V1.03
15.4.29
3EMC Installation Guidelines
Although all Monico Gateways™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 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.
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.
The unit should be mounted in a metal enclosure, which is properly connected to protective earth.
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.
oConnect the shield to earth ground (protective earth) at one end where the unit is mounted.
oConnect the shield to earth ground at both ends of the cable, usually when the noise source
frequency is over 1 MHz.
oConnect the shield to common of the Data Station and leave the other end of the shield
unconnected and insulated from earth ground.
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.
Long cable runs are more susceptible to EMI pickup than short cable runs. Therefore, keep
cable runs as short as possible.
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:
oFair-Rite part number 0443167251 (RLC part number FCOR0000) TDK part number ZCAT3035-
1330A
oSteward part number 28B2029-0A0
oLine Filters for input power cables:
oSchaffner part number FN610-1/07 (RLC part number LFIL0000) Schaffner part number FN670-
1.8/07
oCorcom part number 1 VR3
