Product Manual

CU331SP variable frequency drive
SQ, SQE, CU 331, and SP
10
46
Connecting the signal relays
As a precaution, signal cables must be separated from
other groups by reinforced insulation in their entire
lengths.
Fig. 42 Terminals for signal relays (normal state, not
activated)
Signal relay
The signal relays on the CU331SP are predefined as
follows:
Relay 1: Pump running
Relay 2: Alarm
Fig. 43 Terminals for relay connection
EMC-correct installation
This section gives guidelines for good practice when
installing the CU331SP. 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. 44.
• Avoid terminating the screen by twisting the ends.
See fig. 45. Use cable clamps or EMC screwed
cable entries instead.
• Connect the screen to frame at both ends for both
motor and signal cables. If the controller has no
cable clamps, connect only the screen to the
CU331SP.
• 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 minimize leakage currents.
• Screws for frame 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. 44 Example of stripped cable with screen
Fig. 45 Do not twist the screen ends
TM03 8801 2507
Terminal Function
C 1 C 2 Common
NO 1 NO 2 Normally open contact
NC 1 NC 2 Normally closed contact
TM03 9008 2807
C 1
NC 1
NO 1
NC 2
NO 2
C2
TM02 1325 0901TM03 8812 2507