Noise Countermeasures - Epson RC620+ Manual

Setup & Operation 3. Installation

3.5 Noise Countermeasures

To minimize electrical noise conditions, the following items must be observed in the
system's cable wiring:
To minimize electrical noise condition, be sure of followings for wiring.
- The earth wire of the power supply should be grounded. (Ground resistance: 100 Ω or
less) It is important to ground the frame of Drive Unit not only for prevention from
electric shock, but also for reducing the influence of electric noise around the Drive
Unit. Therefore, be sure to connect the earth wire (yellow/green) of the Drive Unit's
power cable to the ground terminal of the factory power supply. For details about the
plug and AC power cable, refer to the Setup & Operation 3.3 Power Supply.
- Do not tap power from a power line that connects to any equipment which may cause
noise.
- When you tap power for the Drive Unit and the single-phase AC motor from the same
power line, change the phase of one or the other. Ensure that they will not be the
same phase.
- Use a twisted pair motor power line.
- Do not run AC power lines and DC power
lines in the same wiring duct, and separate
them by at least 200 mm.
separate the AC motor power line and the
Drive Unit power line by at least 200 mm from
the sensor or valve I/O lines; and do not bundle
both sets of wiring with the same cable tie. If
more than one duct/cable must cross each
other, they should cross perpendicularly. The
preferable example is shown in the right figure.
- Wire as short as possible to the I/O connector and EMERGENCY connector. Use a
shielded cable and clamp the shield to the attached connector interior. Make sure to
keep away from the peripheral noise source as far as possible.
- Make sure that the induction elements used to connect to the Drive Unit's I/O (such as
relays and solenoid valves) have surge suppressors. If an induction element without a
surge suppressor is used, make sure to connect a rectifying diode located at the
induction element in parallel with it. In selecting a rectifying diode, make sure that it
can handle the voltage and current incurred by the induction load.
- To start and change revolutions of the conveyer's (or the like's) AC motor (ex: an
induction motor or three-phase induction motor) regularly or abruptly, make sure to
install a spark suppressor between the wires. The spark suppressor is more effective
when placed closer to the motor.
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For example,
AC Line duct
200 mm or more
DC line duct
RC620DU Rev.5