Motor Connection
NOTE
Motor cable must be shielded/arm-
ored. The use of an unshielded/un-
armored cable is against EMC require-
ments. Use a shielded/armored motor
cable to comply with EMC emission
specifications. For more information,
see
EMC specifications
in the
VLT
®
Au-
tomationDrive FC 300 Design Guide
.
See the General Specifications section for the cor-
rect dimensioning of the motor cable cross-sec-
tion and length.
Shielding of cables:
Avoid installation with twis-
ted shield ends (pigtails). If it is necessary to
break the shield to install a motor isolator or mo-
tor contactor, the shield must be continued at the
lowest possible HF impedance.
Connect the motor cable shield to both the FC 300
decoupling plate and the motor's metal housing.
Make the shield 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 shield to install a mo-
tor isolator or motor relay, the shield must be
continued with the lowest possible HF impedance.
Cable-length and cross-section:
The adjusta-
ble frequency drive has been tested with a given
length and cross-section of that cable. If the
cross-section is increased, the cable capacitance -
and thus the leakage current - may increase,
thereby requiring the cable length to be reduced
correspondingly. Keep the motor cable as short as
possible to reduce the noise level and leakage cur-
rents.
Switching frequency:
When adjustable fre-
quency drives are used together with LC filters to
reduce the acoustic noise from a motor, the
switching frequency must be set according to the
LC filter instructions in Par. 14-01.
1.
Fasten decoupling plate to the bottom of
the 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 ground connection (terminal
99) on decoupling plate with screws from
the accessory bag.
4.
Insert plug connectors 96 (U), 97 (V), 98
(W) (up to 10 hp [7.5 kW]) and motor ca-
ble to terminals labeled MOTOR.
5.
Fasten shielded cable to the decoupling
plate with screws and washers from the
accessory bag.
Motor connection for A1, A2 and A3
VLT
®
AutomationDrive FC 300 Instruction Manual
How
to
Install
22
MG.33.A8.22 - VLT
®
is a registered Danfoss trademark.
