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I have all LED lights (tubelights and bulbs) in my house and has been backed up by an inverter (Luminous Eco Volt +1550 with Inverlast 150Ah Tall Tubular Battery).

The issue is when I connect my desktop computer (LG Thinkcenter, Intel Core i5-7400 CPU @3.00GHz, 16GB RAM, 1TB HDD, no CD/DVD drive) and if that is running on Inverter then my room lights starts flickering. Notice, if I am not running my desktop computer, the room lights does not flicker.

Now the inverter handles all the load I try to throw at it otherwise. Having every light and fan on in the house doesn't challenge the inverter. So it's not an issue of the inverter's power capacity.

Initially I thought the issue is because of inverter. On request to Luminous customer care, they have check by changing motherboard of my Inverter, but the issue still remains same. This says issue is not with inverter.

Then I thought it could be an issue with the electrical socket where I am connecting my desktop computer. So I connected to a different electrical socket, the issue still remains same.

Then to further analyze the issue, I thought their could be some issue with wiring in my house. So I connected my desktop computer at my friend's house who also has Luminous Inverter installed. Surprisingly at his house also the lights started flickering as soon as I connected my desktop computer (just a CPU) and running on inverter.

So now I am thinking there could something wrong to my desktop CPU? I am not sure what to test further or isolate the issue.

Any suggestion?

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  • Replace your AC power supply for your PC with a DC power supply. Converting from DC to AC and back to DC is inefficient
    – Dotes
    Commented Aug 29, 2019 at 1:14
  • Did you ever get this working? If so, please give a check-mark to the answer that helped you the most, or write up your own answer explaining what you did to get it fixed and give yourself a check mark. That will help others with this kind of problem know that this has a resolution and is a good place to look for their answer
    – FreeMan
    Commented Jul 28, 2020 at 15:11

2 Answers 2

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Your desktop computer's PSU draws electricity in a more complicated way than something like a light or fan does. Nothing's really working incorrectly... it's just that the inverter and the power supply weren't built for each other. The power supply is sucking power when the inverter doesn't expect it, causing a dip in the voltage; then the inverter up-regulates the voltage to compensate, only now the PSU isn't drawing any power and the voltage goes too high.

Replacing the PSU with one that does "power factor correction" may fix things. (Be careful - manufacturers of cheap PSUs will flat-out lie about whether a PSU does power factor correction, as they lie about other specs. Buy a trusted brand.) Alternatively you can use a voltage regulator, such as this ugly little box, to isolate the weirdnesses of the PSU and the inverter from each other. A good voltage regulator like that one will instantly solve a wide range of power issues. (I swear by the APC Line-R, but other people prefer the Tripp-Lite brand.)

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  • I am already using UPS (APC Back-UPS 600VA) for my desktop computer. It still flickers lights in my room. Commented Aug 28, 2019 at 14:26
  • 2
    A voltage regulator is not a UPS. A normal UPS waits for a blackout/brownout before kicking in, whereas a voltage regulator is always active. It's basically a small secondary inverter.
    – Sneftel
    Commented Aug 28, 2019 at 14:29
  • Can you suggest any model please? Commented Aug 28, 2019 at 14:29
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    "Active power conditioner/filter" is another term you can search for. A UPS and surge protector are passive devices that only activate when they are needed. An active filter is always working to improve the power quality going to attached devices.
    – JPhi1618
    Commented Aug 28, 2019 at 15:21
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    Why do you have a UPS on a battery inverter? They are the same thing. It's completely redundant. It's a "Yo Dawg" joke. It sounds like your project requires a lot more research/thinking, and a lot less "throwing random parts at it to see what works" - especially if cost is a concern. Commented Aug 28, 2019 at 18:33
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Solar or other off-grid power is 10% generation, 80% conservation... And 10% selecting products.

The first thing that concerns me is plain overload. The problem is "every light and fan in the house" is not a scientific unit of measure. I really wish we had something like a Kill-A-Watt to measure each light and fan. We are concerned with both watts and VA. Watts is the part of the sinewave the device actually uses, but VA is the whole sinewave which the power source must generate. The ratio is called "Power Factor".

Bad power factor is how a low wattage device can overload a large inverter.

A big LG tower claims to be 250 watts at 85% in its marketing material, so that would be 285 VA. (I would be happier with the actual numbers on the nameplate). And that is worst-case (max load)/best case (highest power factor at max load), the PF could be notably worse at lower loads. If the PC has been upgraded with an aftermarket power supply, all bets are off - an "850W" power supply actually wants 1200VA.

A competent quality 150AH battery + 1000W inverter combo goes for about $450 in the US market, so your $360ish is sensible given lower Indian distribution costs. Of course, this means nothing at all; the latest trick of the junk sellers is to set prices near quality units. Another plus is that they have a customer support line and do try assembly level repair on the units. However they seem wobbly on the actual capacity of this thing. The "1550" number suggests 1550W yet their own marketing material suggests 950 watts or so. Maybe it's 1550W peak.

I would be happier if you could get a power monitor like a Kill-a-Watt and survey each of your loads. Better would be to put it on the inverter output, and closely watch both VA and watts as you run different loads. 250 watts is a lot of power by comparison to your other devices, so I suspect the PC may be overloading the inverter when combined with the other house loads.

One other thing: don't put a UPS on a UPS. If you are running this battery system to deal with short term utility power failures, then plug the PC's UPS into the mains power, not into the Eco Volt. Let the PC UPS back up the PC, and the Eco Volt back up he rest of the house.

If you are entirely off grid on solar etc., then get rid of the UPS since the Eco-Volt already does that... then remember what I said about solar being 80% conservation. Your PC is too inefficient... select a more efficient one. Mac Mini's from just a few years ago are high water marks for cramming an impressive amount of performance in quite a small energy budget. And their power supplies are quite good on Power Factor. There are many other micro-PCs, and these might be better still if you can get a power supply that runs on 12V directly (no such exists from Apple). However the micro-PCs I have seen are weak tea from a performance PoV and their performance:energy use ratio doesn't match Apple. You can run Mac hardware Windows-only, or Linux only... no need for MacOS.

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