PC Reboots When Switching to UPS

[Anonymous user]

Hello,
I have just built a new PC. Gigabyte EP35-DS3R, E6600, Antec Earthwatts 500 PS, XP Pro SP3. I have a Back-UPS 650 (BE650BB). I am running Powerchute personal 2. As stated in the title, if I pull the UPS plug from the wall outlet, or there is a power outage, rather than switching to UPS power immediately, the PC reboots then runs on UPS power. The UPS has been working fine on the PC I just replaced (Asus A8N-E Opteron 175, Antec TruePower 2 480 PS). The new system draws much less power. I have contacted APC, Antec, and Gigabyte and no-one has any answers. It does not matter if I am booted into the OS or sitting with the BIOS screen displayed, when I pull the plug the PC reboots. The battery is 100% charged and has been regularly passing self tests.
Please Help.

[Anonymous user]

Thank you all for helping. That last link is definitely very helpful. Does it mean that I don't worry about the "up to 8ms switching time" and getting a larger unit should solve my problem?

[Anonymous user]

That's good to know cos I was telling people who were having the same issue to exchange their UPS for higher VA ones, but it seems this is not the only issue.

Is there a way to produce more affordable pure sine wave units or at least smaller ones, like 500 to 600VA? In my country the smart ups units are ridiculously expensive. With Active PFC PSUs becoming a common thing, pure sine wave UPSses should become cheapper or less "fancy" units for the residential market should be made, I think.

Thank god I don't have any issue on a Zalman 460watt. At least not yet! Apart from the buzzing noise coming out of it while on battery, it works well with the 8ms typical transfer time on a 600VA Backup ES unit.

[EZ_Button_apc]

Sounds like your system is sensitive to the transfer time of the UPS. A back-ups will have a 4-8 second transfer time to battery. It's generally not a problem for power supplies, but you never know. I'd try getting in touch with your power supply manufacturer and finding out if it can handle momentary power drops of a few milliseconds. APC makes other UPS's with less or no transfer time to battery (Smart-UPS and Smart-UPS RT), but unfortunately, they are more expensive.

[Anonymous user]

I believe you meant 4 to 8ms, not seconds!

I think this might be helpful:

http://emea-en.apc.com/cgi-bin/emea_en.cfg/php/enduser/std_adp.php?p_faqid=8883&p_created=1193079387...

[Cap1_apc]

I think your best bet would be the Smart-UPS line for a PFC power supply. I've personally seen cases where not only does the PS overload the unit, but also ones where the 8 millisecond transfer actually drops the load. The overload scenario is more likely, but I would see if your PS manufacturer can elaborate on the lag time the PS can sustain.

The Smart-UPS line essentially takes care of both of these issues:
- It transfers in 2-4ms
- It can sustain a brief overload much better than the Back-UPS line

[Anonymous user]

So I went out and bought a BX1300LCD which is 780 watts. Same issue exists. Maybe the Smart Series is the only solution.

[Anonymous user · Accepted solution]

Problem solved. I purchased a cheap store brand at Circuit City. The brand is Nexxtech. Made in China. 3 year warranty. 1000 VA 600 W. It states on the box that the typical transfer time is 4ms.
It also states that it uses a simulated sine wave. Apparently the transfer time was my issue. $109.00 US. Probably can be had elswhere for cheaper.
So, APC won't be getting $300.00 or more dollars from me for a SmartUPS. Thanks to all who tried to help, and I hope this info will prove useful to others.