Power cable polarity test

Matrix black IECThe Power cable polarity test is essential and ensures your power cable will perform correctly. The IEC connection (shown in the picture) has three openings, which can be related to a triangle. The opening on the right for the Positive (or live) connection. The opening on the left is for the Neutral (or return). And, the opening in the middle is for the Earth (or ground) connection.

Power cable 

Polarity checkThe first item you must always check is the polarity of your mains connection. For example, the mains socket shown is an EU configuration. The test shows the positive power on the left-hand side. So if you were to connect your power cable and check at the IEC end, you would have a problem. The IEC end would show positive on the left, and this is incorrect. In many cases, a house has suffered from faulty wiring. And you must always check the polarity and adjust accordingly.

Polarity test

Correct polarity

The picture on the right shows the power connection in another room in the same house. And this time, the polarity is correct, as the red is on the right-hand side. And when the power cable is connected and the IEC plug checked, it will be correct. Never assume every room in your house is wired in the same manner because you could be surprised at the things I have found when testing cables!

Weakest link

The power cable is an essential item in the audio chain, but please be advised your audio system can only be as good as the weakest link. And, I want to explain the basic steps for you to check your power cable polarity. You may be aware of the importance of what a suitable power cable can do for your audio system. And, you are maybe aware of how to check your power cable. But, if you are not, please follow these instructions, and you will undoubtedly be aware of the sonic improvement.


Power cable polarity To test your power cable polarity, you need a one contact neon test light (or an electricians test screwdriver), as it is known. 

A low-cost type of test lamp only contacts one side of the circuit under test and relies on stray capacitance and current passing through the user’s body to complete the circuit. The device may have the form of a screwdriver. The tester touches the conductor under test. A neon lamp takes minimal current lighting, and thus can use the user’s body capacitance to earth ground to complete the circuit.

Minimal cost

Power cable polarity testScrewdriver-type test lamps are very inexpensive but cannot meet the construction requirements of UK GS 38. If the shaft is exposed, a shock hazard to the user exists, and the internal construction of the tester does not protect against short-circuit faults.

Failure of the resistor and lamp series network can put the user in direct metallic contact with the circuit under test. For example, water trapped inside the screwdriver may allow enough leakage current to shock the user. Even if an internal short does not electrocute the user, the resulting electric shock may result in a fall or other injury. The lamp does not indicate the strike voltage of the neon lamp and so cannot detect certain hazardous leakage conditions since it relies on capacitance to complete the circuit.

EU  power 

IEC connection

When testing the IEC connection of your power cable, the screwdriver must be in the right-hand opening. And, you must constantly push firmly to ensure good contact. Also, you must place your thumb over the mother end of the test screwdriver to complete the test circuit.

I always say, ‘Red to the right’, and If you have a positive power to the right-hand opening, the neon will illuminate, and you will see the red glow of the neon in the testing screwdriver. If you do not see the red light, it means you must rotate the power cable 180 degrees and test again. If you are using the US or UK plug, you will have to reconfigure the plug wiring to make it positive on the right at the IEC plug.


The phase is a not to be underestimated factor for the resulting sound. But, again, assuming the manufacturers of the cable and component have followed the standards. In that case, the IEC end of a power cable and the male connector in the element should already have a matched pinout connection. And you must adjust every power cable in your audio system to have the exact alignment.

Finally, please note that power cables can affect the overall audio setup, even when they are only connected to the audio system’s extension block and not to any receiving component. 

If you have enjoyed reading ‘Power cable polarity test’, please share with friends and colleagues – thank you.

Perkune – Best budget Audiophile Cables

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.