Question Home light flickering when PC is running on inverter ?

[shubham1122]

Hello everyone
My PC specs are:
asus tuf gaming b550m-e motherboard
ryzen 5 5600g
wd blue m.2 nvme ssd 500gb
corsair vengence 3600mhz 8*2 ram sticks.
asus tuf gaming 550w power supply
deepcool ak400 air cooler.
No discrete graphic card.

When i run my pc when light is coming then it works fine and also all things(home lights etc) run fine in my home. But when electricity goes and i run my pc on inverter then pc run fine but my home light start flickering. The flickering is somewhat less but yet noticable. And when i open any video on youtube then flickering increases in home light for 5-6 seconds. When pc is idle then home light flickers 2-3 times in 15 seconds.
My home inverter is of 1kva and i never faced any issue like this when pc is off.
Is my pc is creating issue and whether i need to get worried on this or i can leave this issue.

EDIT
One thing i forgot to mention is that lights do not flicker on inverter even if i open 2tv, 3 fans and 10 led bulbs. It is only happening when pc is on.

 

[CountMike]

Hello everyone
My PC specs are:
asus tuf gaming b550m-e motherboard
ryzen 5 5600g
wd blue m.2 nvme ssd 500gb
corsair vengence 3600mhz 8*2 ram sticks.
asus tuf gaming 550w power supply
deepcool ak400 air cooler.
No discrete graphic card.

When i run my pc when light is coming then it works fine and also all things(home lights etc) run fine in my home. But when electricity goes and i run my pc on inverter then pc run fine but my home light start flickering. The flickering is somewhat less but yet noticable. And when i open any video on youtube then flickering increases in home light for 5-6 seconds. When pc is idle then home light flickers 2-3 times in 15 seconds.
My home inverter is of 1kva and i never faced any issue like this when pc is off.
Is my pc is creating issue and whether i need to get worried on this or i can leave this issue.

EDIT
One thing i forgot to mention is that lights do not flicker on inverter even if i open 2tv, 3 fans and 10 led bulbs. It is only happening when pc i

1KVA with about 800W (counting typical loss) is obviously not enough to run all at same time and that shows specially when PC is under load and it uses probably 400W, almost half of available power.
PC has PSU that can compensate for some voltage loss. TVs a little and lights none so no wonder that they have problems.
You need either stronger inverter or to cut down on usage of some devices.

 

[shubham1122]

My pc even under full load will not go beyond 160w.
I also tried running only pc and one 9w led bulb on inverter and same flickering happened.

 

[Dragos Manea]

1KVA with about 800W (counting typical loss) is obviously not enough to run all at same time and that shows specially when PC is under load and it uses probably 400W, almost half of available power.
PC has PSU that can compensate for some voltage loss. TVs a little and lights none so no wonder that they have problems.
You need either stronger inverter or to cut down on usage of some devices.

He has only a 5600G, how in the world that would consume 400W without a discrete video card, only a 5600G and a ssd. Read carefully before you post.
Now on the issue it might be something with grounding or with your PSU. Be sure to completly separate the old electric network from the inverter. Devices which are still conected on the old network and in teh same time on the inverter might cause issues.
Do you have the possibility to ask someone to give you a good quality PSU to test it?

 

[CountMike]

He has only a 5600G, how in the world that would consume 400W without a discrete video card, only a 5600G and a ssd. Read carefully before you post.
Now on the issue it might be something with grounding or with your PSU. Be sure to completly separate the old electric network from the inverter. Devices which are still conected on the old network and in teh same time on the inverter might cause issues.
Do you have the possibility to ask someone to give you a good quality PSU to test it?

You should try reading too. he is running everything from that inverter when there's no other power available so no other network to separate.
Power input to PSU is alway higher than it's output due to losses uncured during conversion. Nest rated ones up to 20% in best case and lesser and unrated ones up to 50%.

