User guide

22 Unidrive SP Short Form Guide
www.controltechniques.com Issue Number: 2
3.8 EMC filters
3.8.1 Internal filter
It is recommended that the internal EMC filter be kept in place unless there is a specific
reason for removing it.
If the drive is part of a regen system or is a Unidrive SP size 3 to 6 on an IT supply then
the internal EMC filter must be removed.
The internal EMC filter reduces radio-frequency emission into the line power supply.
Where the motor cable is short, it permits the requirements of EN61800-3:2004 to be
met for the second environment - for further information see the Unidrive SP User Guide
on the CD Rom supplied with the drive. For longer motor cables the filter continues to
provide a useful reduction in emission level, and when used with any length of shielded
motor cable up to the limit for the drive, it is unlikely that nearby industrial equipment will
be disturbed. It is recommended that the filter be used in all applications unless the
ground leakage current (on 400V, 50Hz supply) of 28mA for sizes 0 to 3 and 56mA for
sizes 4 to 6 is unacceptable or the above conditions are true.
Figure 3-5 Removal of Size 0 internal EMC filter
Figure 3-6 Removal of Size 1 to 3 internal EMC filters
2
2
1
3
4