Electrical brownouts

arknor · 16 Jul 2013 at 13:33

ic1male said:
We had one today at dinner. Everyone's alarms went off, the microwave clock reset, the toaster could barely toast and my desktop fan was whirring pathetically slow. I thought it was broke.

After about ten minutes everything returned to normal functionality. I've never in my life experienced such a thing before. Needless to say, I had to research on the web to see what was happening and it turns out it could have been a brownout where the voltage drops. I didn't realise they could last so long though. Normally just a wee second or two.

Anyone else ever had one?

they need to load balance the grid.
everytime eastenders finishes they reroute loads of power because of all the people putting there kettles on.

when the grid demands more power than it can deliver you get a brownout.

theres a documentary on it on youtube or atleast the eastenders clip

EDIT:

Narj · 16 Jul 2013 at 13:36

The digital clocks in my house (alarm clock, microwave, oven etc) get reset about once a month lately. It's not the wiring in my house as it's all been redone recently, 17th edition, signed off etc. Neighbours across the road get the same too.

Best stock up on shotguns, bottle caps and tinned food!

LOAM · 16 Jul 2013 at 13:36

I read thread as "Electrical Browntrouts" came in wondering what to expect, then you said you had one for dinner :|

NZB · 16 Jul 2013 at 13:36

Only when i sneeze

arknor · 16 Jul 2013 at 14:01

LOAM said:
I read thread as "Electrical Browntrouts" came in wondering what to expect, then you said you had one for dinner :|

I believe it's when one is doing some electrical work and recieves an electrical surge through there body which leads to loss of bowel functions for a short period of time.
Just long enough for the "brown to leak out" hence an electrical brownout has taken place

Havana_UK · 16 Jul 2013 at 14:22

We've had one noticeable brownout before where the AC dropped to ~50V. Bear in mind that because of the way most modern electrical equipment works the AC voltage could drop as low as ~150V before you'd get any perceptible changes. One exception is incandescent lamps, which will just get dimmer with lower AC voltage.

Worth noting, however, is that any inverter-type load (e.g. an electrical motor) can be seriously damaged in a brownout, because they will draw more and more current as the voltage drops causing them to overheat, maybe catastrophically!

arknor · 16 Jul 2013 at 14:28

because most electrical motors are self cooling and won't be spinning fast enough?

Unicorn · 16 Jul 2013 at 15:03

As above its to do with grid load balancing at the end of major daily events many peaking turbines are standing by to go or running for the sudden surge of power required. Same happenes at the last whistle on football games the grid has real problems when football games go into extra time etc. the load cannot be sat idle on the grid we don't have storage for it so its got to be made available at the perfect time as millions of kettles are switched on if it wasn't dealt with correctly by the grid managing its demand from stations there would be local blackouts. If not it could be caused by any local problem overhead lines, fault transformer or even a strange line frequency problem

The Dread Pirate · 16 Jul 2013 at 15:07

Only when going to the toilet...

Seriously though happened a lot at my Workplace until the fault causing them was resolved we've had very few since then.

Energize · 16 Jul 2013 at 18:08

Rich1988 said:
for your entire house?

A single UPS will run everything in our living room, lights, tv, etc for ages.

MBennett · 16 Jul 2013 at 18:16

Firestar_3x said:
Good practice for the future, lets hope we can build enough nuclear stations in time

Not likely, the government seem to think fairy dust and magic makes the lights turn on and they do not need to do anything.

big_white_dog84 · 16 Jul 2013 at 19:08

It's most common where a single fuse blows on the 11,000volt overhead line. The other two phases stay in, and because of three phase theory and vector diagrams I can't create here some houses (66% or is it 33%?) see low volts while the others carry on merrily. Usually this would last longer than 10 mins because everybody assumes that we know that the fuse has blown - we don't know until you phone and tell us!