Drive Setup CDHD
74 User Manual
Motor and feedback cables m ust be shielded in order to m inimize noise
em issions and increase the im munity levels of the drive system . The shield
should be connect ed t o ground at both ends.
The proper bonding of shielded cables to a grounded surface is imperative for
minim izing noise emissions and increasing immunity levels of the drive system .
I ts effect is to reduce the im pedance bet ween the cable shield and the back
panel. It is recom mended that all shielded cables be bonded t o the back panel.
The m otor and feedback cables should have the shield exposed as close to the
drive as possible. This exposed shield is bonded to the back panel using either
non-insulated metallic cable clam ps or cable bonding clamps.
It is recom mended to use a star point shield connection, for exam ple with a
shielding busbar.
For cables entering a cabinet, connect shields on all 360° of the cable.
Lines bet ween servo drives and filters and external brake resistor must be
shielded.
5 .3 .4 I nput Pow er Filt ering
The CDHD electronic system com ponents require EMI filtering in the input power
leads to meet the CE/EMC requirements for the industrial environment. This
filtering blocks conduct ed type em issions from exiting ont o the power lines and
provides a barrier for EMI on the power lines.
Care must be taken to adequately size the system. The type of filter is
determined according to the voltage and current rating of the system and
whether the incoming line is single- or three-phase. One input line filter can be
used for m ult i-axis control applications.
Implementation of the input power filter must adhere to the following guidelines:
Maintain separation of leads ent ering and exiting the m ains filter.
Filt er must be m ounted on the sam e panel as t he drive.
Filter must be mounted as close as possible to the drive, to prevent noise
from being capacitively coupled int o other signal leads and cables.
When m ount ing t he filter to the panel, remove any paint or material
covering. Use an unpainted metallic back panel, if possible.
Filters are provided with a ground connection. All ground connections must
be tied to ground.
Filters can produce high leakage currents. Filt ers must be grounded before
connecting the supply!
Filters should not be touched for 10 seconds after removing the supply.
5 .3 .5 Mot or Line Filt er ing
Motor line filt ering using ferrite cores m ight be necessary for CE compliance of
CDHD systems. This additional filtering can increase the reliability of the system.
Poor non-metallic enclosure surfaces and lengthy, unbonded (or unshielded)
motor cables that couple noise line-to-line (differential) are just som e of t he
factors that result in a need for m otor lead filtering.
Motor lead noise m ay be either comm on-m ode or different ial. The com m on-
mode conducted currents occur between each motor lead and ground (line-to-
ground). Differential radiated currents exist from one m ot or lead t o another
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