Can an unused cable break in?

Voltage is a differential. It is in other words measured between two things. Across a circuit. Without which (a complete circuit) there is no voltage, no amperage, no capacitance, no nothing. (Try buying a meter that can read voltage, resistance, capacitance, inductance- you name it - without being connected to anything.)

You don’t need a closed circuit to have a difference of potential, voltage.
If you connect a pair of wires to a source at the end or anywhere along the pair of wires the difference of potential exists.

Install a switch in series with one of the lines. When the switch is open the difference of potential will be broken, opened, only on the load side of the switch. Ahead of the switch the potential is not affected. The potential still exists.

The Cyrus CD transport Power supply is connected directly to the AC mains. Not switched. The switch on the face of Cyrus CD transport is down stream of the power supply. The switch does not kill power to the power supply.

Plugging a regular power cord into a wall outlet with nothing (no load) connected to it will do nothing for burn-in of the cable. Does a difference of potential exist at the IEC connector if the wall outlet is live? Yes. But without a connected load there is not a current. No energy is being consumed.
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@jea48 -   "You don’t need a closed circuit to have a difference of potential, voltage.
If you connect a pair of wires to a source at the end or anywhere along the pair of wires the difference of potential exists."                                                                                                                         Isn't that why these work?       https://www.fluke.com/en-us/product/electrical-testing/basic-testers/fluke-2ac 

No, that isn't why it works. And it doesn't measure voltage, but merely detects it. No offense but mainly what I detect is word games. Someone says something and whether totally correct or incorrect means nothing but an opportunity to interject.   

Nothing burns in without current. End of story.

rodman999995,038 posts

06-13-2021
10:25am

@jea48 - "You don’t need a closed circuit to have a difference of potential, voltage.
If you connect a pair of wires to a source at the end or anywhere along the pair of wires the difference of potential exists."
Isn’t that why these work? https://www.fluke.com/en-us/product/electrical-testing/basic-testers/fluke-2ac

Yes. Though the no contact voltage tester actually is measuring the electric field around the Hot Ungrounded conductor. The tester works on capacitance. When you hold the tester in your hand your body is ground. You can be totally insulated from an EGC, (Equipment Grounded), object and the tester will still work.


https://voltstick.com/how-to-av/videos-and-blogs/how-does-voltstick-work
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"When you hold the tester in your hand your body is ground."                                               Been using those for decades and always believed that was the case.       Thanks for the confirmation/insight/link (filling in the blanks)!