Rules for the Technical Engineering of Cable Radio and Television Systems Article 25

The system should possess enough electricity reserved as spare electric power for back up at the time of city electric power interruption.
中文原文 有線廣播電視系統工程技術管理辦法第25條
系統應具適當電力之備用電源,以供市電中斷時使用。

English translation for reference only; the Chinese text prevails. Not legal advice.