Installation Of Motor Cables; Connection Of Motor; Direction Of Motor Rotation - Danfoss VLT 5000 Series Instruction Manual

Installation of motor cables

NOTE
If an unscreened cable is used, some
EMC requirements are not complied with.
If the EMC specifications regarding emis-
sion are to be complied with, the motor
cable must be screened, unless otherwise
stated for the RFI filter in question. It is
important to keep the motor cable as short
as possible so as to reduce the noise level
and leakage currents to a minimum.
The motor cable screen must be connec-
ted to the metal cabinet of the adjustable
frequency drive and to the metal cabinet
of the motor. The screen connections are
to be made with the biggest possible sur-
face (cable clamp). This is enabled by
different installation devices in the differ-
ent adjustable frequency drives.
Installation with twisted screen ends (pigtails) is to be
avoided, since these spoil the screening effect at high-
er frequencies.
If it is necessary to break the screen to install a motor
isolator or motor contactor, the screen must be con-
tinued at the lowest possible HF impedance.
The adjustable frequency drive 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 ca-
pacitance — and thus the leakage current — increa-
ses, and the cable length must be reduced corre-
spondingly.

Connection of motor

All types of 3-phased asynchronous standard motors
can be used with the VLT 5000 Series.
Normally, small motors are star-connected (200/400
V, /Y).
Large motors are delta-connected (400/690 V, /Y).
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VLT 5000 Series

Direction of motor rotation

The factory setting is for clockwise rotation with the
frequency transformer output connected as follows.
Terminal 96 connected to U-phase
Terminal 97 connected to V-phase
Terminal 98 connected to W-phase
Thedirection of motor rotation can be changed by
switching two phases in the motor cable.
Parallel coupling of motors
Adjustable frequency drives are able to control several
motors connected in parallel. If the motors are to have
different rpm values, the motors must have different
rated rpm values. Motor rpm is changed simultane-
ously, which means that the ratio between the rated
rpm values is maintained across the range.
The total current consumption of the motors is not to
exceed the maximum rated output current I
adjustable frequency drive.
MG.51.C5.22 - VLT is a registered Danfoss trademark.
for the
VLT,N