Do I have the correct UPS for this computer?

[BillP]

I maintain a PowerMac G5 2.0 Ghz dual processor 1.5gb RAM 10.3.9 OS 149 gb hd CD-RW/DVD-RW computer. It is using a UPS BK350 serial # BB0321008995. When there is a power surge, the computer fans will sound like "jet engines" and not kick out of this phase and the computer will lock up. My question is: is the battery that I have connected to this computer too small? And if so, what is the recommended size for G5 and G4 dual processor computers? I have other computers using the same size UPS, same software, everything is generally the same for these computers and a couple of them will turn off unexpectedly-not go into battery backup mode. They won't do the "jet engine" fan sounds though. Can you help me here?

[Anonymous user]

I see two potential problems using this UPS with this computer. PowerMac's generally require a pure sine wave input. When the BK350 transfer's to battery it outputs a step approximated sine wave which I assume is causing the excessive fan noise. Secondly, this UPS is undersized. Looking at the tech specs posted on Mac's website: http://support.apple.com/specs/powermac/Power_Mac_G5_Late_2005.html it shows the PowerMac consuming up to 10 Amps. 10 amps X 120 V = 1200VA. This UPS is only capable of supporting 350 VA. I would suggest using a Smart-UPS which outputs a pure sine wave while on battery and increasing the capacity of the UPS.

[Anonymous user]

Thank you very much. I will definitely take this into consideration and update our UPSs because most of our computers have the same processors, software, etc.
Thanks again! :~)

[BillP · Accepted solution]

I maintain a PowerMac G5 2.0 Ghz dual processor 1.5gb RAM 10.3.9 OS 149 gb hd CD-RW/DVD-RW computer. It is using a UPS BK350 serial # BB0321008995. When there is a power surge, the computer fans will sound like "jet engines" and not kick out of this phase and the computer will lock up. My question is: is the battery that I have connected to this computer too small? And if so, what is the recommended size for G5 and G4 dual processor computers? I have other computers using the same size UPS, same software, everything is generally the same for these computers and a couple of them will turn off unexpectedly-not go into battery backup mode. They won't do the "jet engine" fan sounds though. Can you help me here?