Spark...why?

[ablebaker]

When I plug a tool or vacuum into my shop plugs I get a spark just as the plug goes into the recepticle...I wonder why this occurs - not all the time but frequently.

 

[gatchel]

With the tools off...Static electricity maybe? Not sure.

 

[rabidsquirrel]

That's the electricity arcing from the receptacle to the plug before full contact is made. Only happens when there is a load on the cord you're plugging in, nothing to worry about.

 

[mrb]

if the contacts are loose, dirty, corroded, or heavily oxidized the spark will be more significant to the point where it can erode metal on the contacts which then causes a bigger spark, which causes more erosion, etc. If your receptacle is loose (its too easy to pull the plug out) replace it.

best to not plug in things that are already on if it can be avoided.

 

[MrMark]

It is normal but not a good thing to have happen. If it is a compressor that is under load and you plug it in and it's ready to cycle on you will literally arc weld. That is because the inrush current on that motor under load is enormous for a very brief period of time - in other words it looks and acts just like a welder.