PLC | mask cable connection? One side, both sides of the ground PART-2

[http://vkinngworld.blogspot.com/]


In the previous article, one might think,
Is to one side seems to be grounded!!


In actual fact, you should look at both sides of the equipment is grounded and fixed!!


If the wiring between the motor with the controller,mask cable(ground line) will  take 1  sides ,
Because the motor has a ground with the controller.


But if it is between the controller with external sensor,
mask cable(ground line) will  take 2 sides,
Because the sensor is not grounded, a ground controller.


So mask cable, isolation
To take a side or2 side ground, depending on the situation,
Not every case is appropriate.

PLC | mask cable connection? One side, both sides of the ground

[http://vkinngworld.blogspot.com/]


Are usually popular only take one side,
Can not both sides to ground.


Reason? WHY?
Check a lot of pages are finding out why.


I summarized this principle should be!!


Ground controllers, ground with other big power line can not be connected in series,
To be connected with the star-ground,
Is the fear of series equipment to the back-ground line,
Is not a zero potential.


So ☆ ground terminals each device will have different potential ☆


And because: each device ground terminals, have different potential


So: When the mask wire to ground connection on both sides, it will have a great current (magnetic field),
But affects the inside of the signal line.


V = the potential difference on both sides of the ground (assuming = 10V)
R = resistance of shielded cable (less than 10 ohms)

A = V / R = 10V/10 ohms = 1A

PLC|屏蔽線、隔離網接法?單邊、兩邊接地 PART-2

[http://vkinngworld.blogspot.com/]

在上一篇當中，也許有人會覺得，
好像應該就是要單邊接地!!

其實不然，應該要看兩邊的設備是否有接地而定!!

如果是馬達跟控制器之間的配線，
隔離網就只要接單邊，
因為馬達跟控制器都有接地。

但如果是控制器跟外部的sensor之間，
隔離網就要接雙邊，
因為sensor並沒有接地，控制器有接地。

所以屏蔽線、隔離網接單邊or兩邊接地，要看情形，
不是每種情形都合適。