10
2.
Introduction of Shihlin Inverter
Introduction of Inverter
Commonly signal wire (weak) and power wire (heavy) are in control cabinet, for the inverter,
power wire is divided into
input line and output line.
Signal wire is easily interfered by power wire, so that
causing the misoperation of the device.
When wiring, signal wire and power wire should be distributed in
different areas, parallel lines and interlaced lines are forbidden at close range(within 20cm), and
especially don’t bundle up the two lines.
If the signal cables must pass through the power lines, the
two should keep 90 degree Angle.
Interlace lines and banding together is also forbidden for the input
and output line of power wire, especially on the occasions which noise filter is installed. It will cause
the coupling of electromagnetic noise through the distributed capacitance of the input and output
lines, thus the noise filter will out of action.
Generally a control cabinet has different electric equipments such as inverter, filter, PLC,
measurement instrument, their ability of emitting and bearing electromagnetic noise are diverse from
each other, and this requires classifing these equipments. The classification can be divided into
strong noise equipment and noise sensitive equipment, Install the similar equipments in the same area
and, and keep a distance more than 20cm among inhomogeneous equipments.
2.
Input noise filter, input and output magnet ring (zero phase reactor)
Adding noise filter to the input
terminal, the inverter will be isolated from the other equipments,
and its ability of conduction and radiation will be reduced effectively.
The better EMI suppression effect
will be obtained by
installing the input reactor recommended by this manual. By adding winding ferrite
bead to the input and output terminal and coordinating with internal filter, the inverters will meet the
CE declared and have a better effect.
3. Shielding
Good shielding and grounding can greatly reduce the interference of inverter, and can improve
the anti-interference ability of the inverter. Sealing off the inverter with the good conductive sheet
metal and connecting the sheet metal to ground, the limit value of radiation which CE declared will
be met.
4. Grounding
The inverter must be connected to the ground safely and reliably. Grounding is not only for
equipment and personal safety, but also the simplest, the most efficient and the lowest cost method to
solving the EMC problem, so it should be prioritized. Please refer to the section of "terminal wiring".
5. Carrier
The leakage current contains the leakage current from line to line or
over the ground. It depends
on the size of the distributed capacitance when wiring and the carrier frequency of the frequency. The
higher the carrier frequency, the longer the motor cable, and the larger the cable cross-sectional area
is, the larger the leakage current is.
Reducing the carrier frequency can effectively reduce the leakage
current. When the motor line is long (50m above), the output side should be installed with ac reactor
or sine wave filter, when the motor line is longer, a reactor should be installed every other distance.
At the same time, reducing carrier frequency can effectively reduce the conduction and radiation
interference, and the limits value of the conduction and radiation which CE declared can be met in
2K carrier frequency.