 

[shubham1122]

He has only a 5600G, how in the world that would consume 400W without a discrete video card, only a 5600G and a ssd. Read carefully before you post.
Now on the issue it might be something with grounding or with your PSU. Be sure to completly separate the old electric network from the inverter. Devices which are still conected on the old network and in teh same time on the inverter might cause issues.
Do you have the possibility to ask someone to give you a good quality PSU to test it?

None of my friends have desktop pc. I tried getting psu from shop for testing purpose but they refused.
Can you suggest me any another way of finding out whether psu is working properly or not.

But i have a doubt that, if it was a psu related issue then when i run my pc on mains electricity then led buld should also flicker but on mains electricity there is absolutely no flickering.

 

[Misgar]

Are your flickering light bulbs:
LED
Compact fluorescent
Fluorescent strip light
Tungsten filament
Quartz halogen

Is the mains output from your inverter:
Pure sine wave
Stepped approximation

https://forums.tomshardware.com/thr...ormal-and-pure-sine-wave-inverter-ups.243144/

From your description of flickering lights, I suspect your inverter is not generating a pure sine wave output, which would probably reduce or eliminate the problem. Some LED bulbs react badly to non sine wave input, especially in the presence of other equipment generating high levels of EMI.

https://en.wikipedia.org/wiki/Electromagnetic_interference

If your inverter generates a quasi sine wave output, the sudden voltage transitions taking place several times during each half cycle, cause problems for your light bulbs which are designed to work on a smoothly changing sine wave supply.

Cheap LED bulbs do not contain enough bulk storage capacitance to cope with large transitions in mains voltage, each time a step transition occurs in the quasi sine wave approximation.

Add to this the Power Factor Correction circuits built into ATX power supplies and the transient nature of charging currents, that only flow during the brief instant when the mains input voltage exceeds the DC voltage on the 400V bulk storage capacitor and you have a perfect recipe for large scale EMI. ATX power supplies are designed for use on true sine wave supplies, not from crude stepped approximation supplies.

Inexpensive stepped sine wave approximation inverters are not recommended for use with professional computer equipment such as servers. If you can afford one, a pure sine wave inverter will be much "kinder" to your desktop PC.If you're really unlucky, a cheap inverter might destroy your ATX PSU.

Most mains powered electronic equipment found in the home features a switched mode power supply capable of running over the continuous voltage range 100V AC to 240V AC (as mentioned on the label). Hence you can use the same laptop PSU in the USA on 110V 60Hz AC and in Europe where the voltage tends to be 220V 50Hz.

Provided the (sine wave) mains supply does not drop too far below 100V RMS AC during brown outs, electronic equipment will continue to work normally.

All bets are off when you use a quasi sine wave approximation inverter with a really "nasty" output full of strong harmonics. It's hardly surprising some equipment reacts badly when operated outside its design parameters from a cheap UPS.

There is nothing wrong with your PSU. What's "wrong" is the non sine wave output of your inverter.

If your lights flicker when running on inverter, try changing the brand or type of bulb. If all else fails, consider a completely separate emergency light source.

 

[shubham1122]

Are your flickering light bulbs:
LED
Compact fluorescent
Fluorescent strip light
Tungsten filament
Quartz halogen

Is the mains output from your inverter:
Pure sine wave
Stepped approximation

https://forums.tomshardware.com/thr...ormal-and-pure-sine-wave-inverter-ups.243144/

From your description of flickering lights, I suspect your inverter is not generating a pure sine wave output, which would probably reduce or eliminate the problem. Some LED bulbs react badly to non sine wave input, especially in the presence of other equipment generating high levels of EMI.

https://en.wikipedia.org/wiki/Electromagnetic_interference

If your inverter generates a quasi sine wave output, the sudden voltage transitions taking place several times during each half cycle, cause problems for your light bulbs which are designed to work on a smoothly changing sine wave supply.

