NORD Drivesystems BU0750 User Manual
Page 21
BU 0750 GB-3311
Subject to technical amendments
21
Before connecting the device, the following must be observed:
1. Ensure that the voltage source provides the correct voltage and is suitable for the current required (see
Section 9 Technical data). In addition, care must be taken that suitable power switch with the specified
rated current range is installed between the voltage source and the frequency inverter.
2. Connect the mains voltage directly to the mains terminals L
1
- L
2
- L
3
and connect the earth (PE).
3. A four-core cable must be used to connect the motor. The cable must be connected to the motor terminals
U - V - W and the PE.
4. If shielded motor cables are used (recommended), the cable shielding must also be connected to a large
area of the metal screw fittings.
Note:
The use of shielded cables is essential in order to maintain the specified radio interference
suppression level. (See also Section 10.5 EMC limit value classes)
ATTENTION
Proper earthing must be ensured for
all metal covers. Otherwise the
frequency inverter must not be put
into operation (see illustration).
Usually, the line, motor and brake resistor cables are
connected first as their terminals are located on the
bottom circuit board. The various metric screw
fittings on the underside of the device are used as
cable glands (see 2.9.7 Cable Glands)
NOTE
If using certain wire end sleeves are used, the maximum cross-section which can be connected can
be reduced.
NOTE
If synchronous machines are connected or several motors are connected in parallel, the
frequency inverter must be operated with linear voltage/frequency characteristic curves,
P211 = 0 and P212 = 0.
Control terminal bar
Mains/motor/resistance
connections