![ABB NMBA-01 Скачать руководство пользователя страница 19](http://html.mh-extra.com/html/abb/nmba-01/nmba-01_installation-and-startup-manual_2753019.webp)
Chapter 4 – Electrical Installation
NMBA-01 Installation and Start-up Guide
4-3
Earthing
The NMBA-01 module earth is connected to the rail onto which the
module is mounted. If the rail is fastened to an earthed metallic
assembly plate, the module is automatically earthed, and no external
earthing wire is needed. If the rail is fastened to a base that is not
earthed, the rail must be connected to the nearest earthing terminal.
However, the earthing wire should not be connected to the same
terminal as the power cable screens. (See page 3-1.)
In the NMBA-01 module there are several built-in earthing terminals
(see
Figure 4-3 and Figure 4-4 ):
•
The PE terminal is internally connected to the NMBA-01 module
earth. Normally, no external wires need to be connected to this
terminal.
•
The SH terminal is internally connected to the NMBA-01 module
earth. The SH terminal is normally used for earthing the Modbus
cable shield if there is no other station at which the cable shield is
directly earthed.
•
The SHF terminal is internally connected to the NMBA-01 module
earth via an RC filter. The SHF terminal is typically used for earthing
the Modbus cable shield.
•
The DG terminal is isolated from the NMBA-01 module earth. This
terminal is used for connecting the third conductor of the bus cable.
The third conductor – Data Ground – offers a common reference or
comparison potential to all modules on the bus.
Note: The use of Data Ground is recommended as it improves noise
immunity. See
Figure 4-3 and Figure 4-4.
efesotomasyon.com - Control Techniques,emerson,saftronics -ac drive-servo motor