Cheap LED bulbs do not contain enough bulk storage capacitance to cope with large transitions in mains voltage, each time a step transition occurs in the quasi sine wave approximation.

Add to this the Power Factor Correction circuits built into ATX power supplies and the transient nature of charging currents, that only flow during the brief instant when the mains input voltage exceeds the DC voltage on the 400V bulk storage capacitor and you have a perfect recipe for large scale EMI. ATX power supplies are designed for use on true sine wave supplies, not from crude stepped approximation supplies.

Inexpensive stepped sine wave approximation inverters are not recommended for use with professional computer equipment such as servers. If you can afford one, a pure sine wave inverter will be much "kinder" to your desktop PC.If you're really unlucky, a cheap inverter might destroy your ATX PSU.

Most mains powered electronic equipment found in the home features a switched mode power supply capable of running over the continuous voltage range 100V AC to 240V AC (as mentioned on the label). Hence you can use the same laptop PSU in the USA on 110V 60Hz AC and in Europe where the voltage tends to be 220V 50Hz.

Provided the (sine wave) mains supply does not drop too far below 100V RMS AC during brown outs, electronic equipment will continue to work normally.

All bets are off when you use a quasi sine wave approximation inverter with a really "nasty" output full of strong harmonics. It's hardly surprising some equipment reacts badly when operated outside its design parameters from a cheap UPS.

If your lights flicker when running on inverter, try changing the brand or type of bulb. If all else fails, consider a completely separate emergency light source.

my led bulbs are flickering.
I checked my inverter and" true sine wave ups" is written on its body.
I am not much worried about flickering in lights as it dont much disturb me but i only want to confirm whether it will damage my pc or is there any problem that can arise due to this issue in my home equipments, or is my pc is creating this issue.

 

[shubham1122]

Are your flickering light bulbs:
LED
Compact fluorescent
Fluorescent strip light
Tungsten filament
Quartz halogen

Is the mains output from your inverter:
Pure sine wave
Stepped approximation

https://forums.tomshardware.com/thr...ormal-and-pure-sine-wave-inverter-ups.243144/

From your description of flickering lights, I suspect your inverter is not generating a pure sine wave output, which would probably reduce or eliminate the problem. Some LED bulbs react badly to non sine wave input, especially in the presence of other equipment generating high levels of EMI.

https://en.wikipedia.org/wiki/Electromagnetic_interference

If your inverter generates a quasi sine wave output, the sudden voltage transitions taking place several times during each half cycle, cause problems for your light bulbs which are designed to work on a smoothly changing sine wave supply.

Cheap LED bulbs do not contain enough bulk storage capacitance to cope with large transitions in mains voltage, each time a step transition occurs in the quasi sine wave approximation.

Add to this the Power Factor Correction circuits built into ATX power supplies and the transient nature of charging currents, that only flow during the brief instant when the mains input voltage exceeds the DC voltage on the 400V bulk storage capacitor and you have a perfect recipe for large scale EMI. ATX power supplies are designed for use on true sine wave supplies, not from crude stepped approximation supplies.

Inexpensive stepped sine wave approximation inverters are not recommended for use with professional computer equipment such as servers. If you can afford one, a pure sine wave inverter will be much "kinder" to your desktop PC.If you're really unlucky, a cheap inverter might destroy your ATX PSU.

Most mains powered electronic equipment found in the home features a switched mode power supply capable of running over the continuous voltage range 100V AC to 240V AC (as mentioned on the label). Hence you can use the same laptop PSU in the USA on 110V 60Hz AC and in Europe where the voltage tends to be 220V 50Hz.

Provided the (sine wave) mains supply does not drop too far below 100V RMS AC during brown outs, electronic equipment will continue to work normally.

All bets are off when you use a quasi sine wave approximation inverter with a really "nasty" output full of strong harmonics. It's hardly surprising some equipment reacts badly when operated outside its design parameters from a cheap UPS.

There is nothing wrong with your PSU. What's "wrong" is the non sine wave output of your inverter.

