Hair dryer shoot sparks

R

RMELECT

Member
Location
New England (USA)
Occupation
Electrician
Good afternoon,

This was my morning at a local HS Cosmetology class. As the story from the teacher and student goes.. The student was using the hair dryer and when she went to unplug the hair dryer (turned off), it shot off sparks across the counter. The student did not get zapped but did have marks on her wrist. The hair dryer is commercial grade with GFI plug attachment. Checked all connections, counter outlet enclosure is grounded and all screws and hardware tight. It left pit marks on the hot side of the plug in prong and also the enclosure. Voltage is 120v and everything metered correctly. Inside of the enclosure had no burn marks.

The hair dryer works fine now:unsure:.... Tested it for a while and ran it through the ringer and working fine. I have my ideas but just throwing this out for a second or third opinion.

Thanks
 

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I agree with Hal. There is a relatively large distance between the hot prong, still in the receptacle, and the top of the enclosure. Was there some type of gel on her hands?
 
That's what I first thought... Maybe a bobby pin or paper clip. The student had a braclet on but it had no marks. Could not find anything laying around that may have caused it. To make pit marks like that it would have to be something metal between the two. The prongs are rugged and the distence between the prong and top of the enclosure are to far from each other.
Just wanted a few opinions but ill sleep good tonight.

Thanks boys
 
I'd be looking on the ground for a metal comb, scissor or brush handle with 2 little weld marks. Or a big hoop earring (again, metal). Something conductive bridged the hot blade and receptacle cover.
 
I looked everywhere and asked all the right questions. They said it was off and shot sparks unill they smacked it with a plastic trash can.
 
Either they (or just the student) are not telling everything, or something fell after they "smacked" it with the garbage can. Odd that the breaker didn't trip if the box was grounded. Didn't hear whether the GFCI (or whatever it's called) on the cord tripped or not.
 
Little Bill said:
Didn't hear whether the GFCI (or whatever it's called) on the cord tripped or not.
Click to expand...
Fault was "up stream" of the cord mounted protection.

However this very possibly in a location that should have had GFCI protection on the receptacle anyway. Even if some "grandfathered" location that once didn't require GFCI, I have installed GFCI in many locations in older school facilities to comply with newer codes because their insurance company wanted them to do so. Some cases maybe even where code did not specifically require it at the time.
 
I would like to derail this thread by stating that this wouldn't have happened if the receptacle was installed ground up :p
 
Small piece of metalized Mylar, maybe confetti or even glitter that was in someone’s hair and landed in just the right spot. It would have been vaporized without leaving anything but the marks.
 
Appears the receptacle is not the problem but I have a hand held double ended male plug to test blade tension. One end has a single nylon blade for checking slot for grounded conductor & energized slot.I would check the receptacle with it . Hospital that I retired from had one to measure ground pin tension & voltage ( very expensive & broke at least once a year ). My hospital has a policy that all receptacles be installed with ground up. Safer if a non.metslluc wall plate is used. With a magnifying glass could you see any signs of arcing, burnt marks or hot spots inside of commercial dryer ? I never attempted to megger using 250 or 500 volt DC test voltage thru a plug mounted GFCI thinking the higher voltage would damage electronics.
 
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