Small spark when plugging stuff in ?

[TxPowderCoater]

My moms house is a small 2 bedroom in the country, wired by her bf 15 yrs ago, no inspections. When she plugs in small appliances etc , turned off, no load, she gets a small spark at the wall socket, been that way for a long time, just gets worse this time of year. She said she was told its reversed polarity by somebody, but I dont think so, since she has had a very nice generator wired in 3 years ago and I'm sure something odd like that would have been noticed then. Anyways, is this a sign of bad grounding? Should I look and see if she has any ground rods etc, I cant ask the bf if he put em in the slab since he's dead and gone.
thanks!

 

[theoldwizard1]

Reverse polarity is nothing to ignore !

A tester only costs a buck or two. Buy one and check all of the outlets, ASAP !!

 

[frank1380]

This is what you are looking for so you can check the receptacles.

http://www.harborfreight.com/electric-receptacle-tester-32906.html

 

[TxPowderCoater]

sweet! thanks, I have a VOM, ill pick up the tester from HF too and go check it out for her.

 

[Charles (in GA)]

Lowes, Home Depot, Sears, virtually everyone has these testers for pretty cheap. I've picked up a couple at the flea market. Spend the money and get one with the GFCI tester button in it. It will trip the GFCI breaker or receptacle when you push the button.

Charles

 

[Tom McDermott]

Possibly static electricity. Plugging in an object essentially grounds it for static. It's worse in the winter due to lower humidity.

-- Tom

 

[Milton Shaw]

A small spark is normal for some items. such as power supply for laptops. I notice one just about every time I plug one in. Worry if he plug gets hot from use from worn out contacts. Look for burning on end of plug etc. Probably nothing to worry about.

 

[rlitman]

A small spark is normal for some items. such as power supply for laptops. I notice one just about every time I plug one in. Worry if he plug gets hot from use from worn out contacts. Look for burning on end of plug etc. Probably nothing to worry about.

THIS, not something like reversed polarity. There is no such thing as reversed polarity in AC.
Most newer power supplies do this. It is a side effect of their being more power efficient.

 

[TxPowderCoater]

THIS, not something like reversed polarity. There is no such thing as reversed polarity in AC.
Most newer power supplies do this. It is a side effect of their being more power efficient.

yes, but this is with plugging in something totally off like a small fan, etc...I think its a grounding issues , static electricity issue maybe.
I dunno, I will update after friday and let yall know what I find when I check around the place.

 

[Greatbear]

If an appliance has some sort of line filtering built in, you'll get a spark when you plug them in even when off due to small capacitors charging. Electronic devices and appliances that have a 'standby' mode will also do this, since the units are not truly "off", but in a reduced power state. PCs are very prone to this.

 

[JimVonBaden]

Possibly static electricity. Plugging in an object essentially grounds it for static. It's worse in the winter due to lower humidity.

-- Tom

This would be my guess, with no other info available.

Jim

 

[housey]

THIS, not something like reversed polarity. There is no such thing as reversed polarity in AC.
Most newer power supplies do this. It is a side effect of their being more power efficient.

Maybe by reversed polarity they meant that the switch is controlling the neutral instead of the active?

Some appliances will still work if this happens, but it could mean that the switch is only operating the neutral and not the active. This would mean that plugging an appliance in, even whilst the switch is in the off position, would energise the appliance to whatever voltage it is over there. It still won't turn on until the switch is closed obviously and continuity is made between the neutral and active, but it could cause a spark as it brings the internal circuit of the appliance up to the same voltage potential as your consumer mains?

 

[Tscott]

If what your plugging in is switched off, then you should see no spark as there is no path for current to flow to. If what you plug in is switched on, then I would expect to see a spark just as the contacts come together in the receptacle. If it happens all the time then I would guess some sort of capacitive build up in the receptacles.

Tom

 

[nehog]

If what your plugging in is switched off, then you should see no spark as there is no path for current to flow to. ...

Depends on the device, many electronic devices do draw power when 'off' for various reasons. It is not uncommon for the power supply to be constantly on, and the power switch to be on the output side of the power supply.

Also some items have capacitors and (sometimes) inductors in the AC line where it enters the enclosure. This is done to minimize RFI (radio frequency interference) and those capacitors can cause small sparking when the item is plugged in.

The important two questions are:

1. What device gives the spark? (exactly, make and model if possible), and

2. Where is the spark observed?

 

[rlitman]

Maybe by reversed polarity they meant that the switch is controlling the neutral instead of the active?

Some appliances will still work if this happens, but it could mean that the switch is only operating the neutral and not the active. This would mean that plugging an appliance in, even whilst the switch is in the off position, would energise the appliance to whatever voltage it is over there. It still won't turn on until the switch is closed obviously and continuity is made between the neutral and active, but it could cause a spark as it brings the internal circuit of the appliance up to the same voltage potential as your consumer mains?

