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Square wave/sine wave output

APC UPS for Home and Office Forum

Schneider Electric support forum for our APC offers including Home Office UPS, Surge Protectors, UTS, software and services and associated products designed to share knowledge, installation, and configuration.

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Javalin_apc
Crewman
Crewman
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23
1387

Square wave/sine wave output

This was originally posted on APC forums on 6/25/2007


My UPS: Back-UPS XS 1500 (865w)
My Computer: Fairly high end gaming system

Question#1: Is the output of this ups to my computer during normal operation a square wave or true sine wave?

Question#2: What is the effect of all the separate "power corrections" in my system components:
1. The ups itself
2. The PC&Power Cooling 850w Pwr supply in the computer
3. The 6 phase power correction circutry on the EVGA 680i mother board


Accepted Solutions
Sgt._Slaughter_apc
Lt. Commander
Lt. Commander
0 Likes
0
1387

Re: Square wave/sine wave output

This was originally posted on APC forums on 6/25/2007


Hello,

The UPS will output whatever it is receiving from the input AC while it is in the online state. When the UPS is on battery, it will output a step-approximated sine wave. More sensitive power supplies cannot run off of the step-approximated sine wave and could potentially drop the load on a power outage. With Power Factor Corrected power supplies, we recommend using a Smart-UPS.

Thanks.

See Answer In Context

23 Replies 23
Javalin_apc
Crewman
Crewman
0 Likes
0
1387

Square wave/sine wave output

This was originally posted on APC forums on 6/25/2007


My UPS: Back-UPS XS 1500 (865w)
My Computer: Fairly high end gaming system

Question#1: Is the output of this ups to my computer during normal operation a square wave or true sine wave?

Question#2: What is the effect of all the separate "power corrections" in my system components:
1. The ups itself
2. The PC&Power Cooling 850w Pwr supply in the computer
3. The 6 phase power correction circutry on the EVGA 680i mother board

Sgt._Slaughter_apc
Lt. Commander
Lt. Commander
0 Likes
0
1388

Re: Square wave/sine wave output

This was originally posted on APC forums on 6/25/2007


Hello,

The UPS will output whatever it is receiving from the input AC while it is in the online state. When the UPS is on battery, it will output a step-approximated sine wave. More sensitive power supplies cannot run off of the step-approximated sine wave and could potentially drop the load on a power outage. With Power Factor Corrected power supplies, we recommend using a Smart-UPS.

Thanks.

Javalin_apc
Crewman
Crewman
0 Likes
0
1387

Re: Square wave/sine wave output

This was originally posted on APC forums on 6/26/2007


Ok, so far so good.
I should have stated that my psu is a PC Power&Cooling 850w unit. I believe the power factor is .98 or .99;
Am I using the wrong ups ? You said I should be using a Smart-UPS.I already paid a lot for the unit I have now!
What to do?

Javalin

Sgt._Slaughter_apc
Lt. Commander
Lt. Commander
0 Likes
0
1387

Re: Square wave/sine wave output

This was originally posted on APC forums on 6/26/2007


The BX1500 runs with a power factor of about .6. Also, you're power supply is 850 Watts, where the UPS can handle about 900 Watts total. You are risking overloading the UPS with your Power Factor Corrected power supply. Have you tried the load on this UPS yet? Power Supplies rarely run at full capacity, and there could be a chance that the UPS will support the load. You may want to put the load on the UPS and just pull the AC power cord to simulate a power outage. If the UPS cannot handle the load, it is because of the step wave and the power factor correction.

You could trade the BX1500 in and receive a discount on a Smart-UPS model through our Trade-UPS program. The link for the program can be found through the following link:

http://www.apc.com/buy/index.cfm

KVAr_apc
Captain
Captain
0 Likes
0
1387

Re: Square wave/sine wave output

This was originally posted on APC forums on 7/13/2007


Most UPS, including your UPS, simply passes on whatever comes into the power line. There are "on line" double-conversion UPSs that constantly passes power through the inverter without any switchover delay and provides a clean output within 3% or so such as the Liebert brand. These are rare and unnecessary under normal conditions.

Sometimes active PFC equipped power supplies interect poorly with quasi-square wave input and cause the UPS to trip out or crash/reboot or shut off your computer. As Sgt Slaughter suggested, you can test this out by pulling the plug. Your power supply can pull around 1,000w input at FULL LOAD, but I'd be surprised if it's pulling much more than 400-500W from the plug even under heavy use and quickly drop to 150-300W once you stop CPU/graphics intensive activity.

If they don't get along, you can change the PSU to a non PFC type or get a SmartUPS, but I wouldn't use APC's TradeUPS program, because in the end it's horribly expensive. A used 1000VA/670W with new batteries is around $120 + S&H and it's just as good as new. You can get a used one from UPSforless.com, or find a dead SmartUPS 1000 to 1500 locally and get a new battery pack from gruberpower.com (or whoever you chose, but BatteriesPlus is a big rip off when it comes to batteries).

