感謝上面幾位網友，以上述關鍵字查到建築物屋內外電信設備工程技術規範
有以下相關資料。
10.2.4 宅內配管設計
(1)電信配管與低壓電力線應相隔 15cm 以上，與高壓線應相隔 50cm 以上。但低壓
電力線或電信線纜具接地遮蔽效果者、或收容於接地金屬管內或宅內配線箱者及
出線匣處，不在此限。

這是電工規範。15公分以上，但是具接地或遮蔽效果不在此限

而根據EIA-569B
Electromagnetic Interference
Voice and data telecommunications cabling should not be run adjacent
and parallel to power cabling – even along short distances – unless one
or both cable types are shielded and grounded. For low voltage communication
cables, a minimum 5-inch distance is required from any fluorescent lighting
fixture or power line over 2 kVA and up to 24 inches from any power line over
5 kVA*. In general, telecommunications cabling is routed separately, or several
feet away from power cabling. Similarly, telecommunications cabling is routed
away from large motors, generators, induction heaters, arc welders, x-ray
equipment and radio frequency, microwave or radar sources.
任何通訊線都不建議臨近且平行於電力線，即使只是一小段。除非採用遮蔽且有接地。
低壓通訊線至少須距離日光燈或大於2kVA的電力設備5吋，也就是12.5公分左右，跟電工法規差不多。
距離任何高於5kVA的設備都需要距離24吋也就是60公分左右
大致上跟各位所言相符。