Why is there a power surge when UPS connected to my PC switches to battery mode ?

[vijaykec73]

When UPS switches to battery mode due to power blackout my PC restarts with a message "Asus Anti Surge Protection Triggered Due to unstable PSU". This happens only when I play games or when my GPU is at full load and does not happen when I am doing any normal tasks. My mother board is a Asus M5A78LM/USB3, my PSU is a Corsair VS 550W and 600 VA UPS.

Processor : AMD FX-6300
GFX card : Sapphire R9 270x

Is my UPS under powered ?
Also, have I already damaged my PC due to the surge and restart ?

 

[Blain]

Is my UPS under powered ?

Yes, it's best to protect with a unit that has excess capacity over the rating of your PS.

W & VA aren't measurements for the same rating.

 

[www.am27]

well in your case i think it is the problem with Asus i saw some of them have the problem and i disabled the feature from BIOS.. and now all are working fine so please disable the Anti surge feature.. In most cases it is the software problem i mean the BIOS. Also please check if all your power connection is tight or not if their is a lose connection(inside and outside the cabinet box) please correct it. If the problem persist reply here i will try to solve... Thank you.

 

[vijaykec73]

thanks for ur response. I have checked the connections and they are right in place. Disabling thr feature in BIOS is one of the solutions. I am just afraid about what will happen if there is a real surge. Or its just a useless feature to ignore ???

 

[www.am27]

thanks for ur response. I have checked the connections and they are right in place. Disabling thr feature in BIOS is one of the solutions. I am just afraid about what will happen if there is a real surge. Or its just a useless feature to ignore ???

Just ignore it and if you are afraid about real surge just buy a good surge protector from market or from any online store.. Its not as usefull as you are thinking and as i stated above many users of Asus have this problem and they are running it with disabled. Don't worry about it.

 

[westom]

thanks for ur response. I have checked the connections and they are right in place.

It is reporting a defect that is not (yet) serious enough to cause you problems. Most who make decisions only from observation will assume it is irrelevant because the computer did not crash. Others know that defects may or may not cause problems (or may be extremely intermittent) But that defects and resulting problems do not always coincide.

Power surge can mean too much voltage, too little voltage, too much current, or too little current. Many automatically assume the word surge means a specific thing.

In your case, the most likely reason for a power surge is a power supply somehow designed incorrectly. Or a UPS that does not properly switch fast enough. Either way, your computer is observing a voltage drop that must not exist - either due to a defect in the PSU or UPS. A defect that may become worse with time or even cause failures when the room is hotter or colder (those temperature extremes are normal and good for properly functioning computers).

To say more means you must get and post relevant numbers. Or just keep swapping parts until symptoms disappear.

 

[Azix]

Be careful with regular UPS systems. If its not a pure sine wave UPS you get stepped sine when the battery kicks in. I am convinced this contributed to my constantly dying components in the past.

Nowadays I forego UPS systems altogether and just use a voltage regulator plugged into a surge protector.

 

[Blain]

Be careful with regular UPS systems. If its not a pure sine wave UPS you get stepped sine when the battery kicks in. I am convinced this contributed to my constantly dying components in the past.

How are you convinced of this?
It seems counter to the vast number of modified sine wave UPS out there, that quietly do their job. If it's true that these modified sine wave UPS's have been killing components, wouldn't it have been discovered by now?

 

[Jeff7]

How are you convinced of this?
It seems counter to the vast number of modified sine wave UPS out there, that quietly do their job. If it's true that these modified sine wave UPS's have been killing components, wouldn't it have been discovered by now?

A properly designed switch-mode power supply will indeed handle modified sinewave or squarewave input with no problem.

First thing a power supply does when it takes in power is to rectify it to DC and charge a capacitor before feeding it to the rest of the circuit.

Many are also rated to run on straight DC. (Example: A supply specsheet I have here says: "90-264VAC, 127-370VDC input.")

Cheap ones might have an issue with the rapid turn-on of squarewave AC as opposed to the gentle slope of a regular sine wave. They can skimp on things like the input capacitors, diodes, or just about anything in the unit.
Two power supplies: Cheap generic junk on the left, and an Antec Truepower on the right.
Cheap junk has two 330uF caps. Antec has 820uF. There's also more heatsinking, dedicated filter and a beefy rectifier on the input, chokes on the output, and more filtration and regulation circuitry all around. All that helps to reduce the noise that ends up on the output lines, and the big caps work to filter out glitches in the incoming power feed.

If the OP's power supply has undersized input capacitors, then the switchover time of the UPS might be longer than it can handle. That results in a power glitch on the DC side, and the motherboard complains about it.