Power fluctuations

[johnashby]

I have a business owner claiming his pc monitors keep flickering and its a non consistent supply of electrix. He doewnt say he trips thr rcd but says this is dangerous as his servers are very important. He uses protection and regulation devices on his equipment. Once I test at the board and at all his sockets and find no issues what would I be looking for next? I believe he is possible seeing in rush voltage due to his IT equipment. I could look at a voltage regulator but other than that or changing his breaker type, I'm not sure what to suggest.
Its not a fault I have seen before.

 

[UNG]

What tests and checks have you done and at what times
Is the fault / problem occurring at regular or random times throughout the day
Is this site on a 3 phase supply

 

[littlespark]

your testers may not pick up instantaneous voltage drops/ spikes.... i think some wholesalers can hire out voltage monitoring devices that can graph voltage against time.

are there any large factories using electric at certain times nearby? Maybe a large machine drawing the power can drop the supply voltage to properties nearby... Filement lamps might show this if they dim for a fraction of a second, but LED types may not.


If his servers are so important... does he not have them on a UPS?

 

[PS Electrics]

your testers may not pick up instantaneous voltage drops/ spikes.... i think some wholesalers can hire out voltage monitoring devices that can graph voltage against time.

Yes this is the next step I would take. You need to build up a picture of what happens over a few days.

are there any large factories using electric at certain times nearby? Maybe a large machine drawing the power can drop the supply voltage to properties nearby... Filement lamps might show this if they dim for a fraction of a second, but LED types may not.


If his servers are so important... does he not have them on a UPS?

I would hope he has the servers on a UPS!

 

[pc1966]

I would hope he has the servers on a UPS!

Sadly "hope" and "expect" are two very different cases!

Not many people apply the resources needed for a high resilience system even though they scream like mad when it goes predictably wrong.

And even of those who have put measures in place, quite a few never really test things out. You know, actually switching off the whole building for 10min or so to see what the situation is when power comes back. Then you find out the hidden IT stuff that was not on UPS, or the server room on UPS/generator backup but the aircon was not so it is now shutting down / failing on overheating, etc.....

 

[KungFuTurkeyLeg]

I've found monitors flicker when using cheap and nasty docking hubs from Amazon. I use a desktop pc and my business partner uses a cheap hub and a laptop. Whenever I plug something into my power strip, his monitors flicker off and then come back on 5-10 seconds later. We're using different plug sockets on the same circuit.

 

[davesparks]

Sadly "hope" and "expect" are two very different cases!

Not many people apply the resources needed for a high resilience system even though they scream like mad when it goes predictably wrong.

And even of those who have put measures in place, quite a few never really test things out. You know, actually switching off the whole building for 10min or so to see what the situation is when power comes back. Then you find out the hidden IT stuff that was not on UPS, or the server room on UPS/generator backup but the aircon was not so it is now shutting down / failing on overheating, etc.....

One of the theatres I work for have UPSs on everything, the server rack, phone system, CCTV, radio repeater, every till at each bar etc etc.
They are tested regularly and well maintained, pretty foolproof.

But despite all this a little while ago the duty technician was called to the bar as one of the tills had gone off. He found the plug for the UPS had been switched off by mistake but the UPS appeared to be completely dead. Very odd but it all came back to life once switched back on.
The bar staff mentioned that there had been a very loud beeping noise which got louder and more regular before suddenly stopping.

So yes the UPS had done it's job perfectly including the alarm going off to alert staff to the problem but as is so often the case the human factor defeated it.

 

[pc1966]

So yes the UPS had done it's job perfectly including the alarm going off to alert staff to the problem but as is so often the case the human factor defeated it.

We had some UPS with external battery packs at one point and they lacked the ability to tell you if the battery isolator was open or closed. Of course one day power went off and UPS died instantly as a result on no battery!

The related MCB tripped / switch off and similar are always a concern, we use the Nagios software system to monitor stuff and email a couple of folks if something goes off/strange state. While it is not a fix, at least you find out quickly that something is up and not in the middle of the night when some overseas customer phones up when it is down for them!

 

[johnashby]

What tests and checks have you done and at what times
Is the fault / problem occurring at regular or random times throughout the day
Is this site on a 3 phase supply

I am only testing in day time hours, Continuity really making sure there are no bad connections.
So more information, there is one circuit in the room and the computer monitor has a battery ups that kicks in when power is lost, I find pointless but its there.
Client uses his expense coffee machine and the monitor goes off but I think it detects a surge ans thinks a power cut is coming. I believe its the coffee machine but the customer was in the same building different room, same set up with no issues.
The other room was larger and could have more than 1 circuit, hard to know as no labelling.

What tests and checks have you done and at what times
Is the fault / problem occurring at regular or random times throughout the day
Is this site on a 3 phase supply

 

[James]

has anybody tested the coffee machine for safety?
I would try putting a normal load on the same supply as the monitor and see if that goes off at the same time.
sounds like it could be electrical interference forcing the monitor into black screen for a moment?