Lighting Goes Dim For A Few Seconds

[username#132]

Occasionally, the lighting in my room goes slightly dimmer for a couple of seconds and then back to normal. What could be causing this and why doesn't it effect my presumably sensitive computer equipment? Is this a "brown out"?

 

[supersparky]

not personally but it has a different effect on everyone

 

[Steve]

#132, this happens when someone in a building near you turns on a piece of equipment with a high current, or high start-up surge. For example, if there is a garage near you with arc welders and compressors, these can draw significant currents from the supply (100's of amps) during their operation.

Similarly, I have found that our DIY air conditioner has a very high startup current when the compressor kicks in (60-80A, judging by how dim our lights go in relation to the shower running at 45A), and the fridge freezer also takes a high current during compressor startup.

If your neighbours are fed by the same supply cable as you, they may also have these appliances, causing you "brownouts", though i dont think this is the correct term.

Undervoltage shouldn't affect your computer long term - its overvoltage you have to watch. Buy a surge protector or a UPS - when the voltage is too low, the UPS will kick in and protect your equipment. Nothing else you can do about it im afraid.

 

[username#132]

Thanks Crafty, I've got a surge protector already so I'll just make do with that for now (I'm on a student budget!).

Thank you too, sparky...