Sinister smoke rising from UPS

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CommuniCat

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I keep on blowing up my UPS after "Ek's Dom" puts the power back on. I don't know if it's me as a bad user or the UPS I have, which may just be rubbish.

First I killed a little 600w ups system (erm, a Made in China model, I'm afraid) this week. The power went off so I connected up a small (also 600w) generator to run a laptop, desktop and screen. The idea of the UPS was to ensure clean power to the computers. Am I wrong in assuming that this is one of the functions of a UPS - to ensure clean power from not so clean sources?

The truth is that the UPS worked just fine and was happy running between the generator and the computers.

Well, it worked fine until the power came back on and I tried to move everything back onto the mains. I switched over in this oder: Switched the generator off, pulled plug out of extension from generator, plugged the UPS into main socket, switch on mains power.

The UPS died somewhere in this prodecure.

Now I figure that since there is nothing in the instruction manual indicating any specific procedure for powering down and powering up the UPS, I'm assuming that it's supposed to work just fine swapping between electricity sources. I thought I had a dud UPS and took it back for a replacment.

The shop owner dutifully replaced the 600w UPS with a 1000w UPS of the same (Made in China) UPS system. I just paid in a bit extra for the upgraded model.

Tonight the power went off and I needed to work so I cranked up the genny again. Plugged in the UPS and ran the machines just fine. When the power came back on I thought that I'd better not switch off the generator first, but rather pull the plug first.

The moment I pulled the plug on the UPS it started makeing a very pissed-off sounding continuous buzzing alarm (not the half-annoyed no incoming power sound). Eager to comply with giving the thing something to feed on, I plugged the UPS into the wall socket and switched it on.

Well, didn't a nice pretty whisp of blue electrical smoke start wafting up from the UPS. I switched the UPS off. The smoked stopped rising. I was about to bring out the marshmallows and a stick . . . but nothing happened after that. I switched it on again 5 minutes later and it seems to be running just fine again.

Next time I need to swap sources I think it may just be better to switch the UPS off first. But again, isn't that half the point of a UPS? It has promsies of voltage protection, surge protection and overload protection written all over the box when in reality it seems to be a relatively sensitive piece of equipment?

Or is it just me, the user, abusing the equipment simply without knowing any better?
 
Sounds like you over loaded it, and it popped. What do you have running on it? Normally if it makes sounds when the power goes off (and right away), its an indication its over loaded.
 
w1z4rd said:
Sounds like you over loaded it, and it popped. What do you have running on it? Normally if it makes sounds when the power goes off (and right away), its an indication its over loaded.
Click to expand...

Thanks w1z4rd

The UPS has two "monitor power" type outlets. The first outlet I have pugged directly into my older, not so energy conscious desktop which runs a very hot running Prescott chip, two HDs, and a 17inch lcd display. It also runs a Thermaltake beetle and about a million RPM to keep the Prescott chip cool. I'm assuming that it's not running more than the power pack can provide though? If so it must max out at about 200w to 250w - I'm pretty sure it's not as high as 300w.

I don't know what the monitor is pulling, but as an LCD I don't think it's too much - 100w tops?

I don't think the laptop is using anything at all. 50w? Lets be generous to the UPS and say 100w.

Worst case I'm using a maximum of 500w to run the whole setup. I know that the 600w generator struggles a bit with the main machine on (altitude?). So it's probably around 450 - 500w.

But that was a 1000w UPS with blue smoke tonight?
 
Are you running printers from the UPS, in fact what exactly are you running from the UPS?
 
The shop owner dutifully replaced the 600w UPS with a 1000w UPS of the same (Made in China) UPS system. I just paid in a bit extra for the upgraded model.
Click to expand...

I have a suspicion that these are actually 600 VA and 1000 VA UPSs. Taking the power factor into consideration they are actually closer to 300 W and 600 W respectively.

Am I wrong in assuming that this is one of the functions of a UPS - to ensure clean power from not so clean sources?
Click to expand...

UPSs basically only offer protection from power dips. They don't do any line conditioning.

Tonight the power went off and I needed to work so I cranked up the genny again. Plugged in the UPS and ran the machines just fine. When the power came back on I thought that I'd better not switch off the generator first, but rather pull the plug first.

The moment I pulled the plug on the UPS it started makeing a very pissed-off sounding continuous buzzing alarm (not the half-annoyed no incoming power sound). Eager to comply with giving the thing something to feed on, I plugged the UPS into the wall socket and switched it on.
Click to expand...

I suspect that this was a surge, 230V from the mains plus whatever was coming from the generator.
 
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fskmh said:
UPSs basically only offer protection from power dips. They don't do any line conditioning.
Click to expand...

That depends on the category, the cheap brands for the most part don't offer any form of conditioning and usually have high VA ratings with low RMS power output figures.

Anyway hooking up ANY high current devices would cause the symptoms you described, laser printers (other printers types too depending on model), high output sound systems, plasma displays (high power up current if I remember correctly) and some CRT's.
 
