Connecting UPS units to an inverter, doable?

[ILFE]

I have taken a few days to process some of the information I am learning about setting up my alternate energy system. But, I then began thinking about something that may directly affect the ability of my network to remain online 24 / 7.

Is it okay / safe / feasible to connect UPS units to the voltage inverter, which is powered by batteries? I mean, it sounds pretty crazy, redundant, even to me. Battery voltage to 220vac, to battery voltage to 220vac. The inverter is not a pure sign wave, so I am a bit concerned about it being safe enough for the computers and other electronics. It was purchased at a super deal, so I really didn't want to simply pay the additional monies out for a pure sine wave inverter if I didn't have to.

Incidentally, plugging sensitive electronic equipment into the wall here (Philippines) is not a bright thing to do, considering how unclean the electricity is here, not to mention the spikes, brownouts, etc.

I just want the best way to keep my network up and running 24 / 7, without having to shut it down simply to change power sources.

[Sunking]

Paul what you are talking about is basically done in every data center, telephone office, and any place where critical mission communications is done.

But there are some differences and one of the critical differences is they use very high quality Dual Conversion UPS systems. With that said efficiency and power use of is no concern.

A dual conversion UPS is taking commercial AC power (120/208/277/480 volts) to rectifiers converting it to DC used to charge batteries and then supply a very high quality Pure sine wave inverters.

At the facility service entrance they use a ATS and generator in the event commercial AC power fails. If that happens the batteries are already online to power the inverters if commercial power fails. The generator starts which in turn powers the rectifiers and take over for the batteries.

No the question becomes can this be applied to a solar system. The answer is yes if you can afford it and modify the concept. If you have ever heard of a modified grid tied inverter, that is exactly the same method.

[axis11]

I have taken a few days to process some of the information I am learning about setting up my alternate energy system. But, I then began thinking about something that may directly affect the ability of my network to remain online 24 / 7.

Is it okay / safe / feasible to connect UPS units to the voltage inverter, which is powered by batteries? I mean, it sounds pretty crazy, redundant, even to me. Battery voltage to 220vac, to battery voltage to 220vac. The inverter is not a pure sign wave, so I am a bit concerned about it being safe enough for the computers and other electronics. It was purchased at a super deal, so I really didn't want to simply pay the additional monies out for a pure sine wave inverter if I didn't have to.

Incidentally, plugging sensitive electronic equipment into the wall here (Philippines) is not a bright thing to do, considering how unclean the electricity is here, not to mention the spikes, brownouts, etc.

I just want the best way to keep my network up and running 24 / 7, without having to shut it down simply to change power sources.

Desk top computers wont run on Modified sine wave inverters.

[john p]

AXIS sorry but you are just so wrong. I have never powered them from anything else for the last 10 years and have done other installs same.
I have a 1000 w MSW inverter and 3 "truck "batteries a solar aray 240w and a 25a battery charger and a 30a PWM solar charger.
As in Phils there are just so many "brownouts" (brownouts and blackouts there have same name) I cant trust grid. so opperate from what is basically a big UPS..
there are absolutely NO PROBLEMS opperating desktop computers from MSW inverters..

[russ]

The PC is run off it's own transformer and operates on DC.

[ILFE]

First, thanks to everyone for your replies. As always, great information for a solar newbie.

AXIS sorry but you are just so wrong. I have never powered them from anything else for the last 10 years and have done other installs same.
I have a 1000 w MSW inverter and 3 "truck "batteries a solar aray 240w and a 25a battery charger and a 30a PWM solar charger.
As in Phils there are just so many "brownouts" (brownouts and blackouts there have same name) I cant trust grid. so opperate from what is basically a big UPS..
there are absolutely NO PROBLEMS opperating desktop computers from MSW inverters..

This is good to hear. I guess then, if the inverter is stable enough, I can plug my electronics directly into it, and leave my APC UPS units out of the equation then?

[Sunking]

First, thanks to everyone for your replies. As always, great information for a solar newbie.



This is good to hear. I guess then, if the inverter is stable enough, I can plug my electronics directly into it, and leave my APC UPS units out of the equation then?

Maybe, maybe not. Depends on how many steps are used and the filtering used.

[ILFE]

I took two years of electronics in high school. While I realize this makes me far from a properly educated engineer, I would have thought catching on to this would have been a hell of a lot easier than it is.

I mean, for Pete's sake, I was intelligent enough to become an amateur radio operator. I know my electrical equations, how to wire a home (in the US anyway), and can dial in frequencies on a ham radio! But, I try to sort out what I need for this and feel like an idiot.

[john p]

LIVINGINCEBU.. Think about this.
EVERY cheap consumer UPS has the following components in it
(1) a battery
(2) an automatic changeover switch to go from mains to UPS
(3) a simple underdesigned MSW inverter
And despite all the so called problems of MSW to be used on computers and even some claims that desktop computers wont work on MSW computers ,and other claims they need"filters" etc.. There are millions of computers users that dont know these "problems" and happily using them for many many years now. and most likely for many years to come.
Only data centers and big offices etc use expensive UPS with true sinewave and all the other wonderful things.

And something else not really related there are many so called true sine wave inverters that are not much better than a half reasonable MSW inverter.. and at least in Australia double the price.

[john p]

Any piece of electrical equipment that has survived longer than 6 months on the wonderful Philippines electrical grid with its brownouts, voltage variations from 170 to 220 and all the spikes will survive perfectly on a good MSW inverter..

[ILFE]

Thanks, and it sounds as though you are all too familiar with electricity here. Gotta love livin' in the Philippines.

Well, one way or another, I am going to have this set up so that my network is only going to be down (locally) when I hit the off button.

[axis11]

AXIS sorry but you are just so wrong. I have never powered them from anything else for the last 10 years and have done other installs same.
I have a 1000 w MSW inverter and 3 "truck "batteries a solar aray 240w and a 25a battery charger and a 30a PWM solar charger.
As in Phils there are just so many "brownouts" (brownouts and blackouts there have same name) I cant trust grid. so opperate from what is basically a big UPS..
there are absolutely NO PROBLEMS opperating desktop computers from MSW inverters..

Maybe im the only one having the msw inverter and computer problems.
I tried on the three msw that I have. Two pcs x 1500w and 1x 1000w. Not one can make the computer start. I bought the computer and inverters from saudi arabia. Everything with electricity on my home runs on the msw, except the computer.It runs fine on grid power.
Where do i put the blame, the inverter or the computer?
I just hope nobody else gets hold of the same devices that I have.

[john p]

AXIS if you bought them from Saudi Arabia mabe they should be run on oil??
I think you are unique in that not being able to get them to work together..
Have you ever tried to get the computer to work on a bought UPS ? then turned the mains off so it runs on the UPS power??
every computer power supply I have ever seen or worked with will operate ok on voltages between 100 to 140 for 120v or 160 and 250 for 220-240v and frequency +- 5 of 50 or 60hz.

[axis11]

Nope, these inverters are simply air-cooled. No fancy oil cooling needed.
I have not tried to use any UPS at all. I simply let the computer die when the power is off.
The computer's power supply is same as the inverter ( 60 HZ ). Maybe for UPS application( grid power to battery inverter auto transfer) , my inverters might work. But for initial start-up, I dont know.

[john p]

Axis it was a joke.. when I said run on oil I ment oil from the ground.. as its an oil rich country.