Emotron VS Series Quick Start Guide
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lines in parallel with power lines or bundle them up.
t orthogonally cross power lines if this cross inevitable.
-thick pipelines or
buried cement groove, also, power lines can be put into metallic conduit and grounded well with
shielded cables.
-core motor cables of which one is grounded at close side of the drive and the other side is
connected to motor enclosure.
noise filter. For example, ferrite common mode choke can restrain radiation noise of power lines.
3.7.2 Grounding
Recommended ground electrode is shown in the figure below:
Fig 3-28 Inverter grounding diagram
Use to the fullest extent the maximum standard size of grounding cables to reduce the impedance
of grounding system;
Grounding wires should be as short as possible;
Grounding point shall be as close to the drive as possible;
One wire of 4-core motor cables shall be grounded at the drive side and connected to grounding
terminal of motor at the other side. Better effect will be achieved if motor and drive are provided with
dedicated ground electrodes;
When grounding terminals of various parts of system are linked together, leakages current turns
into a noise source that may influence other equipment in the system, thus, grounding terminals of the
drive and other vulnerable equipment should be separated.
kept away from inlet & output of noise-sensitive equipment.
3.7.3 Leakage Current Suppression
Leakage current passes through the line-to-line and ground distributed capacitors at input &
output sides of drive, and its size is associated with the capacitance of distributed capacitor and the
carrier frequency. Leakage current is classified into ground leakage current and line-to-line leakage
current.
Ground leakage current not only circulates inside drive system, but may also influence other
equipment via ground loop. Such a leakage current may result in malfunction of RCD and other
equipment. The higher the carrier frequency of drive is, the bigger the ground leakage current would
be. The longer the motor cables and the bigger the parasitic capacitances are, the bigger the ground
leakage current would be. Therefore, the most immediate and effective method for suppression of
ground leakage current is to reduce carrier frequency and minimize the length of motor cables.
The higher harmonics of line-to-line leakage current that pass through between cables at output
side of drive will Accel the aging of cables and may bring about malfunction of other equipment. The
higher the carrier frequency of drive is, the bigger the line-to-line leakage current would be. The longer
the motor cables and the bigger the parasitic capacitances are, the bigger the line-to-line leakage
current would be. Therefore, the most immediate and effective method for suppression of ground
leakage current is to reduce carrier frequency and minimize the length of motor cable. Line-to-line
leakage current can also be effectively suppressed by mounting additional output reactors.
3.7.4 Use of Power Supply Filter
Since AC drives may generate strong interference and are also sensitive to outside interference,
power supply filters are recommended. Pay close attention to the following instructions during the use:
Enclosure of the filter needs to be reliably grounded;
Input lines of the filter shall be kept as far away from output lines as possible so as to avoid mutual
coupling;
Filter shall be as close to the drive side as possible;
Filter and drive must be connected to the same common ground.
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