TMA06789
TM006789
ELCB/RCD
The circuit breaker is type B.
The total leakage current of all the electrical equipment in the
installation must be taken into account.
The leakage current of CUE in normal operation can be seen in the
electrical data section.
During startup and in asymmetrical supply systems, the leakage
current can be higher than normal and may cause the ELCB/RCD
to trip.
Related information
6.1.4 Motor protection
The motor requires no external motor protection. CUE protects the
motor against thermal overloading and blocking.
6.1.5 Protection against overcurrent
CUE has an internal overcurrent protection for overload protection
on the motor output.
6.1.6 Protection against mains voltage transients
CUE is protected against mains voltage transients according to EN
61800-3, second environment.
6.2 EMC-correct installation
The motor cable must be screened for CUE to meet EMC
requirements.
This section provides guidelines for good practice when installing
CUE. Follow these guidelines to comply with EN 61800-3, first
environment.
•
Use only motor and signal cables with a braided metal screen in
applications without output filter.
•
There are no special requirements to supply cables, apart from
local requirements.
•
Leave the screen as close to the connecting terminals as
possible.
•
Avoid terminating the screen by twisting the ends. See the figure
below about not twisting the screen ends. Use cable clamps or
EMC screwed cable entries instead.
•
Connect the screen to frame at both ends for both motor and
signal cables. See the figure below with an example
of connection of a 3-conductor bus cable with screen connected
at both ends. If the controller has no cable clamps, connect only
the screen to the CUE cabinet. See the figure below with an
example of connection of a 3-conductor bus cable with screen
connected to CUE (controller with no cable clamps).
•
Avoid unscreened motor and signal cables in electrical cabinets
with frequency converters.
•
Make the motor cable as short as possible in applications
without output filter to limit the noise level and minimise leakage
currents.
•
Screws for frame connections must always be tightened
whether a cable is connected or not.
•
Keep mains cables, motor cables and signal cables separated in
the installation if possible.
Other installation methods may give similar EMC results if the
above guidelines for good practice are followed.
TM021325
Example of stripped cable with screen
TM038812
Do not twist the screen ends
1
2
TM038732
Example of connection of a 3-conductor bus cable with screen
connected at both ends
Pos.
Description
1
Controller
2
CUE
1
2
TM038731
Example of connection of a 3-conductor bus cable with screen
connected to CUE (controller with no cable clamps)
Pos.
Description
1
Controller
2
CUE
Related information
6.3 RFI filters
To meet the EMC requirements, CUE comes with the following
types of built-in radio-frequency interference filters (RFI).
9
English (GB)
