I got an email from silverstoneteck regarding the type of UPS to use with my Silverstone ST55F-G PFC power supply I am copying that email with some other emails from Silverstoneteck engineer in Taiwan from the jonnyguru forum thread and pasting them here.There is also a bit of conversation comming in with the emails but I think that will better explain the emails. I am also posting the conclusion explanation excluding my email of all the emails from the same thread. I think that should make up for the factual references. I am also posting a link to the thread again -
http://www.jonnyguru.com/forums/showthread.php?t=3964First one is to me
Support <[email protected]>
Aug 4 (2 days ago)
to me
Dear Sir
Thank you very much for purchasing SilverStone.
Sorry that we didn’t have UPS product that we
could only suggest you choose the UPS which is
“on-line” and “sine wave” output. That will have
higher compatibility with computer power supply"It is fine if you living in US and used 120V input in your OP700, even by a not pure sineware UPS."
This is of course good news for those of us in the US. This is direct confirmation from Silverstone that if you're in a country that uses a 120V standard, you CAN use non sine wave UPSs without damaging their power supplies. This is the "bottom line" answer that I was looking for.
He then addressed the question I had asked about the "buzzing" I hear from the power supply when the UPS is on battery:
"And that sounds you heard from OP700 when you cut the wall power to the UPS is only appear in switch AC input power.
That is PSU primary bulk capacitor recharge, it is no problem.
If that sounds is appear continue, please stop used your OP700 and contact us."I'm a bit unclear exactly what he's saying here. On one hand he said it's no problem, but he also said that the sound is from the capacitor charging, which I would "think" would imply that it would be a momentary sound rather than a constant buzz that only stopped when the UPS switched back to wall power. When he says that the sound should not "continue," is he saying that the buzzing should not continue after the unit has switched back to wall power, or does he mean that the sound should only happen briefly even when on battery, and that it should NEVER be constant? I'd be curious to hear feedback on this from the users here that understand the technical aspects of this.
He went on to say:
"It is so difficulties to clear this responsibility between UPS and PSU of UPS not support sineware outputs will damage PSU when input 240V.
Even a UPS mainstream company like APC, that products will not all support sineware.
Anyway, there is not chance to solve this issue by PSU due to too many components must be upgrade.
But UPS just need to extend PWM duty cycle that top voltage of square wave can be reduced under 400V.
It is easiest way to resolve this issue."
If I'm reading this correctly, he's saying that this issue is only a problem in a 240V system, but that it's difficult to address in the power supply, and that it's easier to address this issue in the UPS.
Thanks again for the feedback here,
A couple more followups from Silverstone Taiwan:
"it is for all PSU will “buzzing” not unique to your OP700.
Actually, only my technical angel, it is fine but no good to use for any PSU with a non sine ware UPS.
If any PSU normality input a non sine ware (when you usually cut the wall power to the UPS),
Maybe it will effect that PSU life."
I have no idea what "technical angel" means (obviously a translation anomaly) but this statement seemed to contradict the previous response saying that using a non sine wave UPS was "fine" in the US. I asked for further clarification and received this response:
"1) If your PSU input voltage = 120V is FINE to work, if your PSU input voltage = 230V will damage PSU IMMEDIATELY.
2) PSU is not design for NON sineware input, it is not health.
Just like smoke is not health for people, but if smoking, people will NOT dead IMMEDIATELY.
If your city isn’t power cut every day and every hours, that damage for you is very small.
3) This is the same situation for all of PSU even not SilverStone."
So... the bottom line appears to be that non sine wave power is technically not good for PSU's, but that taken in moderation, it should not be "that" bad of a problem, and that in general it's fine to use a non sine wave UPS as long as it's in a 120V environment. It also appears that he is saying that this is an issue for ALL power supplies, not just Active PFC power supplies, which is interesting given that this entire line of questioning was originally specific to Active PFS power supplies.
Is this how other people interpret these responses? I'm still very interested in hearing other opinions on this information.
A few more followups/confirmations from Silverstone:
1) Does your information apply to just "Active PFC" PSUs, or to ALL PSUs, including those WITHOUT Active PFC circuits.
Answer:
Both Active PFC and NON Active PFC have this issue.
2) Would it be okay to run the PSU on the battery (non sine wave power) for 20 to 30 minutes in a row every month or two, or is this too much?
Answer:
It is OK, you can believe all of SilverStone products have warranty and we will offer this service.3) My APC unit runs an "Automatic Diagnostic Test" at regular periods which switches the unit to battery power for several seconds. I don't know how often this happens, but if it happens more than once a day is it a problem?
Answer:
No problem.So, to sum up, the Silverstone engineer confirmed that there is nothing specific to Silverstone Active PFC power supplies that makes running them off of non sine wave power a problem. The only problems that exist apply to both Active PFC and NON Active PFC PSUs, and as long as you're on a 120V system, it is not enough of an issue to be concerned about it.
I'm am still a bit unclear about the implications of his answer to #2 above, but I think that this is due to the translation more than anything, and he did specifically say that it's "okay." The bottom line is that Silverstone does NOT make any recommendations against running their PSUs off of non sine wave UPSs.
Originally Posted by Big-G View Post
Is this the crux of the matter for a 240 V , 50 Hz environment ?
1. It is not safe to pair an APFC power supply with a simulated sine Wave UPS , as it would damage the power supply immediately.
2. It is safe to pair a power supply which is not PFC , with a simulated sine wave UPS
The short answer is "no" -- this is not the general conclusion of the thread. There are three important points to keep in mind here.
First, the only confirmed conclusions offered above (i.e. information that was not just theoretical in nature) came from Silverstone, so things could possibly be different with different manufacturers.
Second, according to the Silverstone rep the issue with over-voltage in 240V envirnments actually had nothing to do with Active PFC. The problems described pertained to ANY power supply when using a non-sine wave UPS in a 240V environment.
Lastly, it's not necessarily true that damage would happen "immediately" -- this would depend on the specific power supply.
The conclusion of the information offered by the Silverstone was that regardless of the presence or type of PFC, a non-sine wave UPS should not be used in a 240V environment at ALL. We can't say for sure that this will effect any power supply from any manufacturer, but the Silverstone rep seemed to indicate this.
The bottom line is that if you want to be safe, you should only use true sine wave UPS if you're in a 240V environment. Whether you should use an Active PFC unit appears to be a separate question, and I honestly don't know the answer to this, but from what I've gathered in my research, other than specific Enermax units, you CAN use Active PFC PSUs with non-sine wave UPSs. It's considered a bit "hard" on the PSU, but it should not be damaging for the short periods of time that the UPS is being used.
That's the overal conclusion that I've come to.
Larry
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