Bosch Rexroth EFC 3600 Operating Instructions Manual page 152

Bosch Rexroth AG
Electromagnetic Compatibility (EMC)
Evaluation criterion
Evaluation criterion
A
B
C
Fig.11-3: Evaluation criterion
11.1.3 Noise emission of the drive system
Causes of noise emission
Controlled variable-speed drives contain converters containing snappy semiconductors.
The advantage of modifying the speed with high precision is achieved by means of
pulse width modulation of the converter voltage. This can generate sinusoidal currents
with variable amplitude and frequency in the motor.
cause unwanted but physically unavoidable emission of interference voltage and
interference fields (wide band interference). The interference mainly is asymmetric
interference against ground.
The propagation of this interference strongly depends on:
● configuration of the connected drives
● number of the connected drives
● conditions of mounting
● site of installation
● radiation conditions
● wiring and installation
If the interference gets from the device to the connected lines in unfiltered form, these
lines can radiate the interference into the air (antenna effect). This applies to power
lines, too.
Limit values for line-based disturbances
According to IEC EN 61800-3 or CISPR 11 (corresponds to EN 55011), the limit values
in the table below are distinguished. For this documentation both standards are
combined in the limit value classes A2.1 to B1.
150/235
Explanation (abbreviated form from EN 61800-3)
Deviations within allowed range
Automatic recovery after interference
Switched off without automatic recovery. Device remains
undamaged
DOK-RCON03-EFC-3600***-IT01-EN-P
Rexroth Frequency Converter EFC 3600