Chapter 9 Options
82
Ch
ap
ter 9
Plurality of double-shielded twisted pair cable
plurality of single-shielded twisted pair cable
Diagram
1
Diagram
2
For low-voltage digital signals, double-shielded cable is the best choice, but can also be a
single-shielded or unshielded twisted pair, as shown in Figure 2, however, the frequency of the
signal, it can only use a shielded cable.
Relay cable need to use cables with metal braid shield.
Need to use a network cable to connect the keyboard, for electromagnetic environment is more
complex place, it is recommended to use shielded cable.
Note: analog and digital signals using different cables routed separately.
3..Interference Counte
Connect noise filter on the output side of inverter can reduce inductive interference and radio
interference .
→Inductive interference
：
The electromagnetic induction makes the signal line noise when
upload signal ,and then cause the control equipment malfunction.
→ Wireless interference
：
The high-frequency electromagnet wave emitted by the inverter and
cables will interfere with the nearby wireless device and make it noise when receiving signal.
→ Installation of noise filter as below :
M
MCCB
Inverter
PI500
Noise
Filter
Radio Set
Conduction
interference
Control
equipment
The signal line
AC input
(1)
Inductive interference countermeasure : in addition to the installation of noise filter , it can
also import the output cables to grounded metal tube. The distance between the output cable and
signal line is greater than 30cm , the influence of inductive interference is also significantly
reduced . As shown below :
MCCB
Inverter
PI500
Metal tube
30cm Above
The signal line
Control
equipment
M
AC input
(2)
Radio frequency (RF) interference countermeasure : the input cables, output cables and
inverter itself can produce interference , to install noise filter on both sides of input and output and
shield the inverter with metal box can reduce the radio frequency interference . As shown below :
AC input
MCCB
PI500
Inverter
Noise
Filter
Noise
Filter
Iron box
Iron box
Metal tube
M
