Delta EB3000 Series User Manual page 452

2. Common-mode noise in the power cable is transmitted through the stray capacitance and coupled
into the adjacent signal cable, as shown in Figure A-2. Several methods can be applied to reduce
the effect of this common-mode noise; for example, shield the power cable and/or the signal
cables, separate the power and signal cables, take the input and output side of the signal cable
and twist them together to balance out the stray capacitance, let power cables and signal cables
cross at 90°, etc.
3. Common-mode noise is coupled via the power cable to other power systems then the cable of
such a power system is coupled to the transmission system, as shown in Figure A-3.
4. The common-mode noise of an unshielded power cable is transmitted to the ground via the stray
capacitance. Since both shielded wire and unshielded wire are connected to a common ground,
other systems can be interfered with by the common-mode noise that is transmitted from the
ground back to the system via the shield. See Figure A-4.
Unshielded cable
Noise
Cstray
Power
Cable
supply
Ground
Unshielded cable
Noise
Send
Ground
A-5
Appendix A. EMC Standard Installation GuideEB3000
System
Cstray
Receive
Load
Figure A-2
Figure A-3