UPS capacity question

[bobbob]

I'm designing my first system, and would like some help on how large of a UPS is needed, I'm doing a Supermicro x11 system with the capacity to power as many as 14 hard drives. Based off the power calculations it will have an 850w PSU (total peak = 582 + 25% = 738).

All I want from the UPS is to shutdown the system safely. I will manually restart it. I would like to get the smallest UPS as possible, but with a high margin of safety. Based on the APC's UPS Selector widget, a 1000VA/600W unit will give 5 min of runtime for a 500W load. My gut tells me that this would be more than sufficient, but I really have no idea if its on the edge, or need to go bigger and accept the higher maintenance costs (e.g. batteries for the APC BR1000G (600W) and BR1500G (865W) are roughly $40 and $70 respectively).

I apologize for this really really stupid post (I'm quibbling over $30 every year or two). But I've only owned one UPS in my life. It was an APC purchased 2 decades ago. It was buggy, loud, and the battery was around $250 a pop (lasted a year if lucky). Over the years apparently I've developed UPS hatred. I don't care if its only a $30 difference. I'd like to get the smallest UPS possible. Any input would be greatly appreciated - Thanks!

edited: removed UPS selector widget link (it gets redirected and probably confusing).

 

[joeschmuck]

Well selecting an UPS means you need to ask yourself a few simple questions...

1) Do you live in an area with frequent power issues?
2) How long do you want the UPS to keep your system operational before shutting down?
3) How much power will your computer system pull from the UPS?

Given the information you provided I think a 1000VA UPS is fine. I have an APC Back-UPS Pro BR1000G and it works flawlessly with FreeNAS. Most APC units will work flawlessly. There are other brands as well out there which work fine but I don't have personal experience with them, and I've always had a soft spot for APC. As for battery replacement costs, you get what you pay for. If it's a good deal then it's probably too good of a deal. I just had my first APC UPS failure, it lasted over 15 years. I replaced the batteries twice in that time period. I could have purchased lesser batteries but I did not. I didn't buy batteries from APC either because they were crazy expensive but I did ensured I purchased good quality ones.

So a 1000VA UPS should keep your system running about 10 minutes, maybe a little bit longer. If you live in an area with a lot of power issues then set your UPS to turn off with 5 minutes remaining vice turn off after on UPS for 5 minutes. It's a battery charging thing.

Hope this helps.

EDIT: If the BR1500G is only $40 more expensive, buy it! I believe the physical size is the same.

 

[bobbob]

Thanks for the feedback - it was helpful.