AC 240V location.

My computer at home keeps restarting at the time of fluctuations and i loose all my work, this happens minimum once every day and some days more than 2 times.

I have 1100va Microtek Inverter (Microtek ups sebz 1100va) with UPS mode for computers for quicker switching.

still it started to reboot my computer. at the time of fluctuations and low voltage.


Then i have been told i need a stabilizer so recently i bought Microteck EMT2090 Stabilizer (Microtek EMT 2090 Voltage Stabilizer for LED Television (2 Amps) (90V ~ 300V)) and connected it before the Inverter.


But still my computer keeps restarting.

Now i have been told i need double or triple booster Stabilizer.

What i need to do , so that my computer wont restart at the time of low voltage and fluctuations.

More details : My PC runs 24x7

There are low voltage and electrical fluctuations are common in my area. My inverter and external battery(exide tubular battery 180ah) is 1 year old, my stabilizer is new.

My computer has corsair VS450 SMPS and i have calculated computer power usage from https://outervision.com/power-supply-calculator and its not more than 300 watts. so its not like , my computer is drawing more power than the inverter can provide.

i have checked earthing in home and its Good.

i was thinking that my inverter was faulty so i sent it for repair at customer care and they told me, its fine. so issue with my home power supply only.

If i switch power supply of inverter off then inverter comes online and PC doesnt reboot. i have tried doing it many times. switching power supply of inverter off then on continuously , and computer does not restarts.

But once in while at the fluctuations computer reboots.

Why exactly is this happening ?

what i need to make it stop rebooting the computer ?

I can think of 2 ways.

1) buy Triple BOOSTER Stabilizer (Microtek EM4090 Digital Display For AC upto 1.5Ton Voltage Stabilizer (90V-300V) )


2) buy small UPS which gives power backup for 15 minutes and install it like this.


update 1 :

i as suggested to measure the fluctuations , i dont have Battery powered oscilloscope with me.

update 2 :

The UPS operates from Standard Voltage range from 100 V~ 300 V and Narrow Voltage range from 180 V ~ 260 V for running computers and sensitive appliances.

idk how i missed it, but the UPS/Inverter has narrow mode which works in

180 V ~ 260 V

so if input voltage to UPS/Inverter goes below that range then it does not works in narrow mode i guees so , so what i need is power supply cutter when the voltage drops below 180 V or goes above 260 V so it will get my UPS online.

so i have ordered Microtek EM 4170+ Voltage Stabilizer (Microtek EM 4170+ Voltage Stabilizer for A.C. upto 1.5 Ton (170V ~ 270V))

i don't want my stabilizer to double or triple boost voltage, and reach the 180 V ~ 260 V range. so that inverter can work in narrow mode , i just want it to cut power altogether and let the UPS take over, UPS is more than enough to give power backup for 8+ hours.

will update when i receive the new stabilizer and do some tests.

  • A side note for anyone else confused by this: MicroTek does not appear to be in any way related to the networking company MicroTik. – SomeoneSomewhereSupportsMonica Sep 7 '17 at 6:55
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    Can you measure these "fluctuations"? – ThreePhaseEel Sep 7 '17 at 11:32
  • how to measure it ? – user75174 Sep 7 '17 at 12:01
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    I'm voting to close this question as off-topic because questions about computers are off-topic here. – mmathis Sep 7 '17 at 16:48
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    You could always switch to a laptop. :) – mbeckish Sep 7 '17 at 17:05

Not wishing to state the obvious, but really, the first thing to do is resolve the power fluctuations if at all possible.

Assuming that's out of your control, then a decent UPS should be able to handle this by itself. You shouldn't need external inverters or stabilisers.

To be honest, at first glance, it sounds like your initial UPS may be faulty or simply not up to the job. Can you be more specific about the nature of the fluctuations and how long they last?

