14
Digidrive SK Getting Started Guide
www.leroy-somer.com
Issue Number: d
3 phase 200V drives
8mA AC at 230V, 50Hz (proportional to supply voltage and frequency)
3 phase 400V drives
10.5mA AC at 415V, 50Hz (proportional to supply voltage and frequency)
With internal EMC filter removed
<1mA
4.2.1
Use of earth (ground) leakage circuit breakers (ELCB) / residual current
device (RCD)
There are three common types of ELCB/RCD:
Type AC
- detects AC fault currents
Type A
- detects AC and pulsating DC fault currents (provided the DC current
reaches zero at least once every half cycle)
Type B
- detects AC, pulsating DC and smooth DC fault currents
•
Type AC should never be used with drives
•
Type A can only be used with single phase drives
•
Type B must be used with three phase drives
4.3
EMC
4.3.1
Internal EMC filter
It is recommended that the internal EMC filter is kept in place unless there is a specific
reason for removing it.
If the drive is to be used on an IT supply, then the filter must be removed.
The internal EMC filter reduces radio-frequency emissions into the mains supply. Where
the motor cable is short, it permits the requirements of EN61800-3 to be met for the
second environment.
For longer motor cables, the filter continues to provide a useful reduction in emission
level, and when used with any length of shielded 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 is unacceptable or
the above conditions are true.
The above leakage currents are just the leakage currents of the drive with the internal EMC
filter connected and do not take into account any leakage currents of the motor or motor cable.
NOTE
In both cases, there is an internal voltage surge suppression device connected to
ground. Under normal circumstances, this carries negligible current.
NOTE
When the internal EMC filter is fitted, the leakage current is high. In this case, a
permanent fixed ground connection must be provided using two independent conductors
each with a cross-section equal to or exceeding that of the supply conductors. The drive
is provided with two ground terminals to facilitate this. The purpose is to prevent a safety
hazard occurring if a connection is lost.
WARNING
