User`s manual

6-2
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Wiring with noise countermeasures
For your safe usage of the JW300, observe the "Precaution for Wiring" of the previous page carefully.
Wiring to prevent the JW300 from malfunction caused by noise is shown below. Besides, some
malfunctions by noise come from complex causes or a cause, which cannot be analyzed in quantity.
Use the following noise countermeasures as your reference, when you take measures for each actual
situation.
(1) Grounding (how to connect the ground lines)
Grounding has two purposes; to protect operators from electric shock and to prevent malfunction
by noise. The grounding for noise prevention is shown here.
Don't use a common ground for the JW300 and other device.
When the GND cable of the JW300 is also used for grounding for other device, noise might come
into the JW30H from other device.
Bad example: Don't use the GND line of the JW300 for grounding of a motor or an inverter.
Countermeasure 1: Separate grounding for each of the JW300, the motor and the inverter.
Use a twisted wire of over 2 mm
2
sectional area and less than 5 m long in grounding the JW300 for
the noise prevention purpose.
Countermeasure 2: When separate grounding is not available.
If a separate grounding for the JW300 cannot be made, ground directly from
the GND terminal of the JW300 to the chassis on which the JW300 is mounted.
Common
grounding
Other
device
PLC
Control panel
Motor (heavy load)
Ground
PLC
ground
Inverter
ground
Terminal block
Class-D grounding
Motor (heavy load)
PLC
ground
Inverter
ground
Terminal block
Less than 5m
Motor (heavy load)
Ground
PLC
ground
Inverter
ground
Terminal block
Ground direct
to chassis