AVG EZTouch I/O Jr., Manual

Page: 10 / 52

EZTouch I/O
Jr.
10 / 52
Shielding from RFI
Shielded Cables
Power cables, I/O cables or wiring, and communication cables should all be
separate so that they do not couple the conducted RFI on any of these wires/
cables. Another path for RFI into the PLC is through its RS232 port. Hence, the
cables to this port must be shielded properly.
Equipment Cabinets
As mentioned, equipment cabinets typically incorporate one or two doors and/
or hinged cabinet panels. In addition, sub-panels may be utilized on those
electronic controls and electromechanical items that are mounted. The goal is
to create a medium for mounting the equipment and ensure grounding of the
control's chassis to it. However, the door hinges and swinging panels by
themselves are not enough to ensure adequate grounding.
Similarly, the equipment enclosures are generally either painted or anodized.
Mounting of painted or anodized enclosures to like surfaces also does not
ensure good metallic contact between the equipment chassis and cabinet. It is
imperative that the equipment chassis are grounded such as through the use of
grounding straps as illustrated below.