Help with setup and Back-UPS information

[Microfiche]

Hey all, sorry if this is a bit long, but want to ensure I am not missing important details.
I have two APC UPS units, a Smart UPS 750 (SMT750) and a BackUPS Pro (BR1000MS).
These are protecting 2 Windows 11 computers, a QNAP NAS, a Raspberry Pi and a router.
Both UPS units are connected to the same power receptacle. I slapped together a diagram below.

As there is no network connectivity natively on these 2 UPS units, I have connected the Back-UPS to the Raspberry Pi via the USB serial cable, and the Smart-UPS to PC-2 via the USB serial cable.
I am running Powerchute serial shutdown on PC-2, with a script that shuts down PC-1 as part of the PC-2 shutdown process.

The Raspberry Pi connected to the Back-UPS is running NUT, and the QNAP NAS is connected to the Back-UPS over the network for shutdown purposes and also plugged into it.

PC-1 is plugged into the Smart-UPS, and PC-2 is plugged into the Back-UPS to balance the load between the UPS units and provide maximum run time. So yes, PC-1 will shut down if the Back-UPS loses power, even though it is physically plugged into the Smart-UPS.

Currently I have the Raspberry Pi and the router plugged into the Smart-UPS.
The only problem I had when testing the shutdown is that the Raspberry Pi and router are being shut down during the shutdown process on the Smart-UPS. I didn't realize that the outlets on the UPS are actually turned off during the serial shutdown process.

So what happens on the Back-UPS when power is lost and Powerchute serial shutdown is NOT connected?
Will the outlets stay powered as long as the battery has power? I can't find anything in the manual. If that is the case, I can plug the Raspberry Pi and the router into the Back-UPS instead and everything should work fine.

Also - assuming I don't want to invest more in a new network connected UPS, is this a reasonable solution?

[fredkm · Accepted solution]

PowerChute Serial Shutdown will turn off the outlet group powering the server as part of the shutdown process. In your setup this is PowerChute Serial Shutdown installed on PC-2 that will turn off the connected SMT750.

Your Back-UPS currently is not controlled by PowerChute Serial Shutdown, so it will keep powering connected equipment until the battery drains.

The new 1.3 version has an option in the Shtudown Settings page to not turn off the UPS, but this option is only made available for connected Back-UPS (and not Smart-UPS). SMT750 only has a single main outlet group which is always turned off during shutdown process. If you connect a higher-end Smart-UPS, with multiple outlet groups, you can configure PowerChute Serial Shutdown to include/exclude outlet groups from the shutdown process. This is great for secondary equipment you want to keep powered on.

So, what's the reasoning behind PowerChute Serial Shutdown turning off the outlet group powering the server you may wonder. On most Smart-UPS you can configure outlet groups to automatically turn on again when power is restored. This comes in handy when you configure your server to auto-restart after power outage. As soon as power returns, the UPS outlet group turns on, and your server will restart. Of course this will only work if the outlet group was turned off first. If the outlet group remains powered on during an outage then your server will not auto-restart if power returns.

[Microfiche]

Perfect - that is what I needed to know regarding the Back-UPS!

And yeah - I get why they set it to shut they shut the outlets off, I had just never thought about it before, as this type of situation had never come up. Appreciate the help! I have invested about as much as I care to in this system currently, so if this work, I don't have to buy another UPS! Yay!