If your lights flicker when running on inverter, try changing the brand or type of bulb. If all else fails, consider a completely separate emergency light source.

My light are only flickering when pc is running on inverter. If pc is not running then none of light flicker on inverter

 

[Misgar]

Oh dear. Bang goes my theory you were running on a quasi sine wave inverter. A pure sine wave inverter is much better.

Yes, I already knew the flickering lights only occurred when you were running on inverter power when the mains failed.

It's obvious from your description that when the ATX PSU is under load, the flickering gets worse. This is only to be expected, because Electro Magnetic Interference created by the ATX PSU increases when it draws more current from the inverter.

So the answer to your question "is my computer causing the lights to flicker" is yes, it's conducted mains borne interference from the ATX PSU that's the culprit. Remember though, most LED light bulbs use the cheapest of components in the most basic of designs and are not immune from interference.

I don't think you'll have any serious problems operating the computer on the inverter's sine wave output. Nothing is 100% guaranteed, but if you shut down the computer gracefully before the inverter batteries go flat, you should be OK.

Try a few different bulbs from another manufacturer.

 

[shubham1122]

Oh dear. Bang goes my theory you were running on a quasi sine wave inverter. A pure sine wave inverter is much better.

Yes, I already knew the flickering lights only occurred when you were running on inverter power when the mains failed.

It's obvious from your description that when the ATX PSU is under load, the flickering gets worse. This is only to be expected, because Electro Magnetic Interference created by the ATX PSU increases when it draws more current from the inverter.

So the answer to your question "is my computer causing the lights to flicker" is yes, it's conducted mains borne interference from the ATX PSU that's the culprit. Remember though, most LED light bulbs use the cheapest of components in the most basic of designs and are not immune from interference.

I don't think you'll have any serious problems operating the computer on the inverter's sine wave output. Nothing is 100% guaranteed, but if you shut down the computer gracefully before the inverter batteries go flat, you should be OK.

Try a few different bulbs from another manufacturer.

Firstly Thanks for such a detailed explanation,but i am little confused that whether pure sine wave and true sine wave inverter are same thing.
And i feel relaxed as you told that their should not be any problem in running pc on inverter.
I got this pc( my first pc ever) build last month only and i feel relaxed that none of my components are faulty,as before i thought my psu or some other pc component is damaged or faulty.
Thanks for your help😊😊😊😊

 

[Misgar]

Yes. Pure sine wave and true sine wave are exactly the same thing.

 

[shubham1122]

Yes. Pure sine wave and true sine wave are exactly the same thing.

Thanku very much for helping me out.🙂

 

[shubham1122]

Yes. Pure sine wave and true sine wave are exactly the same thing.

Hi,
A thought came in my mind that as you said that this flickering is happening because of Electro Magnetic Interference of psu then why it is happening on inverter only and not on mains electricity.

 

[DSzymborski]

What's the exact hardware involved here? You can write "true sine wave" on a sandwich, but it won't make it so. We encounter all sorts of fake products, especially when it comes to power issue; if I had a dollar for every time someone here came across a PSU in southeast Asia or India that said "true rated 700W" or something and it turned out to be a garbage 250W PSU, I could buy a mansion made of solid gold.

 

[Misgar]

Good point. The label on the invertercould indeed be making false claims about "true sine wave output". Perhaps we should enquire as to the the manufacturer and model number of the UPS. If it was an APC unit, I'd have some confidence in the label, otherwise, who knows.

If it was my UPS I'd connect one of my oscilloscopes across the output, taking suitable precautions. This is NOT something untrained personnel should attempt. Mains can be LETHAL A 'scope would immediately prove whether or not the UPS was true sine or stepped sine wave approximation.

As for the reason why the lights only flicker when running from UPS, the reason is simple. The two supplies have significantly different impedance and power rating characteristics.

