Small Flash from my power point

[Jason Steele]

Hi All,

Every now and then I have noticed a small flash from one of my power points when I switch it off. Is this anything I should be worried about.

[Auld Bassoon]

I'd have a sparky check it out

[Ashore]

Dirty fluff dust etc, old worn contacts , insulation breakdown or one of many others , proberly needs replacing , this should be done by a licenced electrician,


Rgds

[Jason Steele]

Thanks for the feedback.
We have only been in the house a short while and the P/Points all look brand new..

Cheers

[Barry_White]

I wouldn't be too concerned about it. I have several points in my house that do that, mainly when switching off an appliance that is drawing a fair bit of current such as a heater and is caused by the contacts breaking.

This is not always visible depending on the amount of surrounding light at the time. I have had this happen on brand new power points

[BrisBen]

Hi there

Have you checked the monitor connection?

Maybe the last slide had a white screen

Maybe Doug slipped his avatar in when you weren't looking

Hang on)

Just realised we're talking electical outlets not software presentations!

I put this one under the same category as the humm that comes from fan switches next to a dimmer - kinda weird but it probably wont kill you - new points last november, full wiring check, only happens when I switch the heater off

[Greg Q]

Which brings up an interesting point...what are those switches rated at? They are puny in comparison to a switch that we have on even a 1 h.p. motor for example. Are we meant to be able to switch a 10 Amp load off and on with those dinky little switches? For how long?

Greg

[Redgy]

They are rated at 10amps but really you should switch your appliance off at the switch or control on the appliance if it has one, not the power point....if you keep switching on & off 10A loads you will reduce their life. AC supply has a peak voltage every 20ms and the current to your appliance follows this (for a resistive load) so if you happen to switch off at the exact point where peak current is flowing there could be some flash depending on the load type too. Same can happen at switch on for example many fluros on one light switch, in rush current at the peak of the voltage sine wave. Clipsal actually have special switch mechanisms for fluro lighting that are rated for such loads.

Redgy

Pics of an EXTREME example.....

[MICKYG]

Jason, if you see sparks such as in redgy's post you should take steps,

"Long ones and often"

You often see a small flash from a power point in certain light, but unable to advise as it depends on the circumstances at the time.

Regards Mike

[TrevorOwen]

Pics of an EXTREME example.....

Interesting photos Redgy. It doesn't look like a South Australian substation. Where is it out of interest?

Regards
Trevor

[Pulse]

I'm with Redgy and Bazza, try it with a 10A heater and most will spark a bit.

Pulse

[Markw]

One might think that the extreme examples are genuine but alas they are not.

1st pointer - where is the smoke from oxidizing copper from the air break switch terminal.

2nd pointer - an electric arc produces a flash and a plasma cloud. The cloud is black with a red centre. Certainly not a pretty white arc trail. If the camera can actually take the photo of the arc, the shutter will stop down so low that the surrounding scenery is dark.

3rd pointer - the air brake switch is designed to prevent this even if its peeing down with rain loaded full of contaminants. It just doesn't happen.

I have actually conducted arc testing of clothing & PPE used in the electricity industry - Tests at 415V 50kA at 0.5 sec. This makes a really big bang - lots of fun for the destructo types

[Redgy]

Mark, shots are from a video, maybe from the states somewhere. I think the video is real although it is most likely a deliberate setup to cause the effect. I spent 5 years in substation maintenance for ETSA (SA supply) and have seen plenty of strange & scary things that high voltage can do....which is why I bailed out :eek::eek::eek:. Anyway I'd like to send you the video (it's about 1.5meg) & see what you reckon....not trying to be a smartar*e, just see what you think....so if you want a look, PM me your email.

Cheers
Reg

[Master Splinter]

If you like high voltage sparks, try this site.

This is what they say about that video:

"...was captured by the maintenance foreman at the 500 kV Eldorado Substation near Boulder City, Nevada. It shows a three-phase motorized air disconnect switcher attempting to open high voltage being supplied to a large three phase shunt line reactor. The line reactor is the huge gray transformer-like object behind the truck at the far right at the end of the clip. Line reactors are large iron-core coils which are used to counteract the effects of line capacitance on long Extra High Voltage (EHV) transmission lines. Internally, this line reactor has three coils, one to handle each phase in the three-phase system. Each coil within the reactor can provide 33.3 Million Volt Amperes of compensating inductive reactance (MVAR) at 290 kV between each phase to ground . The power company had previously encountered difficulty interrupting one of the three phases when trying to disconnect the line reactor. The substation maintenance crew set up a special test so that they could videotape the switching event, and they made arrangements to "kill" the experiment, if necessary, by manually tripping upstream circuit breakers."

[Markw]

I stand corrected this does look to be authentic.

I had a look at where the video footage came from - thanks to M/Splinter's link and what your looking at is a man made version abliet by accident /damaged equipment, of lightning.

The equipment shown is an air break switch (electric contactor) used to turn off or on very large voltages - 500,000 of them with huge amperages. This is city sized power requirements. The system is supposed to have an inert gas arc extinguishing system (SF6 - Sulphur Hexafluouride - nasty stuff when burnt in an arc, the acid condensate will eat through to the bone). The gas extinguisher failed to operate while in a test mode and an induced current some 33,000,000 Volts backed up in the system to produce the arc which sort of developed into a Jacobs Ladder. The induced current is 66 times greater than what the system is designed to handle.

The reason there was no smoke from the arc was the minute number of amps only about 100A which was the operating current for the line reator (the long thin thing to the right of screen) where as the system normally takes (according to the text) about 2000A @ 500kV on a 94 mile cable. As the arc amps were only small it didn't do a lot of damge to the system. If you look at some of the other pics shown on M/Splinters link you'll see what a "hot" arc looks like and can do to machinery and structures. Good stuff

Thanks also to Redgy for the footage - greenies to you both