
3.Wiring
3-15
3.6.2 Wiring on the output side of main circuit
3.6.2.1 Precautions when wiring on the output side of main circuit
• Never connect a power supply to output terminals U/T1, V/T2,
and W/T3.
Otherwise, it may damage the internal circuits of the inverter.
• Never short or ground output terminals.
• The output wires should not have contact with the inverter heatsink.
• Do not connect a phase advancing capacitor or LC/RC noise
filter to an output circuit.
Otherwise, it may damage the inverter or cause a fire.
•
Do not connect an electromagnetic switch or MC to an output
circuit.
Otherwise, it will actuate the overcurrent protection circuit of the
inverter.
3.6.2.2 Connecting the inverter and motor
• Connect output terminals U/T1, V/T2, and W/T3 to motor wires U, V,
and W respectively.
• Check if the motor rotates in correct direction according to the
command. If not (motor rotating in reverse with the forward run
command), switch any of two output terminals to each other and
reconnected them.
3.6.2.3 Installing a noise filter on the output side
Install a noise filter to reduce radio noise and inductive noise.
Figure 3.7 Noise filter on the output side
IM
◠
◠
◠
Noise
filter
~
MCCB
E7
Power
Controller
AM radio
Radio noise
Inductive
noise
Signal
line
DANGER
!
Inductive noise: Noise generated on the signal line by electromagnetic
induction. It causes the controller to malfunction.
Radio noise: High-frequency noise generated from the inverter and cables.
3-16
MOSCON-E7 User’s Manual
3.6.3 Dealing with inductive noises
• As mentioned previously, noise filter can be used to prevent the
inductive noise generated on the output side.
• As an option, cables can be routed through a grounded metal pipe to
prevent inductive noise.
• If the metal pipe and the signal line are at least 30cm apart, the
inductive noise can be considerably reduced
.
Figure 3.8 Dealing with inductive noise
3.6.4 Dealing with radio interference (RFI)
• Radio noise is generated from the inverter as well as the input/output
lines.
• The radio noise can be reduced by installing the noise filters on both
input and output sides, and also installing the inverter in an enclosed
and grounded steel box.
• Make the cable between the inverter and motor as short as possible.
Figure 3.9 Dealing with radio interference
IM
◠
◠
◠
~
MCCB
Power
Noise
filter
Noise
filter
E7
Metal pipe
◠
◠
◠
~
MCCB
Power
IM
Controller
30cm Min.
Signal line
Metal pipe
E7