Electrical Basics Revisited

[RockyBoy]

May be the polarity means like below picture. If you connect the wrong point in the 3-pin plug, even though you have switch off the circuit, the load will still be live. However, our socket outlet has its own switch so it would be still safe.

But now, if the L & N is reverse, the load will also receive the 'reversed' polarity, and current leakage would happened. Those 2-pin plugs normally have loads that can accept either direction of the L&N input. Also, by right AC circuit has no polarity because it is sinesoidal alternating wave running at 50 or 60 hertz. So the L can be -ve and +ve at 50 hertz cycle.

For DC circuit, the +ve remains at +ve and -ve remains at -ve, where polarity is important for running of the load.

[Gouldian]

Wow, thanks for the explaination!

[reeftask]

May be the polarity means like below picture. If you connect the wrong point in the 3-pin plug, even though you have switch off the circuit, the load will still be live. However, our socket outlet has its own switch so it would be still safe.

But now, if the L & N is reverse, the load will also receive the 'reversed' polarity, and current leakage would happened. Those 2-pin plugs normally have loads that can accept either direction of the L&N input. Also, by right AC circuit has no polarity because it is sinesoidal alternating wave running at 50 or 60 hertz. So the L can be -ve and +ve at 50 hertz cycle.

For DC circuit, the +ve remains at +ve and -ve remains at -ve, where polarity is important for running of the load.

As above drawing, after the switch is on, there will still have leakage.

If there is leakage, the product is lousy.

Some new electrical/electronic items will have leakages because of bad designs/insulations.

[DaY]

Can refer to previous posting on how to DIY a grounding probe to remove the stray electricity.

http://www.sgreefclub.com/forum/index.php?...=11294&hl=earth

[reeftask]

Can refer to previous posting on how to DIY a grounding probe to remove the stray electricity.

http://www.sgreefclub.com/forum/index.php?...=11294&hl=earth

Very very low amps below 0.3mA leak oK but if more, it will trip your ELCB.