Ground Connections - Bosch REXROTH EFC 3600 Instruction Manual

DOK-RCON01-REX*F*UL***-IN01-EN-P
Rexroth Frequency Converters
Twisted Wires
Twist unshielded wires belonging to the same circuit (feeder and return cable) or keep
the surface between feeder and return cable as small as possible. Wires that are not
used have to be grounded at both ends.
Lines of Measuring Systems
Lines of measuring systems must be shielded. Connect the shield to ground at both
ends and over the largest possible surface area. The shield may not be interrupted,
e.g. using intermediate terminals.
Digital Signal Lines
Ground the shields of digital signal lines at both ends (transmitter and receiver) over
the largest possible surface area and with low impedance.
Analog Signal Lines
Ground the shields of analog signal lines at one end (transmitter or receiver) over the
largest possible surface area and with low impedance. This avoids low-frequency inter‐
ference current (in the mains frequency range) on the shield.
Connecting the Mains Choke
Keep connection lines of the mains choke at the drive controller as short as possible
and twist them.
Installing the Motor Power Cable
● Use shielded motor power cables or run motor power cables in a shielded duct
● Use the shortest possible motor power cables
● Ground shield of motor power cable at both ends over the largest possible surface
area to establish a good electrical connection
● Run motor lines in shielded form inside the control cabinet
● Do not use any steel-shielded lines
● The shield of the motor power cable mustn't be interrupted by mounted components,
such as output chokes, sine filters or motor filters
6.2

Ground Connections

Housing and Mounting Plate
By means of appropriate ground connections, it is possible to avoid the emission of in‐
terference, because interference is discharged to ground on the shortest possible way.
Ground connections of the metal housings of EMC-critical components (such as filters,
devices of the drive system, connection points of the cable shields, devices with micro‐
processor and switching power supply units) have to be well contacted over a large
surface area. This also applies to all screw connections between mounting plate and
control cabinet wall and to the mounting of a ground bus to the mounting plate.
EMC Measures for Design and Installation
Bosch Rexroth AG
55/65