UPS low output voltage

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VivRose

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My UPS is showing 238v input but only 206v output.

Could this be the reason I've been experiencing a "bogged down" situation on my desktop?

My system is incredibly slow at the moment.
 
VivRose said:
My UPS is showing 238v input but only 206v output.

Could this be the reason I've been experiencing a "bogged down" situation on my desktop?

My system is incredibly slow at the moment.
Click to expand...

No, but it is bad for your PSU to constantly run at such a low voltage, the UPS was designed for 220v but we use 230v in SA.

I had a Powercom Black Knight Pro that did the same, it even indicated on the UPS that it is 220v, but they sell it here in SA.

Proper UPS like APC sell 230V UPS that will not do that.

You get the quality you pay for ;)
 
isnt a ups sepose to run off a relay that sets input volage directly to output?and if mains fall away will switch over to inverted dc
opend a 2000va one and cant use it as a inverter bcs needs mains to enegize relay to start the inverting cycle
 
If I'm not mistaken, your PC/laptop should be fine as long as it gets an input voltage between like 60-230V @ 50-60Hz, unless it's still using a very old PSU that uses traditional transformers and not a switching mode kind of power supply.
 
Pada said:
If I'm not mistaken, your PC/laptop should be fine as long as it gets an input voltage between like 60-230V @ 50-60Hz, unless it's still using a very old PSU that uses traditional transformers and not a switching mode kind of power supply.
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Not entirely true. The PSU should usually work for 100-240volt but it is most efficient @ 110VAC, 220VAC, 230VAC & 240VAC. Any other voltages and the efficiency drops which means the PSU runs hotter which isn't good for it.

Most PSUs don't deal well with under volting as they aren't designed to deal with it. Some review sites do test under/overvolting and even great PSUs don't deal well with it.

The reason is the PSU has a transformer that steps down the voltage, always steps down in ratios eg 20: 1, so regardless of input voltage it will be divided by 20. Even thought the switch mode circuit can deal with a relatively wide voltage range it works best when the voltage is in a very narrow range. The further you stray, the more the switch mode circuit needs to buck or boost which drops efficiency.
 
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Most modern PSUs can run off anything between 100 and 260V without a problem, without changing anything and will give the same outputs, so I don't think it will have any effect on your performance. Most inverters output a square wave, and most multimeters are not true RMS, so if you measure a square wave AC voltage on a meter calibrated only for sine waves, you will get an inaccurate measurement.
 
P924 said:
Most modern PSUs can run off anything between 100 and 260V without a problem, without changing anything and will give the same outputs
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Well coming from someone who understands regulator design I can tell you with 100% confidence that is not true. It can do it, but efficiency drops when you stray from the ideal range.

Few desktop units are ever tested beyond the standard ranges (110VAC @ 60hz, 220,230,240VAC @ 50hz) and fewer are actually designed to support those ranges efficiently.

Confusing it can be done with it is a good idea is a big mistake IMHO.
 
Gnome, don't know exactly where you get your figures from, but most PSUs will be more efficient the higher the voltage.

(as somebody that has designed switch-mode PSUs)
 
P924 said:
Gnome, don't know exactly where you get your figures from, but most PSUs will be more efficient the higher the voltage.

(as somebody that has designed switch-mode PSUs)
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And the UPS is dropping the voltage, so naturally the efficiency decreases.

Also frequency plays a role. It really isn't that simple. And I disagree with the higher the voltage the more efficient, that is not always the case.

SMPS design is incredible complex, it isn't as simple as higher voltage = higher efficiency. If you made that suggestion to any engineer they would laugh at you.
 
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Update.

I connected the CPU directly to the mains power and left the flat screen on the UPS.
Powered up the system and left it to run overnight.

This morning the UPS on screen monitor showed input and output voltage as 236v and a 5% load.

The PC is definitely more responsive so I'm not going to re-connect it to the UPS. The frequent internet explorer crashes seem to be a thing of the past.

But like the experts say; "One swallow doesn't mean it's spring". I'll wait and see.

I do believe that it's time to replace the UPS since its 4 years old, which is about the limit for lead acid batteries.
 
It is impossible for a UPS to make your computer slower.

Replacing it won't solve the problem, not unless you buy a higher quality UPS.

The voltage in SA is between 230-240v, usually at peak times it is 240v and that is when a cheap UPS will step the voltage down.

It has absolutely nothing to do with the UPS but the fact that peak times the voltage is increased by Eskom, probably to reduce the transportation losses on their network (lower voltage = more current = more power lost as heat in wires).
 
Solution.

Firstly thank you everyone for the input above.

I was concerned about the CPU receiving low input voltage of 206v over a long period. I'm certainly not qualified to answer the question myself hence my posting on this forum.

The computer is back to it's old tricks so my short lived elation is now dampened. Possibly the brief improvement was a result of re-booting.

I am going to replace the computer, and this time round not a Fujitsu - Siemens from Makro.
 
VivRose said:
Update.

I connected the CPU directly to the mains power and left the flat screen on the UPS.
Powered up the system and left it to run overnight.

This morning the UPS on screen monitor showed input and output voltage as 236v and a 5% load.

The PC is definitely more responsive so I'm not going to re-connect it to the UPS. The frequent internet explorer crashes seem to be a thing of the past.

But like the experts say; "One swallow doesn't mean it's spring". I'll wait and see.

I do believe that it's time to replace the UPS since its 4 years old, which is about the limit for lead acid batteries.
Click to expand...

Look at your PC's power settings. Set them to high performance.

As far as batteries are concerned, yes they should be looked at, but only if they affect your autonomy. To test this, connect cpu & monitor to UPS and switch the mains plug off. If the machine dies immediately then you battery needs replacing. If it runs for the expected time, you can wait.

Internet crashes are not affected by the power source to the PC. The power source to the modem, possibly, but unlikely.

It's more likely that your dns is screwed, so first thing clear your dns cache. A coule of ways to do this:

1. Run ipconfig /flushdns fro a cmd line prompt.
2. rclick your network icon ann run repair.
 
Maybe you just need a format & reinstall of windows.

You could always test the machine with a linux livecd to see if it has issues.
 
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