APC RS1500 won't power new system

[Anonymous user]

Hi

I'm having a problem with a UPS which I would have thought would have worked well with a new system.

It is an APC RS1500 (purchased in 2007) and is rated to 860W and 1500VA. The powerchute software (APC) tells me that the load is about 260W and I can add more devices. However when I perform a self test, the PC dies. It also dies if I pull the plug of the UPS. This is a new gaming system with an OCZ ELITE XSTREAM 800W PS.

I've just tested the UPS with an older smaller PC and the self test and pull the plug test were passed with no problem.

I have contacted OCZ who say that the output from the UPS is not close enough to a sine wave for the PS to work.

Assuming this is correct, I have to say I'm rather annoyed. I paid good money for this UPS and sized it to cope with a new system. Now I find that because of
some rather obscure technical detail, it won't work with modern power supplies.

Is the lack of a sine wave output the problem? What would your suggestions be to resolve this matter?

Regards

Steve Hadcroft

[TheNotoriousKMP_apc]

Steve,

The technical specifications on the APC product page specify whether the output sine wave is pure, or step approximated while on battery.

But if the PS company say it's the sine wave of the UPS that's forcing the system off, then I'd be near 100% positive that's what it is. Also, if it works with another system while on battery, (the UPS that is) then I'd say you've found the problem.

[Anonymous user]

This has me wondering if I purchase the same model as Steve, if I'll have the same problem. I have a high end gaming system with a Seasonic M12 700W PSU, but I'm probably using alot more wattage (4 HDD's, 2 DVD's, Nvidia GTX260 Vid card, etc).

I currently have a Cyberpower 450 watt UPS that I used for my previous system and found out over the weekend that it won't do the job. At the slightest power outage, it just shuts off, while my laptop that's just plugged into the wall is unphased. But I'm wondering if it's because of the same problem as Steve is having, due to the sine wave outpout of the UPS. I was considering upgrading to to an BR1500LCD with enough wattage to do the job, but I'd hate to order a $200 unit and have it not do the job I bought it for.

I've looked on Seasonic's web site, but couldn't find any documentation or support to find out wether I might have problems.

Any ideas?

[BillP]

Hi:

Hadcroft, I tend to agree with you and KMP about that diagnosis. If the power supply does specifically mention that it requires a pure sine wave, then the BackUPS may not be sufficient. A Smart-UPS (besides Smart-UPS SC) will definitely help. Perhaps the SUA750 or the SUA1000, depending on the power requirements of your system.


Warmongerx, it sounds like you were overloading your CyberPower UPS, as you mentioned it is only 450w. It's possible that the BR1500LCD may suit your needs, depending on certain specs of the power supply.

See here our knowledge base specifically relating to use of Back-UPS/ and Smart-UPS SC's with "Power Factor Corrected" power supplies:

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

Thanks

[Anonymous user · Accepted solution]

Most UPSs that plug into the "ordinary outlet" are the standby type. Most are modified square-wave inverter with line-frequency inverter topology. Some are nearly pure sine-wave and there are a few rarer trapezoid wave models.

The basic "engine" design in new UPSs isn't much different from those from 1980s/1990s, but with new models designed around reduced production cost. Many older UPSs are labeled for use with IT equipment only, under the assumption that all IT equipment (back then) are based on non PFC SMPS design.

A rush of problems are surfacing in the last few years as active power factor correction came into common use. I think major PC manufacturers and UPS manufacturers need to talk through the issue.

PC/power supply manufacturers can say the power supply is not designed to accommodate modified square wave.

UPS manufacturers might argue that since modified square wave UPSs are such a common peripheral that has worked fine with SMPS for over two decades, the power supply should be designed to accommodate modified squarewave input.

So... you can use a PSU without PFC...

or use a PFC power supply with a front-end designed to work with sine wave as well as modified square wave input...

or use any PFC power supply with a sine wave UPS.