17
13.6 EMC-correct installation
This section gives guidelines for good practice when installing the
CUE. Follow these guidelines to meet 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. See fig. 38.
•
Avoid terminating the screen by twisting the ends. See fig. 39.
Use cable clamps or EMC screwed cable entries instead.
•
Connect the screen to ground at both ends for both motor and
signal cables. See fig. 40. If the controller has no cable
clamps, connect only the screen to the CUE. See fig. 41.
•
Avoid unscreened motor and signal cables in electrical
cabinets with variable frequency drives.
•
Make the motor cable as short as possible in applications
without output filter to limit the noise level and minimise
leakage currents.
•
Screws for ground connections must always be tightened
whether a cable is connected or not.
•
Keep main 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.
Fig. 38
Example of stripped cable with screen
Fig. 39
Do not twist the screen ends
Fig. 40
Example of connection of a 3-conductor bus cable with
screen connected at both ends
Fig. 41
Example of connection of a 3-conductor bus cable with
screen connected at the CUE (controller with no cable
clamps)
13.7 RFI filters
To meet the EMC requirements, the CUE comes with the
following types of built-in radio frequency interference filter (RFI):
* Single-phase input - three-phase output.
Description of RFI filter types
RFI filter types are according to EN 61800-3.
13.7.1 Equipment of category C3
•
This type of power drive system (PDS) is not intended to be
used on a low-voltage public network which supplies domestic
premises.
•
Radio frequency interference is expected if used on such a
network.
13.8 Output filters
Output filters are used for reducing the voltage stress on the
motor windings and the stress on the motor insulation system as
well as for decreasing acoustic noise from the variable-
frequency-driven motor.
Two types of output filter are available as accessories for the
CUE:
•
dU/dt filters
•
sine-wave filters.
Use of output filters
The lengths stated apply to the motor cable.
T
M
02 1
325 0
901
T
M
03
8812
250
7
T
M
03
8732
240
7
CUE
Controller
T
M
03 87
31 240
7
Voltage
Typical shaft power P2
RFI filter type
1 x 200-240 V*
1.5 - 10 hp
C1
3 x 200-240 V
1 - 60 hp
C1
3 x 380-500 V
0.75 - 125 hp
C1
3 x 525-600 V
1 - 10 hp
C3
3 x 525-690 V
15 - 125 hp
C3
C1: For use in domestic areas
C3:
For use in industrial areas with own low-voltage
transformer
Pump type
Typical shaft
power P2
dU/dt
filter [ft]
Sine-wave
filter [ft]
SP, BM, BMB with
380 V motor and up
Up to 10 hp
–
0-1000
15 hp and up
0-500
500-1000
Other pumps, noise
reduction
Up to 10 hp
–
0-1000
15 hp and up
0-500
500-1000
Other pumps, higher
noise reduction
Up to 10 hp
–
0-1000
15 hp and up
–
0-1000
Pumps with 690 V
motor
All
–
0-1000
CUE
Controller
Grundfos.bk Page 17 Friday, July 30, 2010 10:10 PM
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Grundf
os CU
E