
Chapter 3: Wiring
Firmware – S1043
Revision: 2 (9/98)
36
© Saftronics, Inc.
Countermeasures Against Radio Interference
Radio noise is generated from the Inverter as well as from the input and output lines. To reduce noise, install noise
filters on both input and output sides, and also install the Inverter in a totally enclosed steel box.
The cable between the Inverter and the motor should be as short as possible.
Figure 3.12
Countermeasures Against Radio Interference
Cable Length Between Inverter and Motor
Steel box
Metal Conduit
If the cable between the Inverter and the motor is long, the high-frequency leakage current will increase, causing the
Inverter output current to increase as well. This may affect peripheral devices. To prevent this, adjust the carrier
frequency (set in C6-01 to C6-03) as shown in
Table 3.6
. (For details, refer to the user constant settings.)
Table 3.6
Cable Length between Inverter and Motor
Cable Length
50 m max
100 m max.
More than 100 m
Carrier Frequency
15 kHz max.
10 kHz max
5 kHz max.
(Set value: C6-01)
(15.0)
(10.0)
(5.0)
(Set value: C6-02)
(15.0)
(10.0)
(5.0)
(Set value: C6-03)
(0)
(0)
(0)
§
Ground Wiring
•
Always use the ground terminal of the 200 V Inverter with a ground resistance of less than 100
Ω
and that of the
400 V Inverter with a ground resistance of less than 10
Ω
.
•
Do not share the ground wire with other devices, such as welding machines or power tools.
•
Always use a ground wire that complies with technical standards on electrical equipment and minimize the
length of the ground wire.
Leakage current flows through the Inverter. Therefore, if the distance between the ground electrode and the
ground terminal is too long, potential on the ground terminal of the Inverter will become unstable.
•
When using more than one Inverter, be careful not to loop the ground wire.
Figure 3.13
Ground Wiring
VG5