Gnome said:
That depends on the category, the cheap brands for the most part don't offer any form of conditioning and usually have high VA ratings with low RMS power output figures.
Click to expand...

Well I assumed from the OP that we're not dealing with a R4k sinewave UPS here ;).
 
CommuniCat said:
No printers - just the desktop and laptop as specified above.
Click to expand...

Hmm :( Think the UPS just can't handle the mean power output (as mentioned by fskmh), I have a APC 2000VA unit that cost me around R1.5k around 2000, the batteries quit on me at some point which cost around R90 to replace, it's still going strong ;)

Well worth it! The batteries are very easy and cheap* to replace.

*Ok depending on the model, most of these small UPS's run from 12v 7aH batteries, they cost around R40 a pop from electronics stores such as communica.
 
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fskmh said:
I have a suspicion that these are actually 600 VA and 1000 VA UPSs. Taking the power factor into consideration they are actually closer to 300 W and 600 W respectively.
Click to expand...

I've just looked at the specs again. I think you are quite correct in this.


fskmh said:
UPSs basically only offer protection from power dips. They don't do any line conditioning.
Click to expand...

Okay.


fskmh said:
I suspect that this was a surge, 230V from the mains plus whatever was coming from the generator.
Click to expand...

But the generator was unpugged at the time? Power surge from 230V mains very likely after an Eskom outage though.

I just tested the UPS again now by switching the mains off. The UPS is quite happy with this situation. It runs both the desktop and the laptop and just gives off an alert that there is no power. Switching the mains back on again is also not a problem.

If the system was overloaded, would it not bitch again if the power went off?

I'm thinking that a total system shutdown between main line and generator sources may be a more stable way run this setup though.
 
Gnome said:
Hmm :( Think the UPS just can't handle the mean power output (as mentioned by fskmh), I have a APC 2000VA unit that cost me around R1.5k around 2000, the batteries quit on me at some point which cost around R90 to replace, it's still going strong ;)

Well worth it! The batteries are very easy and cheap* to replace.

*Ok depending on the model, most of these small UPS's run from 12v 7aH batteries, they cost around R40 a pop from electronics stores such as communica.
Click to expand...

Thanks, I'm getting the idea ;)

Buy cheap UPS, get cheap UPS result.

If I'm going to spend money though I'd rather spend quite a lot more and set up a deep cycle battery and 2000w inverter system to power this setup and more if necessary. I'd far rather switch on an inverter than lug generators around.
 
CommuniCat said:
fskmh said:
I suspect that this was a surge, 230V from the mains plus whatever was coming from the generator.
Click to expand...

But the generator was unpugged at the time? Power surge from 230V mains very likely after an Eskom outage though.

I just tested the UPS again now by switching the mains off. The UPS is quite happy with this situation. It runs both the desktop and the laptop and just gives off an alert that there is no power. Switching the mains back on again is also not a problem.
Click to expand...

Oh, sorry, I misunderstood and thought the generator was still on at that point.
 
CommuniCat said:
Thanks, I'm getting the idea ;)

Buy cheap UPS, get cheap UPS result.

If I'm going to spend money though I'd rather spend quite a lot more and set up a deep cycle battery and 2000w inverter system to power this setup and more if necessary. I'd far rather switch on an inverter than lug generators around.
Click to expand...

There's a description of my setup in this thread:
http://mybroadband.co.za/vb/showthread.php?t=112443
 
From first hand experience - ditch the generator.
If it is the 2-stroke unit - it's no good for PC.
One of those killed my APC UPS for that matter.

When you connect the PC the generator takes notable strain.

Checked mine.
No Load - 260V, 54Hz
300W load (PC) - 287V, 45-47Hz

When I contacted the Importer, I was told a PC is large load. I checked mine with a power meter when it was on mains - and had the 300W ready. Took it back and spent my money on a Robin.

Also found an article on the internet where somebody had connected a scope to one of those - looks like a triangular wave instead of sine wave.
The other problem is frequency related - those generators vary too much and the UPS uses the frequency of the source power to determine which frequency it must generate (50 or 60Hz).

The UPS would typically switch on and off erratically and you may even have interference on the screen - my experience if my memory is not failing me on the detail.
 
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dionb said:
Also found an article on the internet where somebody had connected a scope to one of those - looks like a triangular wave instead of sine wave.
Click to expand...

Ouch. You got a linky for that article?
 
Got it..

http://www.jkovach.net/projects/powerquality/

Scroll down to the last 2 pics of Alton generator - typically what you could/may get.
Compare it to the Honda ones there - see what I mean in the earlier post.
Get what you pay for - Honda, line Robin locally use known alternators (Sincro on Robin normally - have seen Honda with them as well)

Note that many vanilla ups's are modified sine wave - a square wave with lower duty cycle. You will see some interesting wave forms from them.
 
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Just a drop in comment, Makro sells Honda generators, they are a bit more expensive but I see they win quite a few awards.
 
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