When I switch my kettle off at the electric socket, a brief flash of green light is visible behind the socket. Is this normal, or could it be dangerous? Supposedly it's ok if the kettle plug is earthed?
Adam.
On 2/26/2009 11:06 AM Hobbyist spake thus:
Flashes of light accompanying switching something on or off are *never* OK. Indicates arcing contacts, which can only get worse with time.
Not sure where or what kind of switch you have; "switch my kettle off at the electric socket" is a bit ambiguous. But it's time to replace that switch if it sparks. "Earthing" (aka grounding) won't help you here.
Thanks, David. I'll call an electrician, and meantime I'll use a different socket (with on/switch on the socket - when it's on, you see the part of the switch that is painted red, otherwise it's white when pressed the other way - not sure if that explains it. I'm in England).
Adam.
Hobbyist asked:
It sounds like there is a loose connection to the socket. I suggest you have it checked before you have a fire.
---MIKE---
On 2/26/2009 11:43 AM Hobbyist spake thus:
So it's a receptacle with a switch inbuilt, right? Should be easy to replace.
Thanks for your advice, Mike. Had a minor fire a few years back, caused by lightning, so I don't want another. I'm definitely calling that electrician.
So, I'm using one of these Intermatic timers ahead of my home Bunn coffee maker to remove power from it during the night. That saves us a little electricity by not keep the water at brewing temperature all the time.
If I turn the timer dial by hand, when it switches power off I can see a small spark through the opening the overide control knob protrudes through.
Yet, you say such flashes are *never* OK.
I don't agree. Have you ever closely watched the contacts of a relay controlling a few hundred watts of load? When the contacts open there is almost always a small visible spark.
I agree with you that arcing contacts will only get worse with time, but sometimes there's no easy way to eliminate that arcing, and that "time" can often be measured in years. That's why we had to change out the distributor points in our cars when they got blown away by the sparks occuring every time they switched.
But, that was before they started using solid state switching for that job, wasn't it?
Jeff
Any time a switch makes or breaks a contact while under a load, it will cause an arc. Typically you can't see it, because it's enclosed inside the device, but it exists and is perfectly normal. That being said, there could still be something wrong with the device or the connection, so having a professional look at it is a good idea
Wouldn't bother me. You just cut the power, it can't hurt anything.
On 2/26/2009 1:10 PM Jeff Wisnia spake thus:
Point taken; I guess it's a matter of degree. Some sparking with relay contacts switching a large load are, as you say, normal. I think the green sparks the O.P. saw were a little more dangerous. Hard to say exactly where to draw the line; I'd say if there's a significant amount of sputtering or sizzling sounds emanating from the device, it's not good.
I believe kettles are relatively high watt loads. And with 230V the arc may be larger. Could be entirely normal. Or possibly not.
A better place to ask the question is probably uk.d-i-y Last I saw it was a very active newsgroup and handled UK electrical questions. This newsgroup is primarily US and Canada. It is really surprising how much different the electrical practice in the UK is. For instance sockets do not have switches this side the pond. And we do not have 32A general use branch circuits and never ring circuits.
It sounded like England. For those who don't know we have
240V and an switch built into the outlet to turn the power on and off. I would guess your kettle is approaching or exceeding the capacity of the switch part or the switch is just getting old and replacing it as you plan should take care of it.Some small spark is normal however.
On 2/27/2009 7:15 AM bud-- spake thus:
Ackshooly, the OP seems to have gotten good answers here.
Well, we (North America) *can* have switched sockets; the devices are available, and I've seen them in homes, even installed them myself, but it's true they're not common. And yes, no 32 A (!!!) branch circuits and the exceedingly *weird* ring circuits. Leave it to the Brits ...
However, I will say that 230/240 volts is more efficient than our 120. (Less I^^2 R loss.)
Except they have 50 cycle power. Bigger transformers needed.
TDD
A flash from a switch is normal, especially if it is switching a load. If yours had a sustained arc, that would be something to worry about. I have increased the life of switches and other contacts by using diodes, resistors, capacitors or MOV's to suppress the arc. I have an adorable little electric kettle that draws 800 watts at 120 volts AC. Of course we colonial Hillbillies drink ice tea. *snicker*
On 2/27/2009 6:31 PM The Daring Dufas spake thus:
Surely not by much, though.
Have you ever seen the transformers used in 400 cycle AC systems? They're tiny things used mostly in aircraft power systems.
TDD
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