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My question has to do with identifying the hot (black) and neutral (white) wires on the plug, when both wires are unmarked twisted copper? The other end of the cord (outlet) is well marked with white and black wires.

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    Just curious how one end of a cord is marked but the other is not? – Speedy Petey Jan 21 '15 at 12:46
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They make a tool called a continuity tester. These also come in the form of a meter product that can also measure voltage and current. You can pick these up at most auto parts stores or hardware stores for a relatively low price.

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To use the continuity tester, you would connect the clip to one of the known wires, and then touch the end of the probe to each of the unknown wires in turn. Which ever wire lets the bulb light up is the same wire as the known wire. Obviously make sure everything is unplugged from mains power before doing this.

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To use a multimeter for continuity testing you make sure that the cord/wiring that you are testing is not connected to any mains outlets. Then make sure the two test leads are plugged into the black COM jack and the red VOLT/OHM jack. Rotate the range selector to the lowest OHMs setting. Momentarily tough the two test lead ends together to verify the meter is working correctly. The meter should show a reading of near zero ohms. In the case of a meter like shown above a zero ohm reading will deflect the needle all the way to the right. Next step is to touch one of the test leads to one of the known wires. Then at the same time touch the other test lead to the unknown wire ends in turn. The one that causes the meter to show a reading near zero ohms (deflects the needle to the right) will be the same wire as the known wire.

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    To make this a better answer, you should explain how to utilize the multi-meter for the OP. It seems to me if they don't know what a multi-meter is, they'd also have no clue how to utilize one ... just a thought. – Pᴀᴜʟsᴛᴇʀ2 Jan 21 '15 at 13:03
  • OK I edited in the answer to show a description of how to use a multi-meter for continuity checking. Thanks to @sww1235 for adding the description of how to use the continuity tester. – Michael Karas Jan 22 '15 at 12:47

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