For the

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What are main distortions and how to reduce them?

Example: An electrical unit was connected to the mains via a plastic mainsocket ledge??? and a 10 meter cable connected to the wall socket

A very typical mains distortion was simulated with a burst generator. Bursts are similar to the ones caused by contact bounce in mains switches, pulses from mains circuit breaker fuses or motors , relays, arcing from switches in fridges, drilling machines etc.

What are busts? Bursts are very short time overvoltage transients in the range of 1/1000 to more than 1/100 sec. The peaks consist of something like RF signals which reach up to some MHz, – quite similiar to the time rates of computers. Burst distortions move along conductors all around the main network in buildings, – sometimes even between them. Beside from this they are radiated because main cables work »very good« as antennas [transmitted distortions].

In our example we used a burst of 1/1000 sec and 1.500 volt peak which simulates a quite normal day by day situation.

Fig 1 The graph show the main voltages of about 220 volts – it doesn't look like a clean sine wave!, – plus a burst of 1500 volt and 5kHz spike frequency, measured via a 10 meter long main cable.




Fig 2 This figure show the same main voltages plus bust measured via a cicable PC3+1EMC main cable of the same length.




Fig 3 Another time the same graphs but zoomed: distortion caused by a burst measured via a 10 meter standard main cable.




Fig 4 Again the improvement of a cicable PC3+1EMC main cable zoomed. The distortion is nearly 50% reduced!

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