Active PFC Power Supply Unit and APC UPS compatiibility

[ksipsi]

Hello,
I recently bought an APC BACK-UPS RS 1500VA 230V. After I had bought it i found out that there is a rumor in the Internet that this series of UPS is not compatible with PSUs that have Active PFC.
Is that so ?
Did anyone ever used this UPS with a UPS that was Active PFC ?
I have dual PSU configuration in my system, one is active PFC (Fortron FSP Epsilon 700W) and one that it is not so obviously I am concerned about the Fortron.
Any knowledge, and even better, any kind of experience about this will be much appreciated !

P.S. Sorry for any grammar mistakes...

[[XC] Angstrom]

You just need to find the UPS models that output a true sine waveform. The majority of the household ones are simulated sine - and that caused a problem with my Enermax Infiniti. It would cause the overload to trigger when first turning the PC on, even though there was no overload.

It still worked, except for the occasional overload trip on startup, but I can't imagine it would be good for the PSU.

[ksipsi]

OK i connected the UPS to my computer and everything went well. No smoke no explosion no burnt hardware at all!
The only thing is that when the UPS is operating on batteries the psu with the Active PFC makes a strange sound but it works though. Is this normal or is the sign of something bad happening ?

[Soulburner]

Hmm I have that UPS (but 1300) and no problems with my Corsair 620 or 520...

[xytrius]

OK i connected the UPS to my computer and everything went well. No smoke no explosion no burnt hardware at all!
The only thing is that when the UPS is operating on batteries the psu with the Active PFC makes a strange sound but it works though. Is this normal or is the sign of something bad happening ?

What kind of sound to you get?

If it is a continuous sound that means your battery is low. If there are a few beeps every 30 seconds it means that your UPS is being used.

[Anemone]

Have an APC RS 1500, which I'm fairly certain is a simulated sine wave (if it wasn't ungodly expensive it's probably a simulated sine) and a PCPC Silencer 750 and no issues to report.

[ksipsi]

What kind of sound to you get?

If it is a continuous sound that means your battery is low. If there are a few beeps every 30 seconds it means that your UPS is being used.

The sound doesn't come from the UPS but from the PSU itself.

[xytrius]

Sorry, I should have understood your post better.

The noise should be either the fan (very common) or the coils (low noise and less common) or both. The coils make a humming sort of noise and do so under heavy load.

If the noise started after you connected to your new UPS, I regret to say that I do not know enough to tell you what causes the noise.

[xenolith]

OK i connected the UPS to my computer and everything went well. No smoke no explosion no burnt hardware at all!
The only thing is that when the UPS is operating on batteries the psu with the Active PFC makes a strange sound but it works though. Is this normal or is the sign of something bad happening ?

This is a line-interactive ups which supplies "off-line" power from your wall outlet as the primary source and only uses the battery as a secondary source in the event of a power sag or blackout.

wall -> AC/DC inverter/converter -> equipment
...................... | ......... ^
...................... v ......... |
battery <- charging ....... |
.. | ............................. |
.. v____discharging______|

Therefore, this UPS's inverter is supplying sine waveform electrical signals from the wall when it's normally running off-line power (which is actually a good sign that these use a high quality inverter). Only when operating off the battery does it output a modified square waveform.

When testing the UPS by pulling its power plug, what you're probably hearing is, is a higher harmonics (or "buzz") caused from the higher frequencies within your PSU when dealing with the square wave output. IMO, the severity of this buzz is subjective, just like fan noise, some people will be more sensitive to it than others.

The only solution I know of to totally avoid this is to get a very expensive "true" online double-conversion UPS (usually designed for servers.)