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  • sometimes 2-3 fluctuations triggers the reboot, and voltage drops to 65 volts rarely. if i manually cut of power supply then computer stays on, so it got to be low voltage and fluctuations at the same time. thanks. power cuts and fluctautions , low voltage are very common. – user75174 Sep 7 '17 at 6:58
  • i have 2 inverter, 1 for home and 1 just for my PC, when i sent my inverter which used for PC to repair, then i connected PC to home inverter and same thing happened and besides the technician also said, its not inverter's fault. i guess, i just need something to cut of power when it goes below the specific range and i dont need any stabilizer as my inverter is capable for providing more than 6 hours of power backup. – user75174 Sep 7 '17 at 7:01
  • If you unplug the inverter while the PC is running, does the PC shut down? If so, you have an issue with the PSU not holding up for the length of time it takes for the inverter to kick in. – SomeoneSomewhereSupportsMonica Sep 7 '17 at 7:04
  • i have tried that many times, pc keeps running. so inverter is good. – user75174 Sep 7 '17 at 7:06
  • Your inverter may be fine, that doesn't mean the electronics that switch the load does works properly in a brownout condition. Buy a better UPS and be done with it. – Tyson Sep 7 '17 at 12:28

Your UPS seems expansive enough that it might have its own logs. See if its AVR kicks in when the fluctuations happened (if you're not there yourself.) Alternative, you seem to have enough money to get a battery powered oscilloscope. My guess is your UPS probably has a subpar or incorrectly calibrated AVR, which probably explains why if effs up on some fluctuations but not on outright outage. I'm guessing it's letting these fluctuations through and or your PC is sensitive enough to those to reboot.

A beefier power supply for your computer might also solve this. Its caps will have more reserve power.

EDIT: Actually, looking at your UPS more closely (I couldn't find an on-line manual for it), it doesn't have a data port and I can't see any indication of AVR-like function. Who knows at what voltage it's pre-configured to switch... Getting a more reputable UPS (with data connection/collection that you can connect to say a laptop, so you can troubleshoot it) would probably be the best way to proceed here.

I would not buy the voltage stabilizer from the same company unless you have a satisfaction/money-back guaranteed right to return it if doesn't solve your problem. It doesn't seem to have much in the way of features either, like data connection or any way to configure anything. Also, a separate stabilizer (with no data connection) has no way to trigger your UPS' to turn on its battery... and itself the stabilizer may not have enough reserve energy to ride the fluctuations.

"Now i have been told i need double or triple booster Stabilizer." Yeah, right... what you need is a UPS from a reputable company with built-in stabilizer (AVR). That means something that's not sold only in India. Have a look at the feature list of a reputable UPS in the power range you need... data connection, adjustable sensitivities, AVR etc. You generally don't need pure sine for a computer.

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  • A beefier power supply, you mean SMPS ? – user75174 Sep 7 '17 at 16:07
  • Yes, replacing your vs405. – Fizz Sep 7 '17 at 16:15
  • VS450, with what do you suggest ? – user75174 Sep 7 '17 at 16:42
  • Fugget about replacing that, your UPS and stabilizer are far more dodgy (upon further investigation). – Fizz Sep 7 '17 at 16:48
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    i have APC UPS with internal battery, it worked great , but its was used to give 15 minutes of power backup. and now its battery is dead, so using this inverter, but i hear you, i need some solid branded UPS which support eternal battery or even with internal battery but with longer power backup. thanks – user75174 Sep 7 '17 at 16:59

Your PC power supply is the issue

The problem is your PC power supply is extremely sensitive to brownouts. That's a bit hard to understand, since most PC power supplies are world voltage 100-240V (dynamically; they buck the voltage down to their working voltage) and your power is normally 220.

A good PC supply should "ride the brownout" down as low as 100V before it has a problem, and then a good one will have enough capacitance to ride through a fraction of a second of blackout. And it's not doing that, because either it's a Cheese piece of junk, or it is worn out (capacitors do age out).

How do we know that? Because you already have a UPS - you have been calling it an inverter. You know it works on a blackout: you have tested it by unplugging it, and it works. Therefore the only possible failure here is that the UPS isn't kicking in, because power is still available, it is just browned out. And the UPS does not see that as a reason to kick in.

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  • sorry but i am confused, you mean SMPS or UPS . thanks – user75174 Sep 7 '17 at 17:23
  • When I say "you already have a UPS" I am rerring to the Microtek Sinewave UPS SEBz 1100 VA. I am relying on that item's claim that it is a UPS with a battery, in the US/English sense of the word "UPS". Can't guess what the British call it lol! – Harper - Reinstate Monica Sep 7 '17 at 17:28