Which practice supports EMI reduction when using shielded cables?

Which practice supports EMI reduction when using shielded cables?

• A. Route away from high-power or RF lines
• B. Run parallel to high-current lines
• C. Cross lines multiple times
• D. Place near heat sources

Answer: (A)

Keeping EMI away from the cable is the most effective way to preserve the shield’s performance. When shielded cables are routed away from strong EMI sources like high-power or RF lines, the electromagnetic fields interacting with the cable are much weaker, so less interference is induced in the shield and conductors. Distance reduces both coupled electric and magnetic noise, helping the signal stay clean. Running parallel to high-current lines exposes the cable to steady, strong magnetic fields along its length, which can drive noise into the shield and inner conductors. Crossing lines at right angles can help in some cases, but doing it repeatedly isn’t a reliable or simple mitigation and still isn’t as effective as increasing distance from the source. Placing the cable near heat sources doesn’t address EMI and can introduce thermal problems, so it’s not a valid EMI-reduction practice. So, the best practice is to route shielded cables away from high-power or RF lines.

Keeping EMI away from the cable is the most effective way to preserve the shield’s performance. When shielded cables are routed away from strong EMI sources like high-power or RF lines, the electromagnetic fields interacting with the cable are much weaker, so less interference is induced in the shield and conductors. Distance reduces both coupled electric and magnetic noise, helping the signal stay clean.

Running parallel to high-current lines exposes the cable to steady, strong magnetic fields along its length, which can drive noise into the shield and inner conductors. Crossing lines at right angles can help in some cases, but doing it repeatedly isn’t a reliable or simple mitigation and still isn’t as effective as increasing distance from the source.

Placing the cable near heat sources doesn’t address EMI and can introduce thermal problems, so it’s not a valid EMI-reduction practice.

So, the best practice is to route shielded cables away from high-power or RF lines.