Finding a break in an electrical cord?

[Carmudgeon]

I've got a couple electrical cords that have breaks in them.

One, a longer ~75' extension cord, and the other on an old beater vacuum I use in the garage, on the car, and other places where the shop vac isn't necessary.

Any suggestions? Most of what I've found isn't too helpful, beyond a careful physical examination.

Would a non-contact voltage detector work?

I'm happy to try a cheap detector from HF, before hacking the cord, or replacing it. The vacuum cord would be a tougher task.

 

[eljefino]

You could plug the item in, turn it "on", and massage the cord. If you make temporary contact it might try to power up. Watch for flickering lights on the same circuit.

Odds are the break is near the plug, so you could cut it a foot shorter and wire up a new plug.

But then if it wore out in one spot, it may have worn thin in another, and would just be trouble brewing. A vacuum is a huge power draw and not worth the risk.

 

[RooflessVW]

Replace the cords.

 

[brianl703]

Try this

https://www.harborfreight.com/cable-tracker-94181.html

If you run the probe along the length of the cable you should reach a spot where the tone is weaker. That's about where the break is.

 

[pcoxe]

Most likely a bad plug or receptacle end. If the cable in-between is in good shape, you could install new ends. Probably will be nearly the cost of a new cord if you use high grade Hubbell stuff.

 

[Wolf359]

Normally you'd use something like a time domain reflectometer. But the cost of the device is probably too high for this application.

 

[PandaBear]

At work for small traces we use xray, but for a 75' cord that's low cost (i.e. less than $100), just throw it away and get another one. You cannot fix it cheaper than the diagnostic time and the material cost to replace it.

Is it intermittent or is it permanently broken? If permanent I'd take the plug apart and start reconnecting it and see if the ends are bad, and if it doesn't fix it just throw it away.

 

[Carmudgeon]

Thanks all.

Neither are particularly worth the cost to do deep dives, but I wanted to see if I was missing an obvious solution. I'll give the simple tactics a shot, and if they aren't successful, not problem.

 

[nomas]

Normally you'd use something like a time domain reflectometer. But the cost of the device is probably too high for this application.

Mmmm..." normally " you would not . 40 yrs in the business and never saw a TDR used to test an extension cord . Can you ? Sure , if you have one . How many people do ?

 

[PimTac]

I’ve done this before. Plug a trouble light into the cord and as someone mentioned, move up the cord bending it and such until you find the spot. That’s when the light will flicker. Most of the time it’s near the ends due to pulling etc.

 

[SHOZ]

A good voltage detector will find it (Fluke). A cheap one is scared to death of any electrify and not much good.