Umm, still nope. You're not bringing a device "up" to a voltage when it's plugged in with a disconnected neutral. Alternating current "alternates".
It goes "up", it goes "down", and does that all 60 times a second.

 

[TxPowderCoater]

I went a bought the plug in tester from Lowes and I will go up there on friday and then report back what I find. thanks for all the input guys.

 

[rodm1]

If she has 3 prong outlets try to rock the plug sow the ground connects first. It doesn't sound like a problem unless you are getting burnt outlets or plugs.

 

[Teken]

If an appliance has some sort of line filtering built in, you'll get a spark when you plug them in even when off due to small capacitors charging. Electronic devices and appliances that have a 'standby' mode will also do this, since the units are not truly "off", but in a reduced power state. PCs are very prone to this.

Depends on the device, many electronic devices do draw power when 'off' for various reasons. It is not uncommon for the power supply to be constantly on, and the power switch to be on the output side of the power supply.

Also some items have capacitors and (sometimes) inductors in the AC line where it enters the enclosure. This is done to minimize RFI (radio frequency interference) and those capacitors can cause small sparking when the item is plugged in.

The important two questions are:

1. What device gives the spark? (exactly, make and model if possible), and

2. Where is the spark observed?

Both of these replies are correct. If the device has some sort of filtering which employs capacitors depending upon how it is arranged and where it is in the power supply the charge / discharge from the internal capacitor will cause this *spark* to happen.

Having said that: If you take a laptop transformer and plug it in with out the computer being attached you will rarely see a spark. Take the same transformer and leave the *running* computer on, all the while plugging in the transformer (depends upon maker) you will see a spark.

This problem should NOT be ignored to those who work in the garage in a confined space where they are using materials which off gas and can lead to a potential explosion.

Two cases of this have occurred in my country due to this exact problem.

Teken . . .

 

[housey]

Umm, still nope. You're not bringing a device "up" to a voltage when it's plugged in with a disconnected neutral. Alternating current "alternates".
It goes "up", it goes "down", and does that all 60 times a second.

Whether its AC or DC is irrelevant isn't it? If its cycling at 60Hz and it happens to be at say 110V at the instant it becomes close enough for current to flow, then it will act the same way as constant 110V DC for that split second and a small charging current could flow to bridge the potential difference between the device and the consumer mains, how much current flows would depend on the capacitance of the device.

I could easily be wrong though as Im definately no expert, or the voltage/current that does flow could be so negligible that it doesnt create any spark. Regardless that is still the first thing I would test for if if someone had previously said the polarity had been reversed, even though technically the polarity is always reversing, being AC.

 

[rabidsquirrel]

This problem should NOT be ignored to those who work in the garage in a confined space where they are using materials which off gas and can lead to a potential explosion.

Than they should also have all explosion proof fixtures, switches, and receptacles. Nearly everything we plug in will have a small arc, and we usually can't see it.

I agree that we need to be careful around explosive vapors and dust, but he really has nothing to worry about.

If he's drawing a three foot long arc and needs to hold the plug with both hands to force it into the receptacle, he may have a problem worth looking into.

 

[Teken]

Than they should also have all explosion proof fixtures, switches, and receptacles. Nearly everything we plug in will have a small arc, and we usually can't see it.

I agree that we need to be careful around explosive vapors and dust, but he really has nothing to worry about.

If he's drawing a three foot long arc and needs to hold the plug with both hands to force it into the receptacle, he may have a problem worth looking into.

I would pay good money to see that 3 foot arc!

 

[TxPowderCoater]

ok guys, I went and had a look see, its wired correctly as far as neutral, hot and ground....well... it does have every switch and plug wired push in style and thats the issue, 20 yrs later, there is corrosion building on the tiny fingers that grab the wire, anyways, with the plugs wired in a string, all of em are drawing their load through the other and so on and so forth. My first thing is I am going to start at one end of the house (small 2 bedroom) and start wiring them correctly with lugs and screw terminals on the sides.
that should do away with drawing through one to the other and also have better connections blah blah blah

Thanks again for all the answers, the little meter worked, even checked my home with it

 

[Provincial]

Another way to do this is to hook the two existing wires together with an added short wire that goes to the recepticle. Use a wire nut to tie the three wires together. The nice thing about this is that replacing the recepticle in the future is easier, and you don't have to break the wiring to the other items in the circuit.

You can get recepticles that clamp the wires when you tighten the screw. This is easier than wrapping the wire around the screw. They are hard to find in the "tamper resistant" verson, which in now required for residential installations.

Tamper resistant recepticles are another example of the NEC trying to undermine Darwin.

 

[rabidsquirrel]

Tamper resistant recepticles are another example of the NEC trying to undermine Darwin.

It isn't the NEC, it's the manufacturers. I refuse to put them in my house.