MFC710/AcR - Section: 3. Installation of the frequency converter
3. Installation of the frequency converter
3.1. Connecting the power circuit
The MFC710 / AcR drive is typically powered by a 3x400V 50Hz three-phase network. We also offer versions
for other voltages (e.g. 3x500V, 3x690V). It should be noted that all parameters resulting from load currents
are given for the 3x400V power supply network. Fig.3.1, 3.2 and 3.3 show variants of high-current
connections - depending on the converter design. These diagrams replace the diagram in fig. 2.1 in the
MFC710 manual. The cable cross-sections and the type of line reactor should be selected depending on the
load current. To meet the requirements of the European Union Directive in the field of EMC electromagnetic
compatibility, a four-wire cable should be used in the screen, supplying the motor (three protective
conductor).The type of line chokes and protections is available from the manufacturer's representative.
If there is a need to use contactors between the converter and the motor, care should be taken to switch the
contactor off in a voltage free state when the converter is stopped (STOP state). Otherwise, there is a risk of
damaging the converter. For more information, refer to section 2.3 of the MFC710 user's manual.
mfc710acr-01.1-en
L1
L2
L3
PE
U
V
W
DI5
+24V
K11
K12
Power supply
for the
pre-charging
contactor
Confirmation of the
pre-charging contactor activation
Permission to switch on
the pre-charging contactor
PE
Power
supply
network
PE
Asynchronous
motor
K
Input filter
Pre-charging
resistors
(MFC1000/113)
Transistor
input
bridge
Transistor
output
bridge
Varistor overvoltage
protection
Pre-charging
contactor
coil
L1'
L2'
L3'
MFC710/AcR
Fuse
(gR or aR)
K - Pre-charging contactor
L1_1
(x10_2)
L1_2
(x10_1)
L2_2
(x11_2)
L2_1
(x11_1)
Fig.3.1. Electrical connection diagram of the MFC71/AcR converter - option I
mfc710acr-02.1-en
L1
L2
L3
PE
U
V
W
DI5
+24V
K11
K12
Power supply
for the
pre-charging
contactor
Confirmation of the
pre-charging contactor activation
Permission to switch on
the pre-charging contactor
PE
Power
supply
network
PE
Asynchronous
motor
K
Input filter
Transistor
input
bridge
Transistor
output
bridge
Varistor overvoltage
protection
Pre-charging
contactor
coil
L1'
L2'
L3'
MFC710/AcR
Fuse
(gR or aR)
K - Pre-charging contactor
L11
L21
L31
Pre-
charging
resistors
Fig. 3.2: Electrical connection diagram of the MFC71/AcR converter - option II
8
TWERD Power Electronics
