Kenmore Elite 31150 Power cord gets warm

[charlestek]

Just purchase a used Kenmore Elite 31150 from ebay, and received it today.
Appears to work well. However, the power cord gets mildly warm after short use of the vacuum. I used a Kill-A-Watt and the vacuum draws about 11.5amps RMS, close to its rated draw of 12 amps. I did note that the outlet in the living room is nominally 122 volts rms and drops to about 118 volts rms when the vacuum is running which means that the wiring to the outlet is not as good as it should be.

Otherwise, the fact that the vacuum cord gets warm implies that for its long length that it is using a wire gauge smaller than it should be. In fact looking at the diameter of the cord, I would guess that the wire gauge is 16, rather than at least 14 gauge, which would be proper. The fact that the kill-a-watt shows that the current draw is around what it should be makes it appear that their are no shorts or extreme issues inside the vacuum cleaner.

I just wanted to ask if anyone has seen this in the same model or similar vacuum.

If I was really ambitious, I could try to check the voltage inside the vacuum cleaner as that would tell me how much voltage drop there was in the cord and how much power/heat is being wasted in the cord. Haven't gone there yet.

I am checking the Sears warranty if it exists, and I also purchased a square trade warranty. However my guess is that Sears is cheaping out on the wire in the vacuum cord.

 

[charlestek]

The cord is 17 gauge

I just checked the imprinting on the power cord, it is a lousy 17 gauge cord which is way too thin for 12 amps and a fairly long cord. I tried it on a 20 amp outlet in the house and the cord heats less but is still warm near the outlet connector.

I think I do have a 14 gauge cord I put on an old sharp twin energy vacuum I had whose brushes are shot. I could wire that in, but it is hard to tell how complicated the innards will be. It appears I would have to unscrew a bunch of phillips screws in the top of the lower handle and pull that apart to get at the cords termination inside the machine.

 

[fan-of-fans]

If it is just mildly warm, it is fine. I have had cords on several vacuums get fairly warm near the plug, even older ones did it.

 

[charlestek]

Thank you

Yes, it gets less warm if I'm running off a 20amp breakered outlet then the 15 amp circuit in the living room that was exhibiting the voltage drop from a 12 amp load.
This is a rented house so I'm not about to change the wiring.

Actually I am an electrical engineer by degree, so I should know what I'm talking about, though I've done software for more than a decade.

However, it could stand to have a 14 gauge cord and a heavy duty plug. Does anyone know if it is possible to get service manuals for a fairly new Kenmore Vacuum cleaner?

It will have to wait till I get ambitious and want to disassemble the top of the vacuum and swap to a 14 gauge cord.