Rockwell Automation DC3N DC Drive User Guide, 1/4-2HP-115/230 VAC - Manual (Page 16)

8 Installation
As a general rule, Reliance Electric recommends shielding of all conductors if:
• wire lengths exceed 4 inches and power and control wiring must be bundled
together*;
• radiated and/or conducted noise must be minimized due to concerns about
immunity or general compliance (CE, FCC, etc.)
It may be necessary to earth ground the shielded cable. If noise is produced by
devices other than the drive, ground the shield at the drive end. If noise is
generated by a device on the drive, ground the shield at the end away from the
drive. Do not ground both ends of the shield.
If the drive continues to pick up noise after grounding the shield, it may be
necessary to add AC line filtering devices, or to mount the drive in a less noisy
environment.
Isolation
*Reliance Electric considers this an unfavorable condition and does not recommend bundling of power and
logic leads for any length.
ATTENTION: If it is not practical to shield power conductors, Reliance
Electric recommends shielding all logic-level leads. If shielding is not practical,
use twisted-pair control wiring to minimize induced electrical noise.
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Shielding guidelines
ATTENTION: Distribution system capacity above the maximum
recommended system KVA requires the use of an isolation transformer, a line
reactor, or other means of adding similar impedance to the drive power input.
Failure to observe these precautions could result in damage to, or destruction
of, the equipment.
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Input isolation transformers might be needed to help eliminate the following:
·
Damaging line voltage transients from reaching the drive.
· Line noise from the drive back to the incoming power source.
· Damaging currents that could develop if a point inside the drive becomes
grounded.