Advantech ADAM-5560 user manual Normal Mode and Common Mode, Wire Impedance

B.2.3 Normal Mode and Common Mode

Have you ever tried to measure the voltage between a live circuit and a concrete floor? How about the voltage between neutral and a concrete floor? You will get non- sense values. ‘Hot’ and ‘Neutral’ are just relational signals: you will get 110VAC or 220VAC by measuring these signals. Normal mode and common mode just show you that the Frame Ground is the most important reference signal for all the systems and equipments.

Figure B.4 Normal and Common Modes

Ground-pin is longer than others, for first contact to power system and noise bypass.

Neutral-pin is broader than Live-pin, for reducing contact imped- ance.

B.2.4 Wire Impedance

Figure B.5 High Voltage Transmissions

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