I just mindlessly bought 650VA EasyUPS and 1500watt generator

[Anonymous user]

Here goes.. So I'm now stationed to work from home and I cant afford to go offline when power goes out. Without researching and just relying on the salesman, I went out to buy 1 UPS and 1 generator only to find out that they don't work together! I'm confused why. UPS still beeps when already plugged on generator power. This article say that I need generator size of x3-5 times of total load attached to it. My PC and modem just consume approx 400watts. Multiply by 3=1200watts. Does this mean I need a generator that outputs 2000w?

Also, after hours of researching online, It seems that I bought a Line Interactive type of UPS. If I replace this with a Online double-conversion type, would it fix my problem? Because maybe my generator outputs dirty power? And I wouldn't worry about generator size and such?

By the way: Only PC, modem, led light, and maybe a fan is using the generator. Thank you guys. Sorry bad english.

Edit: It seems that there's no way to know if a UPS is an Online double-conversion type in APC. Is there an equivalent type of UPS in APC?

[robmir_apc]

New double conversion are way more expensive and it's what you should bought at first. Look at the SRT series or perhaps search for a used or refurbished with warranty and I guess a 1500 Watt generator is more close to the short side, perhaps will force your UPS to depend more on the batteries and short their  life !!!!

[sbagdon]

What type of generator did you buy... if not an inverter-generator, your power might not be clean enough for the UPS, and the UPS thinks that you have under/over or dirty voltage, and is trying to "fix" the problem. I can't imagine a non-inverter 1500w generator producing anything close to "clean" power. Now I'm curious... we have both inverter and non-inverter generators in that size, here... should try plugging one of our 1500va UPS's up to each...

[Anonymous user]

I'm torn. I'm afraid an SRT series would not work too because I just found out that my generator a non-inverter type and produces "dirty" power. On top of that, I'm now scared my PC will blow up because of this generator haha. Can a SRT UPS work with this generator?

[robmir_apc]

I did a little Google search and found a old post from someone  with the same situation, the reply from people trying to help him so I will quote it and after this quote I will post the funny reply from the person with the problem: 

Quote:

Off-line and line-interactive UPS technology

An off-line (including line-interactive) UPS passes mains power to the critical load. An off-line UPS may have some surge suppression and filtering, but will have no power conditioning. A line-interactive UPS will have some power conditioning functions, but will focus entirely on correcting voltage variations by means of a transformer and an automatic tap-switching feature. This has no effect on frequency variations, so the line-interactive UPS reacts to out-of-spec frequencies the same way as the off-line UPS, i.e. it will transfer to battery. When the battery is depleted, the off-line or line-interactive UPS will shut down the critical load.
Why on-line UPS technology works best with generators

On-line or double conversion UPS designs are ideal for use with generators because they accept input power with relatively wide variations in voltage and frequency. An on-line UPS actually re-develops the waveform. The AC input from either the mains or a standby generator is first converted to DC by the rectifier. The DC current is used to charge the battery. During an outage, DC current from the batteries is reformed by an inverter back to perfect sine-wave AC for the critical load. Newer models also use power factor correction to provide an even wider input voltage range.

Because of this double conversion (AC to DC, then DC to AC), variations in the input frequency are of little concern. Therefore the same frequency variations that would cause an off-line or a line-interactive UPS to transfer to battery power have no effect on the on-line UPS.

Quote from the one with the problem:

Thanks. Actual solution = a better generator, but that might be like $8000, so (maybe) a new UPS is more practical.

Now since all the SRT series have in the rear a socket to plug external battery packs if you replace your UPS with this series and find that the internal  battery doesn't give you enough reserve time you could add a external battery pack as I did with my main SMX UPS which is not double conversion  but for my purpose does it's job fine with 2 external battery packs which is enough to keep my server, modem, router and access points operative for several hours in case there is a power down ( which occurs at least twice a month ) since I am operating my UPS at no more than 15% of it's load rating. 

[sbagdon]

we smoke meat (ok, that's the biggest tangent ever...!!!), and we have a saying... it's easy to make a fire... it's an art to make a small fire (warm smoke., not hot smoke..)..

It really is a challenge to find/make clean low-wattage... <3k watts, or so. Something has to clean up the current, whether it's the creation (generator) or consumption (ups). The "easy" solution appears to be an inverter-generator... nice clean power. The bigger-solution is a double-inversion UPS... no matter what "crap" power you send it, it'll invert to 12/24/48/96/192v,dc then re-invert to nice clean 120vac (etc).

As it appears you're dealing with a small deployment the solution might not be on the UPS side, it might be on the generation side... acquire an inverter generator? Yet if you were in the 5/6/8/10kva area, it might be the opposite.. find a quality double-inversion UPS, and throw whatever "crap" a/c is available...

Yet either way, it appears you need to clean up your power, either on the generator portion, or the UPS portion.

[robmir_apc]

Unfortunately I have to be the bad guy and provide you with a reality check:

Generators because they are powered by a gas or petrol  motor they have a limited lifespan so sooner or later you will have to replace them but a UPS can stand for many years and in proportion the batteries are cheap to replace.

Look for a SRT series perhaps used on eBay or refurbished from a seller which give you a warranty and take your time for a replacement generator.  

[sbagdon · Accepted solution]

>Generators because they are powered by a gas or petrol  motor they have a limited lifespan so sooner or later you will have to replace them

Ummm... yes, and no. There are quality/no-quality generators, and there are quality/no-quality UPSs... we have a data-center-quality 220vac 196vdc 5000va double-inversion UPS... and we have a POS 650va 525w desktop UPS. And we have a POS 1000w inverter-generator, that's a disaster waiting to happen... and a 5000w continuous-duty NG gen-set, that will run (with proper pm) until the fuel runs out... which is... never.

The OP sounds that he needs 400w of quality AC power... making small power is not easy, as ironic as that sounds... we'd say go find a Honda EB2000 (note the "EB"), and maintain it properly... and we could speak of solar/hydro, inverters/chargers, and battery chemistry... yet here we are, as this is the APC forum. 😉