VLT
®
FCD Series
Installation
■
Connection of HAN 10E motor plug for T73
HAN 10E pin no 1 - Motor phase U
HAN 10E pin no 2 - Motor phase V
HAN 10E pin no 3 - Motor phase W
HAN 10E pin no 4 - Motor brake, see
Operating
Instructions MG.04.BX.YY
, terminal 122
HAN 10E pin no 5 - Motor brake, see
Operating
Instructions MG.04.BX.YY
, terminal 123
HAN 10E pin no 9 - Motor thermistor, see
Operating
Instructions MG.04.BX.YY
, terminal 31A
HAN 10E pin no 10 - Motor thermistor, see
Operating Instructions MG.04.BX.YY
, terminal 31B
PE = protective earth
■
Parallel connection of motors
The frequency converter is able to control several
motors connected in parallel. If the motors are
to have different rpm values, use motors with
different rated rpm values. Motor rpm is changed
simultaneously, 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
INV
for the frequency converter.
Problems may arise at the start and at low rpm
values if the motor sizes are widely different. This
is because the small motors
’
relatively high ohmic
resistance in the stator calls for a higher voltage
at the start and at low rpm values.
In systems with motors connected in parallel, the
electronic thermal relay (ETR) of the frequency
converter cannot be used as motor protection for
the individual motor. For this reason further motor
protection must be used, e.g. thermistors in each
motor (or an individual thermal relay).
NB!:
Parameter 107
Automatic motor tuning, AMT
cannot be used when motors are connected
in parallel. Parameter 101
Torque characteristic
must be set to
Special motor characteristics
[8]
when motors are connected in parallel.
■
Motor cables
See Technical data for correct dimensioning of motor
cable cross-section and length. Always comply with
national and local regulations on cable cross-section.
NB!:
If an unscreened/unarmoured cable is used,
some EMC requirements are not complied with,
see
EMC test results
in the Design Guide.
If the EMC specifications regarding emission are
to be complied with, the motor cable must be
screened/armoured, 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 connected to the metal cabinet
of the frequency converter and to the metal cabinet of
the motor. The screen connections are to be made
with the biggest possible surface area (cable clamp).
This is enabled by different installation devices in
different frequency converters. Mounting with twisted
screen ends (pigtails) is to be avoided, since these
spoil the screening effect at high frequencies. If it
is necessary to break the screen to install a motor
isolator or motor relay, the screen must be continued
at the lowest possible HF impedance.
■
Motor thermal protection
The electronic thermal relay in UL-approved frequency
converters has received the UL-approval for single
motor protection, when parameter 128
Motor thermal
protection
has been set for
ETR Trip
and parameter
105
Motor current, I
M, N
has been programmed to
the rated motor current (see motor nameplate).
MG.04.B7.02 - VLT is a registered Danfoss trademark
17