Your local town mains supply is very low impedance and has the capacity to deliver enormous short duration current transients on demand. Many ATX PSUs will pull 50 to 100A for a few milliseconds from the town mains supply at switch on. This initial current spike charges up the 400V bulk storage capacitor in the ATX PSU.

A typical UPS inverter has a far lower peak current capability and will "squash" any demands from connected equipment for high current peaks. Instead of a relatively "clean" short duration spike when an ATX PSU powers up, the "squashed" long duration pulse(s) delivered by an inverter may be rich in additional harmonics creating more EMI.

Switched mode power supplies pull a series of short current spikes from the mains all the time they are running. On a low impedance town mains supply, these spikes will be attenuated to a greaterextent than possible, from the higher impedance current-restricted inverter output. I have no idea what waveform is output from the OPs inverter when running a PC and LED lights together, but it's obviously rich in harmonics and hence the flickering lights. The town mains supply will be much cleaner with a lower impendance and hence the lights won't flicker.

In the USA most electronic equipment bears the UL mark. In Europe it's the CE mark. In theory this means the manufacturer is claiming their equipment meets the relevant Emissions and Immunity (EMC and EMI) regulations. They don't necessarily have to fully test their equipment, but they must provide adequate documentation as evidence of their claim for full compliance. I've spent many hours in large and small anechoic RF test chambers testing product for compliance. A small chamber is shown below.

Unfortunately, many unscrupulous manufacturers just print a UL and CE symbol on their producta and flagrantly ignore all compliance regulations.

If the OPs inverter is not a "pure sine wave" and compliant with EMC and EMI regs, it may be generating a horrible spectrum of frequencies, rich in harmonics. Hence the flashing LED lights,

 

[shubham1122]

Good point. The label on the invertercould indeed be making false claims about "true sine wave output". Perhaps we should enquire as to the the manufacturer and model number of the UPS. If it was an APC unit, I'd have some confidence in the label, otherwise, who knows.

If it was my UPS I'd connect one of my oscilloscopes across the output, taking suitable precautions. This is NOT something untrained personnel should attempt. Mains can be LETHAL A 'scope would immediately prove whether or not the UPS was true sine or stepped sine wave approximation.

As for the reason why the lights only flicker when running from UPS, the reason is simple. The two supplies have significantly different impedance and power rating characteristics.

Your local town mains supply is very low impedance and has the capacity to deliver enormous short duration current transients on demand. Many ATX PSUs will pull 50 to 100A for a few milliseconds from the town mains supply at switch on. This initial current spike charges up the 400V bulk storage capacitor in the ATX PSU.

A typical UPS inverter has a far lower peak current capability and will "squash" any demands from connected equipment for high current peaks. Instead of a relatively "clean" short duration spike when an ATX PSU powers up, the "squashed" long duration pulse(s) delivered by an inverter may be rich in additional harmonics creating more EMI.

Switched mode power supplies pull a series of short current spikes from the mains all the time they are running. On a low impedance town mains supply, these spikes will be attenuated to a greaterextent than possible, from the higher impedance current-restricted inverter output. I have no idea what waveform is output from the OPs inverter when running a PC and LED lights together, but it's obviously rich in harmonics and hence the flickering lights. The town mains supply will be much cleaner with a lower impendance and hence the lights won't flicker.

In the USA most electronic equipment bears the UL mark. In Europe it's the CE mark. In theory this means the manufacturer is claiming their equipment meets the relevant Emissions and Immunity (EMC and EMI) regulations. They don't necessarily have to fully test their equipment, but they must provide adequate documentation as evidence of their claim for full compliance. I've spent many hours in large and small anechoic RF test chambers testing product for compliance. A small chamber is shown below.

Unfortunately, many unscrupulous manufacturers just print a UL and CE symbol on their producta and flagrantly ignore all compliance regulations.

