The mysterious extension cord

[tearapin]

So, I was using my blower last week which is electric. When I went to unplug it from the blower I noticed the end was really hot. Ok no problem because it is 100 degrees here. But then I noticed that the extension cord end was spongy. OK no problem I thought. I went to HD and picked up a Leviton end, cut off about 6 inches of wire and attached it.

I have one of those Gardner Bender electrical testers and it shows open ground. Hmmm, tested the outlet, just fine. Hmm again.

Then the girlfriend comes over and says "Hey I have a cord with the inner wires showing". I figured I could fix her cord just to see if the ground was open when I got done with hers. Installed an end on hers and no problem. Hmmm.

Took both ends of my cord as they are both replaced ends now. Pulled, looked at connections. Nothing seems wrong. Removed the end and re-replaced it just for grins. Same thing.

The odds of a broken ground wire somewhere in the cord seem slim to me. I am not sure how I would diagnose or find the break.

I am thinking this may be why the end got hot. So I fired up the now ungrounded blower today. Its 97 degrees. Used it and the end is not hot. But still the GB tester shows open ground.

Any ideas how to find the problem?

I do not use the blower in my bathtub but, this just bugs me.

 

[Lou's Garage]

Test for continuity with a multi-meter. Test each wire from one connector to the other. If you find an open, first remove one connector, then the other to eliminate the connectors and, finally, just check the wires themselves. Finding exactly where the open is within the wire probably isn't worth the trouble. I'd probably just replace the extension cord.

Following are some ideas how you might look for an open within the wire: You might be able to find it with a TDR (time domain reflectometer) but that's usually used for coax. You might try a short tester designed for checking within wiring harnesses on automobiles. Investigate any old repairs. Try stretching the cable in short sections and see if you find a "stretchy" section. Or, just cut a foot at a time off each end until you find it but who knows how long the cord will be when you're done.

Lou Manglass

 

[Walkers]

Connect each end bare wire to your continuity tester, then wiggle the wire in about 6” increments. Should hear the beeping if the open wires wiggle and touch each other. Generally you will find a small cut in the insulation. Biggest culprit in my shop is something heavy got dropped on it. Could be someone drove over it too.

 

[slow]

open ground should not make the end get hot. Electrical connections get hot for 2 reasons, loose connection or over current. I had an old Toro leaf blower that the extension cord end melted on, the female extension cord was old and worn out. That cord was 20 years old and was thrown away.

 

[samss]

What's the extension cord gauge and length? How many watts for the blower?

 

[Stuart in MN]

open ground should not make the end get hot. Electrical connections get hot for 2 reasons, loose connection or over current.

Agreed. Either a loose connection or overcurrent, and in this case it sounds like a loose connection. That could either be where the cord connects to the socket (assuming there's a screw terminal and it's not a molded end) or where the prongs plug into the socket.

 

[eejack]

< nevermind reading fail >

 

[kaffine]

Use an ohm meter and check each wire. Also check each wire to the others particularly hot to ground. I would really be surprised if the hot shorted to ground with enough resistance not to trip a breaker.

To find the open visual inspection is the easiest. If that doesn't work then a tone set (tone generator and inductive pickup) would be my next option. Stretch the cord out hook the generator up to the ground and then follow with the inductive pickup looked to see where it stops detecting the signal. The other option is if you have access to an Xray screening machine.

 

[wyliesdiesels]

The ground terminal is not used during normal operation and most yard tools are double insulated so they dont even have a ground pin on their plug. As said above, an open ground in the cord will not make the plug hot.

 

[66cj225]

Cord has demonstrated a problem. Cord = Junk

 

[sparky 1971]

Once upon a time I had a GB receptacle tester. When it told me there was an open ground, what it really meant was reversed polarity, so you may want to verify that too.

 

[theoldwizard1]

I was renting a lake front house from some very nice people. The outdoor cord in the garage had 3 or 4poorly repaired whacks from a hedge trimmer. I could not stand looking at them think that this nice lady might get shocked. I took them apart and "did them up right !"

 

[Jeepster04]

^speaking of hedge trimmers, I just cut a cord clean in two the other day... Second time on that particular cord.. Its now the dedicated hedge trimmer cord.

Those things kinda scare me, they would take a finger clean off.

 

[theoldwizard1]

Those things kinda scare me, they would take a finger clean off.

Think of the CARNAGE a chain saw can cause !

The most dangerous thing is a full chain saw in the hands of an inexperienced operator !!

 

[Fly YX]

Just get new Extension cords why take a chance or just go cordless

 

[yatg]

^speaking of hedge trimmers, I just cut a cord clean in two the other day... Second time on that particular cord.. Its now the dedicated hedge trimmer cord.

Those things kinda scare me, they would take a finger clean off.

A Trimmer mower can take your whole arm off.