Phase opposite protection: It is a safeguard acting immediately, which protects L1, L2,L3 three phase against wrong connection sequence. In this case, the yellow indicator light will be lighted.

• 错相保护：防止L1、L2、L3三相交流电源相序接错的一种保护措施。即时动作。指示灯形式为：黄灯亮；