If the OPs inverter is not a "pure sine wave" and compliant with EMC and EMI regs, it may be generating a horrible spectrum of frequencies, rich in harmonics. Hence the flashing LED lights,

Thanks you🙂

 

[shubham1122]

Good point. The label on the invertercould indeed be making false claims about "true sine wave output". Perhaps we should enquire as to the the manufacturer and model number of the UPS. If it was an APC unit, I'd have some confidence in the label, otherwise, who knows.

If it was my UPS I'd connect one of my oscilloscopes across the output, taking suitable precautions. This is NOT something untrained personnel should attempt. Mains can be LETHAL A 'scope would immediately prove whether or not the UPS was true sine or stepped sine wave approximation.

As for the reason why the lights only flicker when running from UPS, the reason is simple. The two supplies have significantly different impedance and power rating characteristics.

Your local town mains supply is very low impedance and has the capacity to deliver enormous short duration current transients on demand. Many ATX PSUs will pull 50 to 100A for a few milliseconds from the town mains supply at switch on. This initial current spike charges up the 400V bulk storage capacitor in the ATX PSU.

A typical UPS inverter has a far lower peak current capability and will "squash" any demands from connected equipment for high current peaks. Instead of a relatively "clean" short duration spike when an ATX PSU powers up, the "squashed" long duration pulse(s) delivered by an inverter may be rich in additional harmonics creating more EMI.

Switched mode power supplies pull a series of short current spikes from the mains all the time they are running. On a low impedance town mains supply, these spikes will be attenuated to a greaterextent than possible, from the higher impedance current-restricted inverter output. I have no idea what waveform is output from the OPs inverter when running a PC and LED lights together, but it's obviously rich in harmonics and hence the flickering lights. The town mains supply will be much cleaner with a lower impendance and hence the lights won't flicker.

In the USA most electronic equipment bears the UL mark. In Europe it's the CE mark. In theory this means the manufacturer is claiming their equipment meets the relevant Emissions and Immunity (EMC and EMI) regulations. They don't necessarily have to fully test their equipment, but they must provide adequate documentation as evidence of their claim for full compliance. I've spent many hours in large and small anechoic RF test chambers testing product for compliance. A small chamber is shown below.

Unfortunately, many unscrupulous manufacturers just print a UL and CE symbol on their producta and flagrantly ignore all compliance regulations.

If the OPs inverter is not a "pure sine wave" and compliant with EMC and EMI regs, it may be generating a horrible spectrum of frequencies, rich in harmonics. Hence the flashing LED lights,

One thing i forgot to mention is that while building pc i accidentally broke bios button on back of motherboard and that broken button is still inside its outer square case/covering. Is there any possibility that it is making light flickering on inverter

 

[amasoun]

Hello everyone
My PC specs are:
asus tuf gaming b550m-e motherboard
ryzen 5 5600g
wd blue m.2 nvme ssd 500gb
corsair vengence 3600mhz 8*2 ram sticks.
asus tuf gaming 550w power supply
deepcool ak400 air cooler.
No discrete graphic card.

When i run my pc when light is coming then it works fine and also all things(home lights etc) run fine in my home. But when electricity goes and i run my pc on inverter then pc run fine but my home light start flickering. The flickering is somewhat less but yet noticable. And when i open any video on youtube then flickering increases in home light for 5-6 seconds. When pc is idle then home light flickers 2-3 times in 15 seconds.
My home inverter is of 1kva and i never faced any issue like this when pc is off.
Is my pc is creating issue and whether i need to get worried on this or i can leave this issue.

EDIT
One thing i forgot to mention is that lights do not flicker on inverter even if i open 2tv, 3 fans and 10 led bulbs. It is only happening when pc is on.

I have same problem. I have an 80+ gold psu, and kill a watt says my pc is taking only 120watts of power. Even if I turn off every other load on home inverter, led light still flicker in the whole house.
These led light Dont flicker when pc is not powered on and more load is attached to inverter than my pc would put.
In India, we don't have ground wires in our homes.
Everything is fine when grid power resumes.