ABB IRC5P, Руководство по эксплуатации продукта, Страница: 214 / 220

10 Reference Information
10.3 Bonding Information
214 3HNA009834-001 en Rev.06 Product Manual, Control Cabinet IRC5P
Alternative Bonding
Methods
The following shows 3 examples on how the signal cable screens can be bonded:
Figure 90 Bonding examples
Example 1
Where a good bonding is available on all units, the best shielding is obtained by
bonding all screens at both ends on all units.
Example 2
If a solid bonding connection can not be provided e.g. for an external unit such as a
communication node, I/O unit, PLC or a sensor etc., the screen for the cable must
not be bonded at the unit without a good bonding connection. This situation is
shown in Figure 90 , example 2. If the cable is routed and terminated in a junction
box etc. and the junction box has a good bonding connection, the screens for both
cables must be bonded at this point.
Example 3
If the cable is terminated in a junction box or other unit where a good bonding is not
available, the screens of the 2 cables must be connected as shown in Figure 90 ,
example 3, but not connected to the chassis of the unit.
Junction box etc. External unit
Example 1
Ground all screens
when a good ground
connection is available
Control cabinet
Example 2
Do not ground screen
at end where good
ground is not available
Example 3
Interconnect screens
but do not connect to
ground in external units
when good ground is not
available
Interconnect screens at
this point if single cable
cannot be used
Example on noise
supression capacitor