Cables - Delta AH Motion Series Hardware Manual

AH Mo t io n – H ar d war e M a nu a l
- The diameter of a hole in the control box must be less than 10 millimeters, i.e. 3.94 inches. If the diameter of the
hole is larger than 10 millimeters, the radio frequency noise may be emitted.
- To prevent the radio waves from leaking through the interval between the door of the control box and the PLC, the
interval needs to be reduced. Besides, users can prevent the radio waves from leaking by putting an EMI gasket
on the painted surface.
 Connecting a power cable and a ground
The power cable of the PLC system and the ground are connected in a way described below.
- Provide a ground point near the power supply module. Use thick and short wires to connect the terminals LG and
FG with the ground. (The length of the wire should be less than 30 centimeters, i.e. 11.18 inches.) LG and FG
function to pass the noise generated by the PLC system to the ground. Therefore, the impedance should be as low
as possible. Besides, the wires are used to relieve the noise. They themselves carry a lot of noise. Using the short
wires can prevent the wires from acting as antennas.
- Twist the ground and the power cable. After the ground and the power cable are twisted, the noise flowing through
the power cable is passed to the ground. If a filter is installed on the power cable, the ground and the power cable
do not need to be twisted.
A.1.3 Cables
Grounding a shielded cable
Cables drawn from the control box carry high-frequency noise. When they are outside the control box, they are like
antennas emitting noise. To prevent the emission of noise, the cables connected to digital input/output modules, analog
input/output modules, temperature measurement modules, network modules, and motion control modules should be
shielded cables.
The use of shielded cables also increases the resistance to noise. If the signal cables connected to digital input/output
modules, analog input/output modules, temperature measurement modules, network modules, and motion control
modules are shielded cables, and are grounded properly, the resistance to noise is improved. However, the resistance to
noise will not meet the specified requirement if users do not use shielded cables or the shielded cables are not grounded
_A
correctly. If the shield of a cable is connected with the control box, users have to make sure that the shield contacts the
control box. If the control box is painted, users have to scrape the paint. All fastening must be metal, and the shield must
contact the surface of the control box. If the surface is not even, users need to use washers to correct the unevenness, or
use an abrasive to level the surface.
If the shield of a shielded cable is grounded, it needs to be as close to a module as possible. Users have to make sure that
there is no electromagnetic induction between the cable which is grounded and other cable which is grounded. Besides,
users have to take appropriate measures so that the shield of a cable contacts the control box.
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