Earthing - Emerson EV1000-2S0004G User Manual

possible, especially when they are routed in parallel for
rather long distance. If the signal cable must cross the power
cable or motor cable, keep them at right angle to each other.
>30cm
>20cm
Figure 3-23 Cable routing schematic diagram
If the section area of the motor cable is too big, the motor
should derate. Refer the drive's cable specs in Table 3-2.
Since the larger the section area of cables, the greater their
capacitance to the ground, therefore, the output current
should derate 5% with increasing every category of cable
section area.
Shielded/armored cable: high-frequency low-impedance
shielded cable should be used, such as woven copper mesh,
aluminum mesh or metal mesh.
The control cable should be shielded, and the clamps at both
ends of the metal mesh should be connected to the earth
terminal of the drive enclosure.
Use conductive plate and dentate pad to clear away the
paint between the screws and metal casing, to ensure good
conductivity.
PE
enclosure
Figure 3-24 Correct shied layer earthling
PE
Enclosure
Figure 3-25 Incorrect shield layer earthing

3.2.5 Earthing

Independent earthing pole (recommended)
Motor cable
>50cm
Power cable
Signal/Control cable
Power source or motor cable
Signal/Control cable
PE
enclosure
PE
Enclosure
EV1000 Series General Purpose Variable Speed Drive User Manual
Chapter 3 Installation and Wiring
drive
PE
Figure 3-26 Earthing Diagram 1
Shared earthing pole (acceptable)
drive
PE
Figure 3-27 Earthing Diagram 2
Shared earthing lines (not allowed)
drive
PE（G）
drive
PE
Figure 3-28 Earthing diagram 3
Besides, pay attention to the following points:
In order to reduce the earthing resistance, flat cable should
be used because the high frequency impedance of flat cable
is smaller than that of round cable with the same CSA.
For 4-core motor cable, the end of one cable should be
connected to the PE of the drive, and the other end should
be connected to the motor's enclosure. If the motor and the
drive each has its own earthing pole, then the earthing effect
is better.
If the earthing poles of different equipment in one system are
connected together, then the leakage current will be a noise
source that may disturb the whole system. Therefore, the
drive's earthing pole should be separated with the earthing
pole of other equipment such as audio equipment, sensors
and PC, etc.
In order to reduce the high frequency impedance, the bolts
used for fixing the equipment can be used as the high
frequency terminal. The paints on the bolt should be
cleaned.
The earthing cable should be as short as possible, that is,
the earthing point should be as close as possible to the
drive.
Earthing cables should be located as far away as possible
from the I/O cables of the equipment that is sensitive to
noise, and lead should also be as short as possible.
19
other
equipmen
other
equipment
Other
equipment
other
equipment