In repairing a hair dryer which was working intermittently, I found a break in the copper wiring inside the power cable. There was no external damage to the cable to suggest that anything had happened post production. The only thing I can think of is that during production of the power cable one reel of copper wire ended and the next started.
Can anyone confirm that such an occurrence is possible?
Some appliances often suffer that kind of break, push along vacuum cleaners to name just one.
Very unlikely - that would have been a hot spot and the insulation would have been damaged.
More likely a problem where the wire was flexed too often- I usually see these breaks near the strain relief for example.
John :-#)#
--
(Please post followups or tech enquiries to the newsgroup)
John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9
Call (604)872-5757 or Fax 872-2010 (Pinballs, Jukes, Video Games)
www.flippers.com
"Old pinballers never die, they just flip out."
I've seen it before. it made no sense to me either. The only thing I could come up with was it crap junk wire and somebody tugged it or tripped on the cord pulling the strands apart.
It might be like a hard disk. they fail just sitting there, but physically destroying one is actually pretty hard when you want to do it.
Electric drills, GHDs to name a couple more. There is seldom any external signs of stress at the point where the break has occured. In my experience, hairdryers are one of the more common items to suffer from this.
Arfa
Cables do break like this, have seen it before. Usually metal fatigue from flexing. Metal fatigue will happen in a LOT less number of flexes than PVC insulation "fatigue".
On the other hand, it is possible that there was some kind of break, weak point or many strands were broken in manufacturing, or some other weird thing happened on the assembly line but this would likely cause arcing and visible heat stress to the cable such as blackening on the inside and melting- especially with something that pulls a few amps like a hair dryer ?
(...)
At my previous job, the lab manager would pull on DMM test leads until the wire inside broke. The silicone insulation looked just fine to the naked eye and the broken probes would yield intermittent and / or nonsense readings.
--Winston
ElectronDepot website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.