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What type of power cord can I use to fix a coffee maker?

  1. Jun 12, 2015 #1
    Hello everybody, I am trying to replace a power cord from a CBTL coffee machine. The cord, which was accidentally cut, has the following description. svt 300v, 18 awg, 105C. I have tried different shops around LA to find the power cord, but the best I was able to find was svt, 300v, 18awg, 75C. The only difference is the temperature. In a different shop, I was able to find the same power cord (the one with 75c), but instead of svt, it says stj. Will the temperature rating really matter much if I use the one I was able to find? I would really appreciate your advice on how to fix this issue and explanation of why it would, or wouldn't work. Thanks in advance.
     
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  3. Jun 12, 2015 #2

    jim hardy

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  4. Jun 12, 2015 #3
    Thanks jim, I will read the article, but the power cord is a bit different. The one I need looks like the one the computers or monitors use. I think it's called a 3 end prong, I apologize if that is not the name.
     
  5. Jun 12, 2015 #4

    jim hardy

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    No apology , my mistake i assumed it was 2 conductor like mine.

    That should be a fairly common cord.
    Just i can't find insulation details at sites for Home Depot and Ace Hardware...

    here's a manufacturer's site
    http://www.kordking.com/products/stock-cords/3-conductor-stock.php
    he lists plenty of 105C cords in 18 gage.
    A good hardware store can order one for you
    CPE insulation is i think what you want.

    perhaps you'll find one in a thrift store... look for the 105C marking. Dont use low temperature cord . Where you splice, use 105C connectors .
     
  6. Jun 12, 2015 #5
    I will keep looking. Home dopot does not have anything higher than 16 awg, but i guess 16 awg won't hurt. The only downside there was the 75c temperature. I have been researching all night about the temperature part. I don't quite understand why it is very important. Does the temperature refer to the wires getting hot and then melting the plastic or does it refer to outside sources getting the cord hot?
     
  7. Jun 12, 2015 #6

    jim hardy

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    Inside a coffeemaker you'll find a very high temperature wire going from the heating elements to the power cord. It's insulated by white glass braid or some other high temperature covering. That's because the wiring is run physically close to both the boiler and the heating element underneath the carafe. Clearly both can reach boiling point of water plus a few degrees.
    So 105C wire for the power cord makes sense, the inside of the appliance could conceivably get to 100C.
    CPE is okay for excursions to 120C so should the coffeemaker be allowed to boil dry and overheat it won't melt the incoming insulation and go pyrotechnic.

    So - in your case i'd call the coffeemaker's internal heating elements 'outside sources' because they're outside the wire even though they're inside the device.
     
  8. Jun 12, 2015 #7
    Thanks for the explanation Jim, I have started to understand why it is important. I just have one more question relating to the same subject. When the coffee-maker pulls energy from the outlet, the power cord will get hot as well because of the current flowing through the cord, am i correct? If I am, how does this heat compare to the heating element inside the coffee-maker, are they at the same temperature?
     
  9. Jun 12, 2015 #8

    jim hardy

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    You can feel the cord get warm anywhere along its length. That's from current flowing through it as you said. That heat flows from the copper through the insulation to ambient(room temperature). It's a few degrees, enough to feel but not to burn you or melt insulation.

    The heating elements get to 212F plus a few degrees. That's hotter than the power cord by probably 112F.
    When you open the cofffeemaker to replace your cord, study the connections to those heaters. I usually find them spot-welded so they'll handle the heat,.
    The special high temperature wire i mentioned goes to the switch and thermostat controls for boiler and carafe heater, finally to the incoming power cord. Heat flows along wires just like current does, so you'll see considerable separation between the heating elements and the incoming cord.

    While you have it open, place yourself in the shoes of the designer.
    How did he arrange the internal wiring to keep heat away from the power cord?

    coffee-maker-18.jpg

    those red and blue wires will have a high temperature insulation probably braided glass fibers.

    This guy has rewired a coffeemaker with ordinary lampcord, which is dangerous. He should have transitioned to high temperature wire at the rear entry not at the front switch. Beware of internet advice....

    F0RMNS6GXUZEMA8.MEDIUM.jpg
     
  10. Jun 12, 2015 #9

    jim hardy

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    ps i'd use #16 if it'll go through the entry fitting . It'll run cooler.

    Last one i opened had Torx security screws, they have a dimple that keeps you from using an ordinary tool. Sears et al sell security Torx sets under $10 and they're worth having.

    Good luck, and don't set a trap like the guy in that photo above. Disasters always result from domino effect on seemingly little things..

    Above all have fun.
     
    Last edited: Jun 12, 2015
  11. Jun 12, 2015 #10

    Thank you so much Jim, I really appreciate your explanation. I understand a lot better the purpose of using certain types of electrical cords. Indeed the coffee-maker has a special type of screw near the power cord which I was able to remove it using a pair of pliers. I also made the opening a little bit bigger and I will attach a 16 AWG 300v 105C power cord that I was able to find at lowes. I am glad I became part of this community and certainly of having met you, you have made a great contribution to my knowledge about electrical cords and I really appreciate that, thank you!
     
  12. Jun 12, 2015 #11

    jim hardy

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    Thanks for the kind words, helps an old guy feel perhaps a teeny bit useful.

    I learn a lot here at PF. Great place.

    old jim
     
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