Surges/tripping rcd/kitchen light/blown bulbs

[kensplace]

Sometimes when the kitchen light (tube) is turned off, the rcd's on the computer / tv equipment upstairs trip.

Its definately the tube being switched off, as I have a camera pointing at the door where the switch is, and you can actually see the spike interference in the exact frame where the switch is turned off - and at that point the rcd trips just after.

What is the likely cause? Would replacing the switch fix it, or is surge protection needed at the switch or light itself? Could their be a problem with the light/starter?

Our house also keeps blowing light bulbs on a fairly regular basis - its a pain, but electrician could not find anything wrong last time he was here. - could it be the surge from the switch/light that blows bulbs or shortens life?

 

[industryspark]

oooo er this one sounds spooky.

when you say rcd do you mean the rcd protecting the ring main upstairs (i.e, the one in the consumer unit)???

or are you meaning a plug in rcd?

light bulbs blowing frequently can be a sign of a bad connection but surelly your sparky would have found this. where do you buy your lightbulbs from?(serious question)

 

[kensplace]

We have a couple of plug in rcd's from wilki's, the little ones with reset/test buttons. They trip about once a day, maybe once every two days at best.
Occasionally when a bulb blows it will knock off the main light fuse in hallway, requiring it to be switched up again before the lights work again.

Light bulbs have been tried from local corner shop, and local hardware store, maybe more expensive bulbs would help?

Sparky did find a few problems when he was here last, but fixed them, no joy finding a cause for the bulbs though, but just figured out that its the kitchen light tripping the rcd's recently, so he would not have been aware of that.

 

[Steve]

When a bulb blows it produces a near-short circuit for a short period, which can be enough to trip its MCB. Nothing unusual here.

The RCD issue though, firstly, i'd ask you to stop putting RCDs in series with one another, if this is what you're doing. Its not helping matters and has no advantage. Check the earthing on the fluorescent lamp, make sure all its connections are ok.

 

[Taylortwocities]

Do you mean that your lighting circuit goes through the RCD?

TTC

 

[bernardgreen]

Sometimes when the kitchen light (tube) is turned off, the rcd's on the computer / tv equipment upstairs trip.

Most computer and TV type power units have filter circuits on the mains input which have capacitors between Live and Earth and between neutral and Earth. These capacitors, mainly the ones Live to Earth create a small amount of "earth leakage current" which in normal use is too low to trip a 30 mA RCCD. But a transient voltage spike on the mains wiring such as the disconnection of the supply to the choke ( inductor ) in a fluorescent light may take the "earth leakage" in the computor's filters high enough to trip the RCCB.

Check the power factor capacitor in the fluorescent light is connected.

The "earth leakage" in mains filters becomes significant when there are several such filters. I recall an office where turning on the 10th computer would invariably trip the RCCD, any 9 out of the 11 and all was OK but any 10 out of 11 killed the power. The ring was moved to a 100mA RCCD and each cluster of work stations had its own 30 mA RCCD.

Bernard

Sharnbrook

 

[kensplace]

There is one rcd protecting the tv/dvd/cctv power, and another, on a different mains socket at other side of room, protecting a pc system.

The lighting isnt on the same circuit as the rcd, but getting spikes anyways.

Will take a look at the light later, see what I can see, thanks all.

 

[Steve]

There is one rcd protecting the tv/dvd/cctv power, and another, on a different mains socket at other side of room, protecting a pc system.

Why? Are these items outside of the equipotential zone? If not (and I doubt it anyway), then there is really no point WSE in protecting them with an RCD.

And the sockets in question, are they RCD protected? If so, there is no point in plugging a plug-in RCD into them.