The advantages of using shielded cable for 50-pair telephone lines primarily lie in electromagnetic interference (EMI) protection, signal stability, and safety.
EMI Protection
The shielding layer, made of metal braid or aluminum foil, effectively suppresses external electromagnetic interference (EMI) from affecting the signal while also blocking internal signal radiation, preventing interference with other devices.
Signal Transmission Stability
In industrial environments (such as near inverters and motors) or in high-interference scenarios, the shielding layer reduces signal attenuation, ensures signal integrity, and reduces data error rates.
Safety
The shielding layer reduces the risk of electric shock from cable damage and provides a certain degree of protection against electrostatic discharge.
Installation Specifications
In high-interference environments (such as when parallel to AC 380V power lines with a distance less than 50cm), use armored shielded cable (such as HYA53) and further enhance shielding effectiveness through single-ended grounding (ground resistance ≤ 5Ω).