Rockwell Automation 1305 AC Drive, Series A and B, Firmware 4.xx-5.xx - Manual (Page 23)

Chapter 2 – Installation/Wiring
2-7
ELECTRICAL INTERFERENCE – EMI/RFI
Immunity
The 1305 drive is designed for immunity to most externally
generated interference. Usually, no special precautions are
required beyond the installation practices provided in this
publication.
It is recommended that the coils of DC energized contactors
associated with drives be suppressed with a diode or similar
device, since they can generate severe electrical transients.
In areas subject to frequent lightening strikes, additional surge
suppression is advisable.
Emission
Careful attention must be given to the arrangement of power
and ground connections to the drive to avoid interference with
nearby sensitive equipment. The cable to the motor carries
switched voltages and should be routed well away from
sensitive equipment.
The ground conductor of the motor cable should be connected
to the drive ground (GRD) terminal directly. Connecting this
ground conductor to a cabinet ground point or ground bus bar
may cause high frequency current to circulate in the ground
system of the enclosure. The motor end of this ground
conductor must be solidly connected to the motor case ground.
Shielded or armored cable may be used to guard against
radiated emissions from the motor cable. The shield or armor
should be connected to the drive ground terminal and the
motor ground as outlined in the Grounding section of this
Installation chapter.
Common mode chokes are recommended at the drive output to
reduce the common mode noise.
An RFI filter can be used and in most situations provides an
effective reduction of RFI emissions that may be conducted
into the main supply lines.
If the installation combines a drive with sensitive devices or
circuits, it is recommended that the lowest possible drive PWM
frequency be programmed.