quality and transfer voltages. You may default the unit to its factory settings via the LCD Menu.

Self Test: Manually initiate a self test of the unit either through the LCD Menu, NMC, Power Chute Software. What are the results of doing so?!?

Battery Calibration: If the batteries are more than 4 years old this test must be done with great care! As doing so on a marginal battery pack / cartridge will immediately shut down the entire system. 

As such the connected loads must not be critical loads your company relies on. ☝️ You may connect any resistive load that places at least 30% load on the system.

AVR: There is no way to test the AVR circuit without a variable transformer such as this one:

https://a.co/d/7gWA5up

Using such a device will immediately tell you if the AVR circuit is operating correctly based on the user defined transfer voltage settings.

Meaning if you increase / decrease the input voltage using this device. The UPS should trim / boost the output to compensate for the improper line voltage.

This test must be performed with and without a connected load! One is called a static test vs dynamic test.

The static test has no connected loads attached to the UPS outputs. Whereas the other one does. This test must be performed no less than five times over several hours to determine and validate the system operates as designed and intended.

We do the same tests on all our systems as part of the validation process and long term performance analysis.

Let me know if you have more questions and the results of the AVR tests. 👍

[Marine_Mike]

Thanks for your reply, I'll let you know once I have more information to share.