Overclock.net › Forums › Components › Power Supplies › PSU-PFC and UPS Question
New Posts  All Forums:Forum Nav:

PSU-PFC and UPS Question

post #1 of 9
Thread Starter 
I am throwing out the below statement from a post on a flightsim forum I belong to. I would like to know from the OCN PSU Guru's if there really is a compatibility issue between the PFC function in new PSU's and some UPS.

Please read the below and let me know what you think! My current PSU is a Corair AX850 and my UPS is a year old APC unit.

"I've done some further research and believe I've found compatibility issue between the PSU and UPS.

Since my Seasonic has active PFC and my current UPS does not have true sine wave output the PSU may be shutting the system down (or suspending it). Never had this issue with with old PSU because it did not have active PFC."
My System
(14 items)
 
  
CPUMotherboardGraphicsRAM
4770K @ 4.7GHz / 4400MHz Asus Sabertooth Z87 Gigabyte GTX 780 OC 8GB G.Skill Trident X 9-11-11-31-1T @ 2400MHz 
Hard DriveOptical DriveCoolingOS
OS SSD 840 Pro 256GB / FSX SSD 840 Pro 256GB LG DVD Thermalright SB-E x2 Win7 Ult 64b 
MonitorKeyboardPowerCase
Viewsonic VP2655wb 25.5" IPS LCD Logitech Wireless EX1110 w/Mouse Corsair AX860i CM HAF-X 
  hide details  
Reply
My System
(14 items)
 
  
CPUMotherboardGraphicsRAM
4770K @ 4.7GHz / 4400MHz Asus Sabertooth Z87 Gigabyte GTX 780 OC 8GB G.Skill Trident X 9-11-11-31-1T @ 2400MHz 
Hard DriveOptical DriveCoolingOS
OS SSD 840 Pro 256GB / FSX SSD 840 Pro 256GB LG DVD Thermalright SB-E x2 Win7 Ult 64b 
MonitorKeyboardPowerCase
Viewsonic VP2655wb 25.5" IPS LCD Logitech Wireless EX1110 w/Mouse Corsair AX860i CM HAF-X 
  hide details  
Reply
post #2 of 9
Sometimes, but there's no way to tell unless a given PSU/UPS combo is tested as bad.
post #3 of 9
UPS have both maximum Watt ratings and maximum VA ratings. It is a de-facto standard in the industry that the Watt rating is approximately 60% of the VA rating for small UPS systems, this being the typical power factor of common personal computer loads.

Power Factor Corrected supplies have the character istic that the Watt and VA ratings are equal power factor of 0.99 to 1.0. Capacitor Input supplies have the characteristic that the Watt rating is in the range of .55 to .75 times the VA rating power factor of 0.55 to 0.75.

Common mistake people make. Get a UPS 1.5 times your output and you wont be in trouble of overloading it or getting strange noises of your psu
Edited by Spooony - 5/14/11 at 2:17am
post #4 of 9
Thread Starter 
Quote:
Originally Posted by Spooony View Post
Common mistake people make. Get a UPS 1.5 times your output and you wont be in trouble of overloading it or getting strange noises of your psu
Are you saying that if I have a 850W PSU then I need a UPS rated at 1275W? My current one is only rated at 450VA/330W.
My System
(14 items)
 
  
CPUMotherboardGraphicsRAM
4770K @ 4.7GHz / 4400MHz Asus Sabertooth Z87 Gigabyte GTX 780 OC 8GB G.Skill Trident X 9-11-11-31-1T @ 2400MHz 
Hard DriveOptical DriveCoolingOS
OS SSD 840 Pro 256GB / FSX SSD 840 Pro 256GB LG DVD Thermalright SB-E x2 Win7 Ult 64b 
MonitorKeyboardPowerCase
Viewsonic VP2655wb 25.5" IPS LCD Logitech Wireless EX1110 w/Mouse Corsair AX860i CM HAF-X 
  hide details  
Reply
My System
(14 items)
 
  
CPUMotherboardGraphicsRAM
4770K @ 4.7GHz / 4400MHz Asus Sabertooth Z87 Gigabyte GTX 780 OC 8GB G.Skill Trident X 9-11-11-31-1T @ 2400MHz 
Hard DriveOptical DriveCoolingOS
OS SSD 840 Pro 256GB / FSX SSD 840 Pro 256GB LG DVD Thermalright SB-E x2 Win7 Ult 64b 
MonitorKeyboardPowerCase
Viewsonic VP2655wb 25.5" IPS LCD Logitech Wireless EX1110 w/Mouse Corsair AX860i CM HAF-X 
  hide details  
Reply
post #5 of 9
Quote:
Originally Posted by Spooony View Post
UPS have both maximum Watt ratings and maximum VA ratings. It is a de-facto standard in the industry that the Watt rating is approximately 60% of the VA rating for small UPS systems, this being the typical power factor of common personal computer loads.

