APC Back-UPS Pro 1000 vs. 'regular' APC UPS vs. Cost?

markg2 · 31 Dec 2017

Assuming comparable VA, both lines offer the same downloadable Powerchute software for automatic system shutdown, I'm having trouble understanding why the Back-UPS is so much more expensive than APC's regular UPS.

I think I'm reading that the Back-UPS 1000 offers far more battery powered up time than the regular APC UPS 1000 due to 'more sophisticated' electronics I do not understand?

Also, it seems (un-intuitively, and if I read it correctly) the Back-UPS doesn't have a useful lifespan anywhere near APC's regular UPS.

Can someone provide a little clarity here?

Mark

fireberd · 01 Jan 2018

If I read the specs correctly the Back-UPS 1000 offers voltage regulation that the other does not. More of a "pro" model. Whether the extra features are worth the extra $$ is up to you.

markg2 · 01 Jan 2018

I don't think APC is doing a decent job describing the product. I saw the voltage regulation but 'assumed' that any good UPS will be keeping spikes/surges within acceptable limits. So the broad brush 'v regulation', as far as I'm concerned, isn't anything to write home about. If you check their Smart UPS line, those beauties do some serious v regulation. I know little about electricity but when the spec talks about a pure sine wave I gotta think that those critters are the serious ones.

I keep seeing snippets of text relating to maximizing the usable battery life by (I think) the user being able to prioritize attached equipment and the device not sending power to equipment that isn't calling for it? I thought equipment was either on or off 120v power (hence, heat sinks on heavy duty light dimmers).

What really got me confused (and enough to give up and buy the thing) occurred when I let APC tell me which unit I needed. (for home/small business) I gave the site: 1 desktop, 1 router, 1 hour and the only choice that was 1000 va Back UPS. There were only 2 other choices and they 700 va and below. Interestingly, the price variance wasn't as huge as I had remembered from the last time I purchased a UPS.

fireberd · 01 Jan 2018

It looked to me that the voltage "regulation" was above the usual surge protection. Voltage "regulation" if it works the way "regulators" do means it will maintain a constant output voltage within the + and - parameters of the input AC line voltage.

I used to use Back UPS in my recording studio but I've switched to Cyberpower UPS. At the time I switched the only Back UPS models that supported PFC power supplies (what all PC power supplies in the last 6 or 7 years are) with a "pure sine wave" output when in backup battery mode were very high priced "commercial use" models.

Ranger4 · 01 Jan 2018

There is a lot of talk about pure sine wave output UPSs that I think are probably mostly sales talk. While the mains supply is very rigorously frequency controlled, the voltage can & often does vary greatly with surges & spikes occurring that electrical people call "dirty power".

Because I get frequent power outages here I have very standard UPS to cope with an outage while I shut down the computer. I then start my back up AC generator which certainly does not have pure sine wave output. In fact the voltage varies depending on the load at any given time, which of course influences the speed of the engine & hence if the speed drops the frequency also drops. I use this with a good surge protector & the same UPS without any problems at all.

Computers operate on DC current & generally somewhere around 3-12 volts, so reasonably large fluctuations of the mains input to the PSU only cause small changes in the DC output. Lightning strikes hitting the power line nearby & huge spikes in the mains supply can & do cause major damage, which will not be controlled by sine wave output UPSs or even a good surge protector.

fireberd · 01 Jan 2018

There are "sine wave" UPS systems and there are "modified sine wave" types. Early PFC power supplies will not work on a modified sine wave. Newer PFC supplies seem to be more tolerant and many will work on a modified sine wave.

High power commercial UPS systems are even more complex. I'm a Retired LAN/WAN Network manager and in my computer room with mainframes, servers, routers, etc the UPS system I had always converted DC to a "pure" sine wave. It operated by first converting the AC power to DC voltage. The DC voltage charged a bank of 60 2VDC batteries and was also converted to a pure sine wave AC to power my equipment. This method also isolated the incoming AC power line from the equipment and any noise, glitches voltage variations were never "seen" by the equipment since it was converted to a DC voltage.

Megahertz07 · 02 Jan 2018

Computers PS converts the AC input to DC and filters with a L-C low pass filter. So it doesn't matter if the input is square wave or sine wave or even DC or AC. This is also the case of any device that has a PS that has 100-240V input.

The only big difference is if you have a device with an input transformer as frequency is very important and square waves has high frequency harmonics that generates heat.

A UPS converts AC to DC and charge the battery.
- On a square wave inverter, the DC voltage is switched directly onto a transformer and the output is a square wave, fixed frequency with voltage variation due to battery voltage.
- On a sine wave inverter, the DC voltage is switched using a high frequency PWM (Pulse Wide Modulation) onto a ferrite transformer, the output is filtered on a tuned L-C filter, and the output is a sine wave, fixed frequency with no voltage variation due to battery voltage.

I see no technical reasons to use a square wave inverter as the PWM circuits are very common and the high frequency ferrite transformer doesn't cost much more than the traditional transformer.

fireberd · 02 Jan 2018

A non "pure sine wave" UPS will power an Active PFC type power supply, however the problem comes in when the UPS switches from the AC power line to battery backup. Most Active PFC power supplies will not tolerate the switch and shut down instead of remaining on. This was a major issue on the Dell forum about 6 years ago when the Active PFC power supply was a requirement for new PC's sold in Europe and there were only a few expensive UPS systems with "true sine wave".

Megahertz07 · 02 Jan 2018

PFC (Power Factor Correction) uses a tuned (60 or 50Hz) input capacitor. This capacitor will fry with the harmonics of a square wave.

markg2 · 02 Jan 2018

Btw, one of our machines is not connected to the UPS with the (time of purchase) supplied data cord for Parachute to operate. Anyone know where to get one or two w/o paying a king's ransom?