Javalin_apc
Crewman
Crewman
0 Likes
0
1387

Re: Square wave/sine wave output

This was originally posted on APC forums on 7/13/2007


Thanks for the reply...
Ok, I pulled the plug on the APC ups and went on battery back-up.
I closed my running programs..Eudora for E-mail and the web browser.
Everything seemed to be ok and then I shut down the computer and replugged
the ups back in and booted up fine so it looks like everything works as it should. I didn't have much of a
load on the computer and didn't run it long on battery.

So I guess I'm good to go and do not need a "Smart-UPS"..yeah.

BTW...My APC 1500 ups is a SX model but I can't find that on the APC web site. Stg. Slaughter refers
it as a BX model ??????

Syn_apc
Ensign
Ensign
0 Likes
0
1387

Re: Square wave/sine wave output

This was originally posted on APC forums on 8/9/2007


Yeah, well at that rate, again, I wouldnt be able to tell you if the unit would actually damage anything. However it sounds like you should really be going for a true sine wave output unit. Also make sure the PSU itself is dust clear and the fans are working properly.

If the PSU is working harder to keep up with a step aprox, and theres allot of dust and sediment on there it could be allowing voltage to cross paths on its boards. A friend of mine had this issue and it eventually fried his PSU because he just never cleaned it, and it got clogged up, passed voltage and super heated the ICs on the board (dust is a huge heat trap).

Just some things to keep in mind.

-Syn

dillinger_apc
Cadet
0 Likes
0
1387

Re: Square wave/sine wave output

This was originally posted on APC forums on 8/8/2007


couldnt help but notice the discussion going on about stepped wave issues with active PFC power supplies... I have a Antec true power trio 650 watt power supply with Active PFC and 3-12 volt rails and using a APC BackUPS XS 500 from what I understand the XS 500 has stepped wave output and was wondering if this would cause any damage to my PC or the components... when running on battery I notice a buzz emitted from my antec power supply, the system appears to run normally and doesnt trip out and shut down. I hope this buzzing sound isnt a warning that my PC will become toast if I leave it setup like this. I looked into the smartups units but thats wayyyyyyy out of my price range. is it absolutely critical to have a true sine wave UPS on a Active PFC power supply?... and also I have some network equipment running on the BX 1500 would that potentially damage my network equipment to? please respond ASAP

thanks
-Phil

Syn_apc
Ensign
Ensign
0 Likes
0
1387

Re: Square wave/sine wave output

This was originally posted on APC forums on 8/8/2007


Im not going to be able to say if it will damage your PSU or not, but I know personally my last PSU was an antec truepower 650w and after time it emitted a buzzing noise and ended up blowing my mb.

How loud is the buzzing? Do you use any monitoring software to see your rail volts at runtime? Are there any power fluctuations or odd happenings?

-Syn

dillinger_apc
Cadet
0 Likes
0
1388

Re: Square wave/sine wave output

This was originally posted on APC forums on 8/8/2007


Havent found any good software that will give me a proper reading of the voltages... but the buzz is louder then the fans. was ur antec PSU making that noise constantly or only when running off battery?

Syn_apc
Ensign
Ensign
0 Likes
0
1388

Re: Square wave/sine wave output

This was originally posted on APC forums on 8/8/2007


at first intermittently, then after time all the time until it was to late 😕

dillinger_apc
Cadet
0 Likes
0
1388

Re: Square wave/sine wave output

This was originally posted on APC forums on 8/9/2007


well my PSU only does it when running off of the UPS, other then that I dont hear it any other time

KVAr_apc
Captain
Captain
0 Likes
0
1388

Re: Square wave/sine wave output

This was originally posted on APC forums on 8/10/2007


The loud buzzing comes from the PSUs front end components. I don't agree with the wording "modified sinewave" because Back-UPSs' output is closer to modified square wave. Although uncommon there is simulated sinewave, which breaks down the climb into several steps.

http://img338.imageshack.us/img338/3759/waveformln6.gif
This is what the output of Back-UPS and majority of "modified sinewave" UPSs look like. In IT loads,this goes through an inductive filter (to keep RFI from power supply from getting into the power line) and turned into ~340v DC. The PSU then converts 340V DC into respective rails through a high frequency converter and an isolation transformer (so you won't have the slightest chance of seeing 340v at the output even in the event of a failure!)

The faster rise and fall jump rather than sloping up/down is causing the inductive filter to make an audible buzz.

Some CRTs and speakers pickup noise and you might see lines or hear the buzzing from the speaker, but that's nothing intolerable for the duration you need the computer to be on UPS. Speakers don't even need to be connected to UPS.

dirtfoot_apc
Lt. Commander
Lt. Commander
0 Likes
0
1388

Re: Square wave/sine wave output

This was originally posted on APC forums on 9/7/2007


Hi DELLsFan,
A Smart-UPS UPS would not accept the square wave power either. It would see it as a problem with incoming AC, and attmept to run on battery to protect your equipment.

