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4
WIRING
POWER CONNECTION
PROGRAMMING PORTS
RS232/PG
USB/PG
ETHERNET
EMC INSTALLATION GUIDELINES
Although Red Lion Controls Products are designed with a high degree of
immunity to Electromagnetic Interference (EMI), proper installation and wiring
methods must be followed to ensure compatibility in each application. The type
of the electrical noise, source or coupling method into a unit may be different for
various installations. Cable length, routing, and shield termination are very
important and can mean the difference between a successful or troublesome
installation. Listed are some EMI guidelines for a successful installation in an
industrial environment.
1. To reduce the chance of noise spikes entering the unit via the power lines,
connections should be made to a clean source. Connecting to circuits that also
power loads such as contactors, relays, motors, solenoids etc. should be avoided.
2. The unit should be mounted in a metal enclosure, which is properly connected
to protective earth.
3. Use shielded (screened) cables for all Signal and Control inputs. The shield
(screen) pigtail connection should be made as short as possible. The
connection point for the shield depends somewhat upon the application.
Listed below are the recommended methods of connecting the shield, in order
of their effectiveness.
a. Connect the shield to earth ground (protective earth) at one end where the
unit is mounted.
b. Connect the shield to earth ground at both ends of the cable, usually when
the noise source frequency is over 1 MHz.
c. Connect the shield to common of the master and leave the other end of the
shield unconnected and insulated from earth ground.
4. Never run Signal or Control cables in the same conduit or raceway with AC
power lines, conductors feeding motors, solenoids, SCR controls, and
heaters, etc. The cables should be run through metal conduit that is properly
grounded. This is especially useful in applications where cable runs are long
and portable two-way radios are used in close proximity or if the installation
is near a commercial radio transmitter. Also, Signal or Control cables within
an enclosure should be routed as far away as possible from contactors, control
relays, transformers, and other noisy components.
5. Long cable runs are more susceptible to EMI pickup than short cable runs.
Therefore, keep cable runs as short as possible.
6. In extremely high EMI environments, the use of external EMI suppression
devices is effective. The following EMI suppression devices (or equivalent)
are recommended:
Ferrite Suppression Cores for signal and control cables:
Fair-Rite part number 0443167251 (RLC part number FCOR0000)
TDK part number ZCAT3035-1330A
Steward part number 28B2029-0A0
Line Filters for input power cables:
Schaffner part number FN610-1/07 (RLC part number LFIL0000)
Schaffner part number FN670-1.8/07
Corcom part number 1 VR3
Visit RLC's web site at www.redlion.net for more information on EMI
guidelines, Safety and CE issues as they relate to Red Lion Controls products.