Windows receives the shutdown command a minute later than PowerChute calls it

[Anonymous user]

We had a power outage today and PowerChute didn't seem to work properly. Colleagues, I ask you to help me understand why this happened. To understand the situation, I compared the PowerChute and Windows logs, and saw a discrepancy.
There is an event in the PowerChute logs:
08:46:39 Shutdown process started
There is a corresponding event in the Windows logs:
8:47:44 The process wininit.exe (127.0.0.1) has initiated the power off of computer HSERVER on behalf of user NT AUTHORITY\SYSTEM for the following reason: Legacy API shutdown.
Thus, we see that for some reason the server received the shutdown command more than a minute later than it was generated by PowerChute. Because of this, the server did not have time to completely shut down. Why did this happen?
My equipment: Smart-UPS 750 connected to the server via COM port, Supermicro SYS-5038R-T server, Microsoft Hyper-V 2012 R2 operating system (core).
My config: 

Time Required For Shutdown Sequence 15 Minutes
Low Battery Signal 2 Minutes
Command File Enabled No
OS Shutdown Duration 1:30 Minutes:Seconds
OS Shutdown Type Shutdown and Off
Enable OS Reboot Yes
UPS Turn On Battery Capacity 0 %
UPS Turn On Delay 1 Minutes
Enable SMTP E-mail No
Enable Logging Yes

[BillP]

@Anonymous user 

When PowerChute starts the shutdown process it sends this command

shutdown /s /f /d UP:6:12 /c "PowerChute Business Edition has initiated a system shutdown."

If you want the system to shut down immediately change the shutdown command to 

shutdown /s /t 0 /c "PowerChute Business Edition has initiated a system shutdown."  /f /d UP:6:12 

By adding /t 0 there will be no delay.

The file to edit is in C:\Program Files (x86)\APC\PowerChute Business Edition\agent\bin and is named shutdown 

To test the command open a command prompt as an administrator and you can run each command to see the difference. 

When you run shutdown /s /f /d UP:6:12 /c "PowerChute Business Edition has initiated a system shutdown." a pop appears warning you the system is going down. 

When you run shutdown /s /t 0 /c "PowerChute Business Edition has initiated a system shutdown."  /f /d UP:6:12  There is no warning and the system powers off immediately.