ES 350 restarting PC

[Anonymous user]

Trying to isolate a problem we're having with our APC Back UPS ES. I don't think this is computer-related as it also did it with our Windows PC. I am now running our Powermac G5 off of the APC and, on occasion, the computer will restart on its own, with no evident power outages or surges, etc. I think this happened both when the USB was connected and when it was not. Does this sound like a problem with the unit itself? The battery is apparently at 100% charge, according to the OSX (Energy preference panel). Any ideas?

[Anonymous user]

Macs PSUs and many PSUs are now coming out with Active PFC and these PSUs require a lot of power when they are turned on. Since it takes a few milisencods to go from the energy coming out of the wall outlet to the energy coming out from the battery, you're making the PSU "turn off" for a few miliseconds and then back on again. This can make the PSU draw a lot of power and the UPS may become overloaded. Some PSUs are also very sensitive to the time delay it takes to go to battery power, so I recommend you choosing the Smart UPS series that has a faster battery switching time and produces pure sinewave - some PSU's are also sensitive to approximated sinewave produced by cheap UPSes.

Ithink the least thing you should do now is to buy a more powerfull UPS, since you MAC can draw much more power than your 350VA UPS can deliver.

What is happening in you case is that there is no need for power to completely go out for the UPS to switch to battery. Sags and overvoltages can do this. Some UPSes let you change its sensitivity so it stops going to battery because of small voltage sags. I always let mine at the lowest setting, since all my PSUs can deal with more severe voltage sags.

Message was edited by: rau

[BillP]

Macs I find are a lot more like servers - thus they can reboot when they see the step approximated sine wave that is outputted by the Back UPS line while on battery. Some also dont like the transfer time to battery which for this model is somewhere around 4-6 or 8 ms or so.

For servers, and high end macs, we usually recommend - like Rau said, something with more VA - usually a minimum of 800VA I'd say and certain mac's will require a pure sinewave output (like a wall outlet provides) and a lower transfer time to battery - 2-4ms or even 0ms.

Our Smart UPS line outputs a pure sinwave, has ALL battery+surge protection outlets and has a transfer time to battery of 2-4ms.

You can view them here but as you can see, they are a bit more expensive.

Some mac's need a smart ups, others can deal with it. So at a minimum, I'd try something with more VA in the Back UPS line - maybe a BR800BLK model or BR1200.

The ES 350 you have only provides ~200 watts.

[BillP]

One note about Macs: While any of the Power Mac or Mac Pro tower form-factor PCs are high-end, workstation/server class professional computers, other Macs like the iMac (any generation/form factor) or Mac mini have power requirements similar to the average home PC.

It's very common for customers with the Power Mac or Mac Pro systems to report difficulties with their APC Back-UPS. This is to be expected since these computers often do use PFC and usually overload smaller Back-UPS units. This is similar to the issue we're seeing in this discussion.

[BillP · Accepted solution]

Hi,

What is your configuration like? What's plugged into the UPS and where? Are you using any power strips/extensions before or after the UPS?