UPS Battery Backup power quality

I know many members here have a lot of money wrapped up in their computers and other electronics. Many of you most likely have your equipment plugged into a UPS for protection from power spikes, brownouts, and power outages.
You always hear that electronics need clean power. Typical utility power is less than 3% THD(Total Harmonic Distortion), which is rated as clean power.

I'm sure a lot of you also use a generator during power outages. I do as well.
I have two UPS units, one is a CyberPower 1500VA AVR, the other is an APC 1500 Back-UPS XS. These are the "Line Interactive type of UPS systems. The typical UPS you will find at your local computer store.

I recently purchased a Fluke Power Analyzer to do some testing and decided to see how clean the power is from my UPS units.
The results were shocking! I think I'm going to be shopping for double conversion pure sinewave UPS units soon.
Here are the results of the output of my UPS units running on battery power.
APC:

CyberPower

I wonder how much of that really matters. I've dealt with high power networking computer room UPS systems but those systems are much different - the one we had converted the incoming 3 phase 240 VAC to DC voltage that kept the batteries charged and then converted the DC voltage back to 480VAC to feed the power transformer for the computer room.

That would be the ideal method but the small "consumer" UPS systems don't work that way. I have an APC Back UPS PRO BR 1350VA UPS for my recording studio desktop and recording audio interface unit. I don't find any audio issues (noise, distortion, spikes, etc.) when using the equipment on "battery".

I run my equipment off a UPS. I have a handful of UPS's in my house. I figured that "has" to be better than the power from the wall, so I never cared to look into it any further. My son ran his rig for well over a year without a UPS and it's still going strong.

I'm Running an APC Back-Ups 1500VA (BN1500M2). My son is running a Cyber Power 1350VA that we got from CostCo. Still gotta pick up a unit for my wife.

Sine wave power is important to certain types of loads, specifically those that are inductive. Like transformer based power supplies and motors. So if you want to run these types of devices on a UPS that would be a consideration to look for a true sine wave converter.

However, virtually all newer electronic devices use a switching power supply to convert incoming AC to device DC, and these types of supplies work very well on a non-sine wave power source. So if you just want to run a PC, monitor, router, switch, NFS, printer, etc off a UPS having a true sine wave converter vs a standard step approximation waveform would be a waste of money. You will pay extra for true sine wave, and it is NOT required to run modern electronics.

So save your money for something useful, like beer.

AK6DN said:

Sine wave power is important to certain types of loads, specifically those that are inductive. Like transformer based power supplies and motors. So if you want to run these types of devices on a UPS that would be a consideration to look for a true sine wave converter.

However, virtually all newer electronic devices use a switching power supply to convert incoming AC to device DC, and these types of supplies work very well on a non-sine wave power source. So if you just want to run a PC, monitor, router, switch, NFS, printer, etc off a UPS having a true sine wave converter vs a standard step approximation waveform would be a waste of money. You will pay extra for true sine wave, and it is NOT required to run modern electronics.
So save your money for something useful, like beer.

UPS converts AC to DC, store energy on a battery and then convert it back to AC.
The DC to AC can result on a square wave (cheap UPS) or a sine wave (expensive UPS).

As mentioned, for a switching power supply, it doesn't matter it the input is square wave or a sine wave as the first step of a switching power supply is to rectify the input, and filter with a capacitor.

Compumind said:

@AK6DN -

All my UPS units do the correct raw AC (dirty) to clean AC Sinewave conversion even without the battery.
APC units, very high end, Double Conversion.

FWIW.

Ok, but I still think you wasted your money on those devices.

They are AC/DC switching power supplies that are feeding a high power oscillator (ie, 120V/1000W at 60Hz).
Then you feed that AC to a second rank of AC/DC switching power supplies.
All you have done is created inefficiency (wasted power since no conversion is 100% efficient) in doing the AC/DC/AC conversion unnecessarily.

The switcher in your UPS is really no different than the switcher in your PC, just a different output setpoint (ie, 24VDC or 48VDC or whatever) vs 12V/5V/3.3V/1.XV outputs in your PC.
AC sinewave power is really only critical if you are using a transformer in the power path; and virtually no switchers do that any more.

What you are doing is not bad, it is just more expensive and basically unnecessary.