BN-1500 drops power for 1-2 seconds when AC restored?

[RichA]

I'm just now doing some testing of AC power fail, and my BN-1500 does a fine shutdown, including shutting down a Win 10 workstation on a 1 minute trigger.   

After 2-3 minutes of being off,  backup power is still going fine, I restore AC.  Then this happens: 

1.  surge outlets turn on

2. front panel continues to shows On Batt, minimal load (1 bar), batter is 3 of 4 bars, and 32 min power remaining (no indicator of AC yet)

3. Windows workstation is triggered and starts booting

4. about 10-20 seconds after AC restore, the BN-1500 front panel suddenly goes black for ~4 sec and all power outlets go off.

5. BN-1500 front panel comes back on, showing  On Line, minimal load, 4/5 battery bars, 121V.   

6. Windows starts rebooting again.  All other devices are in reboot after this power drop.

-->what's going on?   Why did BN-1500 drop power for 4 seconds after AC was restored?????

I have a video where I captured the front panel indicators!

[JonPro]

Hi @RichA 

Thank you for reaching out to the SE Community, my name is Jon and I will assist you with this query.  Apologies for the late revert, are you using PowerChute Personal Edition on your Windows PC while using the APC UPS?  If you are, did you use the Preserve Battery Power shutdown option?

If this was the option that you selected, please see the shutdown behavior below.

PowerChute Personal Edition default shutdown timeline:
1. UPS goes to battery and PCPE starts its preserve battery power counter.

2. When the counter expires it sends a command to the UPS to start counting its turn-off delay and then commands the OS to shut down.

3. The operating system shuts down and the UPS continues to count its turn-off delay. (Once the UPS finishes counting its turn-off delay it will reboot and nothing can stop this from happening.)

4. The UPS cuts power to the outlets and then rechecks to see if the incoming power is acceptable. If it is not it waits there until power returns.

5. If the UPS went to battery due to a brownout the unit at this point will be in low voltage sleep mode until the voltage becomes acceptable again.

You'd have to wait until the UPS enters the sleep mode before plugging the it back to the outlet.