G&L MMC-A2, Hardware Manual

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Installation, Operation, & Maintenance
G & L Motion Control Inc. MMC Hardware Manual 21
Figure 3-6: Connecting Shielded Cable
The two different methods of terminating shields are used to
accommodate two different immunity requirements. Immunity
required inside an enclosure is considered lower because cables are
typically less than three meters in length and/or can be separated
from each other and from noise sources.
Immunity required external to an enclosure is considered higher
because the user may have less control over the noise environment.
Low level signal cables that can be external to an enclosure are
tested at a 2 KV level for electrical fast transients (EFTs). Low level
signals that can be less than three meters in length or can be
separated from noise sources are tested at a 1 KV level. Under the
stated conditions, there will be no disturbance of digital I/O,
encoder, or encoder operation. For analog signals, there may be
momentary disturbances but there will be self-recovery when the
noise subsides.
Do not operate transmitters, arc welding equipment, or other high
noise radiators within one meter of an enclosure that has the door
open. Continue to equip inductive devices, if they are in series with
a mechanical contact or switch, with arc suppression circuits. These
devices include contactors, solenoids and motors. Shield all cables
that carry heavy current near the system, using continuous foil wrap
or conduit grounded at both ends. Such cables include power leads
External
Drive
MMC
Cabinet
Enclosure