Nothing more than anything is having to look up a password for a device and not using my central admin account for logging into a devices. Here is how to configure Windows NPS to authenticate APC UPC devices.
NPS Network Policies:
Now you have a working Network Policy
Shared Secrets Template:
As you will have a bunch of UPS to add to NPS I would create a Shared Template for easy addition of devices.
Radius Client Add:
APC UPS Configuration:
Configure RADIUS Server IP and Secret that you created on the NPS server. I also noticed my password was too long to test the settings. I just Skip Test and Apply. You can always disable the host on the NPS server if you make a mistake or use the local account.
That is how you configure APC UPS to use NPS for centralized authentication.