
Cable-length and cross-section: The frequency converter
has been tested with a given length of cable and a given
cross-section of that cable. If the cross-section is increased,
the cable capacitance - and thus the leakage current - may
increase, and the cable length must be reduced
correspondingly. Keep the motor cable as short as possible
to reduce the noise level and leakage currents.
Switching frequency: When frequency converters are used
together with Sine-wave filters to reduce the acoustic
noise from a motor, the switching frequency must be set
according to the Sine-wave filter instruction in
14-01 Switching Frequency
.
1.
Fasten decoupling plate to the bottom of the
frequency converter with screws and washers
from the accessory bag.
2.
Attach motor cable to terminals 96 (U), 97 (V), 98
(W).
3.
Connect to earth connection (terminal 99) on
decoupling plate with screws from the accessory
bag.
4.
Insert plug connectors 96 (U), 97 (V), 98 (W) (up
to 7.5 kW) and motor cable to terminals labelled
MOTOR.
5.
Fasten screened cable to decoupling plate with
screws and washers from the accessory bag.
All types of three-phase asynchronous standard motors can
be connected to the frequency converter. Normally, small
motors are star-connected (230/400 V, Y). Large motors are
normally delta-connected (400/690 V,
Δ
). Refer to the
motor name plate for correct connection mode and
voltage.
MOTOR
MOTOR
U V W
99
130B
T302.12
Illustration 8.7 Motor connection for A1, A2 and A3
Electrical Installation
FC 300 Design Guide
MG.33.BD.02 - VLT
®
is a registered Danfoss trademark
161
8
8