Mains Power Fluctuation Question

[Taffycat]

We had some problems with our electricity supply today - the same thing happened at the beginning of December. The power kept fluctuating, causing lights to dim for several minutes, before returning to full brightness. The problem lasted for several hours on both occasions and affected other electrical appliances, such as the microwave (which kept slowing-down and "struggling.") The PC happened to be switched off and unplugged on both occasions, fortunately.

I know that surges can be bad news (so we always connect through a surge protector) but I wondered how "drops" in power (not complete outages) would affect a PC in use? Would it corrupt/damage hardware, or just slow everything down? Hope this question isn't too daft to ask, I'd just like to know the potential hazards if anyone can tell me please?

By the way, an Inspector from the Electricity Supplier carried out some tests and assured us that the problem was "external" so they will be investigating further.

Thanks for reading this I appreciate it

 

[muckshifter]

Nasty stuff is our Electricity ... 240V + - 10% ... you can do the maths.


A "drop" in supply ain't as bad as a surge ... a drop in power would proably just shut the PC down ... however, one spike OTT and puff, dead PC ... 2amp fuses anyone? you can buy them.

Your 3amp fuse has a rating of up-to 700Watts

It is "recommended" that you use a 5amp fuse for PCs ... hmmm?

Did you know ... a 500W Halogen lamp only needs a 3amp fuse ... it is usually fitted with a 5amp though, to compensate the "surge" needed when you switch it on.


oh ... and a fuse is only there to protect the flex ... that is, so you don't melt the wire going to the fire.

Sorry Taffy, not laughing at you, or your demise ... I been singing this song for a long time.

 

[Taffycat]

Thank you Mucks, I'm grateful for your reply I'd rather know about these things than have hubby come in here to find a pair of smoking shoes with just a heap of charcoal (formerly me) in them

I didn't know about the 2 amp fuses - but will now look out for some, because if they would offer greater protection for the PC then I'm all for that

Anyway, after reading your post, I decided to check out our two halogen desk lamps and guess what ... they are 35W but have been (factory) fitted with 13 amp fuses! Think I'd better change them tomorrow.

May I say that it's nice to see you Mucks and thank you for your help

 

[muckshifter]

... lesson two

... but will now look out for some, because if they would offer greater protection for the PC then I'm all for that

Nope, don't bother ... 5amp for the PC & monitor will do, 3amp for everything else.

Let me just say again ... the fuse in a plug is not there to "protect" your equipment ... it is there to protect the wire that carries the current. That is what the STDs calls for, if the fuse blows before it "burns-out" your electrical item, then better for you.

One of my pet hates is, the 13amp fuse fitted plug ... damn stupid to sell these for a bedside lamp or an alarm clock. No wonder we have so many house fires.

Your modern "ring mains" sockets typically carry 32amp of power ... that is the current they carry, it is 7,200W (7.2KW) Now, go around your house and add-up all the appliances downstairs only, upstairs should be on it's own "ring" ... if they add-up to more than 30-32amps you risk the mains circutbreaker tripping ... you do have a modern Mains Fusebox with fuses that have little buttons on them? Every time one of these "pops" there was an "overload" ... that is probably due to too many electrical appliances on all at once. Are we taught this in schools?

Sorry to say, but there is a catch 22 ... you typically use a fuse that is over-rated for any appliance. So, for a bedside lamp we use a 3amp fuse, which is rated up to 700W ... can you see what I'm saying, who the Feck has a 700W bedside lamp?

Be assured that, Watts don't kill, Amps do.

 

[Abarbarian]

Been using a ups I got from e-bay for £25 for three years now . Its savedd my pc from 2 power cuts and twice when I forgot to feed the lecy meter . The Bulldog software shut down the pc sweetly and no damage or loss of data was done .
You've paid out mega bucks for your pc and spent hours setting it up and a UPS can cost as little as £75 .

http://catalog.belkin.com/IWCatSectionView.process?Section_Id=201476

 

[Taffycat]

Anyway, after reading your post, I decided to check out our two halogen desk lamps and guess what ... they are 35W but have been (factory) fitted with 13 amp fuses! Think I'd better change them tomorrow.

Ooh dear, I really shouldn't post so late at night - and without giving my specs a polish first

when I checked again, I found that I'd failed to see the little sticker which said that there were, in fact, 3 amp fuses fitted

Thank you for explaining things so clearly Mucks, looking around, I really can see what you mean about adding up the amps being used by various appliances - it makes very good sense, because it's easy to lose track of just how many electrical gizmos are in operation around the home.

You've paid out mega bucks for your pc and spent hours setting it up and a UPS can cost as little as £75 .

Thank you for the link an Uninterrupted Power Supply sounds like a clever device, particularly when it can provide a bit of extra time to save and close down properly in the event of any power losses. Thank you