Power Factor Corrected supplies have the character istic that the Watt and VA ratings are equal power factor of 0.99 to 1.0. Capacitor Input supplies have the characteristic that the Watt rating is in the range of .55 to .75 times the VA rating power factor of 0.55 to 0.75.

Common mistake people make. Get a UPS 1.5 times your output and you wont be in trouble of overloading it or getting strange noises of your psu
I think he was referring to a different issue, that of UPSs with simulated sine wave output causing issues with PSUs with certain active PFC implementations that require real sine wave input.
post #6 of 9
Quote:
Originally Posted by idahosurge View Post
Are you saying that if I have a 850W PSU then I need a UPS rated at 1275W? My current one is only rated at 450VA/330W.
no you have to try and determine first what is your output. Although your psu is rated 850 doesn't mean your pulling 850w. So you have to work in some headroom.
Now to get the watt for the ups you take 60 percent of the va rating. That's its watt rating. So if the va is 1300va the watt will be 810watt its rated. So be safe get it a bit higher than the 850w it will last longer aswell
post #7 of 9
Quote:
Originally Posted by Phaedrus2129 View Post
I think he was referring to a different issue, that of UPSs with simulated sine wave output causing issues with PSUs with certain active PFC implementations that require real sine wave input.
see the problem is not the sine wave is either people not getting the va rating and total output power and ends up with a under powered ups or they choose brands which is not the best of quality and is noisy aswell. A ups won't have problems with a psu unless the psu is not getting what his asking.
post #8 of 9
Thread Starter 
Quote:
Originally Posted by Phaedrus2129 View Post
I think he was referring to a different issue, that of UPSs with simulated sine wave output causing issues with PSUs with certain active PFC implementations that require real sine wave input.
This is what the original question was in regards to.
My System
(14 items)
 
  
CPUMotherboardGraphicsRAM
4770K @ 4.7GHz / 4400MHz Asus Sabertooth Z87 Gigabyte GTX 780 OC 8GB G.Skill Trident X 9-11-11-31-1T @ 2400MHz 
Hard DriveOptical DriveCoolingOS
OS SSD 840 Pro 256GB / FSX SSD 840 Pro 256GB LG DVD Thermalright SB-E x2 Win7 Ult 64b 
MonitorKeyboardPowerCase
Viewsonic VP2655wb 25.5" IPS LCD Logitech Wireless EX1110 w/Mouse Corsair AX860i CM HAF-X 
  hide details  
Reply
My System
(14 items)
 
  
CPUMotherboardGraphicsRAM
4770K @ 4.7GHz / 4400MHz Asus Sabertooth Z87 Gigabyte GTX 780 OC 8GB G.Skill Trident X 9-11-11-31-1T @ 2400MHz 
Hard DriveOptical DriveCoolingOS
OS SSD 840 Pro 256GB / FSX SSD 840 Pro 256GB LG DVD Thermalright SB-E x2 Win7 Ult 64b 
MonitorKeyboardPowerCase
Viewsonic VP2655wb 25.5" IPS LCD Logitech Wireless EX1110 w/Mouse Corsair AX860i CM HAF-X 
  hide details  
Reply
post #9 of 9
Quote:
Originally Posted by idahosurge View Post
This is what the original question was in regards to.
Yip but I explained what the real issue. Pfc supplies got a power factor of 1 coz the waves are in phase. Its not the power that gets supplied but the device supplying it not up to it or of very bad quality. That's more of the issue than clean power the psu might have problems with.

Phaedrus already answered that question with depends on psu depends on psu. You can imagine a quality psu with a low end ups? Some people forgot to connect the APC units batteries even coz they come out the box with batteries disconnected and use it for a considerable time where the ups or psu start to make horrible noises. Simple things like that.

Just to give you a example. This site uses ups with their psu testing.
http://translate.google.com/translat...Ftower%2F28176

You notice a bigger ups is advised and the ones with a watt output close to the psu output shuts down.
Edited by Spooony - 5/14/11 at 6:08pm
New Posts  All Forums:Forum Nav:
  Return Home
  Back to Forum: Power Supplies
Overclock.net › Forums › Components › Power Supplies › PSU-PFC and UPS Question