DELLsFan_apc
Cadet
0 Likes
0
1388

Re: Square wave/sine wave output

This was originally posted on APC forums on 9/7/2007


Well, that's disheartening. I would pay for a UPS solution that could interpret non-standard incoming power (like square wave, lower frequency, varying voltage) and correct/condition it for sensitive equipment like computers. Surely SOMETHING exists as an alternative to replacing my (relatively) expensive inverters!

KVAr_apc
Captain
Captain
0 Likes
0
1388

Re: Square wave/sine wave output

This was originally posted on APC forums on 9/7/2007


DELLsFan wrote:
Hello!

We own several inverters that we integrated with our solar system at our facilities in Haiti. These inverters produce a square sine wave and not a regular smooth sine wave. Standard UPS systems do not accept square sine wave power. Unfortunately, these inverters were less expensive than the ones that produce the standard smooth waves. As one might expect, we receive fluctuating power from one of three sources at our main facility: City power, Generator power, or solar (usually in the evening). Would a quality SmartUPS from APC protect my sensitive computer equipment at our facilities?

Thanks in advance.
It might work if you get a double-conversion UPS like a Smart-UPS RT, but I don't know how well the front-end can compensate without relying on battery, but it will cost you more than buying a sinewave inverter.

DELLsFan_apc
Cadet
0 Likes
0
1388

Re: Square wave/sine wave output

This was originally posted on APC forums on 9/20/2007


I'm having a difficult time understanding why APC products (which do a fantastic job of doing everything ELSE with incoming power) couldn't accomodate a non-standard sine wave. We can go to the moon and back and deploy an international space station in orbit for years, but can't figure out a way to condition incoming AC power?

KVAr_apc
Captain
Captain
0 Likes
0
1388

Re: Square wave/sine wave output

This was originally posted on APC forums on 9/28/2007


DELLsFan wrote:
I'm having a difficult time understanding why APC products (which do a fantastic job of doing everything ELSE with incoming power) couldn't accomodate a non-standard sine wave. We can go to the moon and back and deploy an international space station in orbit for years, but can't figure out a way to condition incoming AC power?
Standard UPS products are not designed for such. It's possible to design such a thing, but it would not be economically feasible. This is like asking why each and every parking space at Wal-Mart aren't designed to accomodate Hummer H1s.

APC as well as other common UPSs are designed to provide backup protection to IT loads, nominally operating off of the standard grid power.

DELLsFan_apc
Cadet
0 Likes
0
1388

Re: Square wave/sine wave output

This was originally posted on APC forums on 9/28/2007


Thanks for the response. My situation is obviously non-standard. Nothing ventured, nothing gained - so my time here has not been wasted. I am disappointed there isn't a high enough demand for the solution I would require from APC. However, I shouldn't be terribly surprised. After all, we ARE talking about American Power Conversion company - not Haitian Power Conversion.

As for Wal-Mart and the parking lot analogy, just wait a few more years. It's only a matter of time before the US becomes totally dependent on imports & starts buying luxury cars like a Hummer from China. Everything ELSE at Wal-Mart seems to originate from there. When that happens, I'll let you know if your analogy holds. 😉

Cheers!

hayesd601_apc
Cadet
0 Likes
0
1388

Re: Square wave/sine wave output

This was originally posted on APC forums on 3/23/2011


I have come across this non-pure-wave stuff as well. I plan on making an adapter to convert square or modified into pure sine, or at least try to.

Common_Sense_apc
Ensign
Ensign
0 Likes
0
1388

Re: Square wave/sine wave output

This was originally posted on APC forums on 3/24/2011


You're much better off to convert from DC to a pure sinewave....wait....thats what you would have been doing if you invested the money up front for the right equipment

Buy cheap - Buy twice!

svoltmer_apc
Cadet
0 Likes
0
1388

Re: Square wave/sine wave output

This was originally posted on APC forums on 9/19/2011


Earlier you stated that when the APC unit is not running on battery it passes whatever it's source is to the plugged in devices. What does it output when there are spikes or dipps in the input voltage? I ask as we use our APC comming off of a portable generator as a way to clean the power for electronic devices. Also, durring a outage we have used the generator through the APC to power our sump pump and refrigerator/freezers. I have heard that the stepped sinewave is distructive to any motor. Is this the case?

Sgt._Slaughter_apc
Lt. Commander
Lt. Commander
0 Likes
0
1388

Re: Square wave/sine wave output

This was originally posted on APC forums on 7/14/2007


Do you see a small white sticker on the back or bottom of the UPS? This sticker will have the exact model and serial number. Our Back-UPS XS series will have a model number that begins with "BX"

Thanks.