Flickering lights??

[sstear]

Ok so although im qualified i dont do electrics all day every day so this may even be a silly question but here goes:

Replaced a couple of light switches in a friends house a couple months ago, now when i switched one on, the lights flickered for a second before staying on constant, i thought it was weird but on using the switch a few more times didn't i see it again, so i told them just to keep an eye on it.

They told me its happened a couple of times since but not for very long and not amazingly often, now tonight they've called to let me know more than half the lights in the house are doing the same thing but without being switched?

im assuming this is a supply issue? gunna go take a look at the weekend and see if its anything obvious in the consumer unit but is there anything i should be specifically looking out for? and whats the best way to test the supply for possible overuse? i mean they have quite a few multi-bulb light units but none of the appliances are newer than a few years old so i highly doubt the circuits being overloaded?

Any help would be greatly appreciated!

 

[Sintra]

One way or two way switching?
What type of lamps?

 

[sstear]

One way or two way switching?
What type of lamps?

2-3 circuits are affected from what they told me so there mainly one way but the first one to do it was on two way switching, from what they said all of the lights that flicker are incandescent lamps, the 12v's in the kitchen are fine

 

[NickD]

im assuming this is a supply issue?

What does a desk/table lamp with incandescent bulb in it do, does that flicker too?

whats the best way to test the supply for possible overuse? i mean they have quite a few multi-bulb light units but none of the appliances are newer than a few years old so i highly doubt the circuits being overloaded?

Work it out from the sum of the bulb wattages. If it was a problem caused by overload, the more lights you turned off, the more the problem would go away. Seems to me an overload is pretty unlikely to cause bulb flicker.

 

[SPARK2B]

TRAINEE ALERT, puh--leeese be gentle!!!!.....


please be gentle....im probably way off...**trainee** does capacitive coupling only affect low energy lamps (cheep ones with no capacitor fitted ?)

we only touched on it @ college on a day the lecturer was off, was told we would revisit later..

please be gentle, to the trainee, and post any info / corrections to what i have asked...

thanks all

***now tonight they've called to let me know more than half the lights in the house
are doing the same thing but without being switched?**...<<<--------.this is what got my attention

 

[NickD]

TRAINEE ALERT, puh--leeese be gentle!!!!.....

I have plumped the pillows, turned the lights down low, put Barry White on the stereo, put the furry covers on the manacles and even warmed up the Vaseline pot specially.

please be gentle....im probably way off...**trainee** does capacitive coupling only affect low energy lamps (cheep ones with no capacitor fitted ?)

No idea what you mean without some context. Any two bits of metal with insulator between them do capacitive coupling. If I had the foil off a Kit Kat, right, and there was a car key for a Daewoo Nubira floating out between the orbits of Jupiter and Saturn, they would be capacitively coupled. Not much, I grant you.

 

[SPARK2B]

like i said we only visited it briefly, i remember being told that capacitive coupling could generate enough charge to reach strike point for the low energy bulbs (the cheeper ones) so they'd flicker, (EVEN WITH SWITCH SET TO OFF) the poster mentioned that the lamps in question were incandescent, which is why i asked if those types of lamps are affected by capacitive coupling / strike point.....the lecturer also said that a lot of electricians dont know about it (the issue with the low energy bulbs, cap coupling,...

but to go back, the main q i had was does this phenomena affect the old style filament lamps ( as i remember it now, i dont think it does)

jus a thought about this problem,....remember, TRAINEE (-:

worth a try, i thought, and a chance to learn.

 

[Richard Burns]

Whilst any circuit can be subject to capacitative coupling with incandescent lamps if there is a very small amount of power present they will just pass the current through and because it is low they will show no visible sign, possibly if you measured the ambient temperature and the temperature of the filament you may find the filament slightly warmer.
With electronically controlled lamps the internal capacitors can accept enough charge from this low power to be able to then release it in one burst and cause the lamp to light briefly, this then discharges the capacitor and the cycle starts again.
If the lights are sufficiently low power such as LEDs then the lamp can light dimly all the time.

For the Op it sounds like there is a loose connection that is occasionally failing and causing the lights to flicker.
As the time goes on the connection is getting worse and causing more problems. I would initially suspect the first lighting circuit, but, because other circuits are being affected it might be before them all in the CU.
A higher than usual resistance measurement may be notable on testing, and there may be signs of over heating at a connection.

 

[SPARK2B]

well, i tried.:yesnod:

 

[7029 dave]

Sounds like loose connection somewhere.

 

[R G]

Im waiting for Old Jag to give us his technical opinion on this one ,,,,

 

[willy fixit]

I'm in the dodgy connection camp!

I had a fluorescent mirror light in a bathroom that the customer said flickered occasionally (when switched off) Took it apart and put the manufacturers single pole sw in the line instead of N and its fine now - I guessed it was induced voltage - is that the same as capacitive coupling?

 

[pjcomp]

This all began when the OP replaced a couple of light switches. Loose connections? New light switches? Anyone else see a pattern here?

pj