Motor Connection - Danfoss VLT AutomationDrive FC 300 Operating Instructions Manual

Motor Connection

NB!
Motor cable must be screened/arm-
oured. If an unscreened/unarmoured
cable is used, some EMC requirements
are not complied with. Use a screened/
armoured motor cable to comply with
EMC emission specifications. For more
information, see EMC specifications in
®
the VLT AutomationDrive FC 300 De-
sign Guide.
See section General Specifications for correct di-
mensioning of motor cable cross-section and
length.
Screening of cables:
twisted screen ends (pigtails). They spoil the
screening effect at higher frequencies. If it is nec-
essary to break the screen to install a motor iso-
lator or motor contactor, the screen must be
continued at the lowest possible HF impedance.
Connect the motor cable screen to both the de-
coupling plate of the FC 300 and to the metal
housing of the motor.
Make the screen connections with the largest pos-
sible surface area (cable clamp). This is done by
using the supplied installation devices in the FC
300.
If it is necessary to split the screen to install a
motor isolator or motor relay, the screen must be
continued with the lowest possible HF impedance.
Cable-length and cross-section:
cy 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 capaci-
tance - and thus the leakage current - may in-
crease, and the cable length must be reduced
correspondingly. Keep the motor cable as short as
possible to reduce the noise level and leakage cur-
rents.
Switching frequency: When frequency convert-
ers are used together with LC filters to reduce the
acoustic noise from a motor, the switching fre-
quency must be set according to the LC filter in-
struction in Par. 14-01.
22
How to Install
Avoid installation with
The frequen-
MG.33.A8.02 - VLT is a registered Danfoss trademark
1. Fasten decoupling plate to the bottom of
FC 300 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 acces-
sory bag.
Motor connection for A1, A2 and A3