注：常规出厂的CM 2 Z四极断路器中性极电流值符合表二，用户也可自行100%保护设定。
Note: Normally, current values of neutral pole of CM2Z four-pole, conform to table two, and it can be setted by users with 100% protection.
注：对CM1-160 、225四极断路器，其中性极（N ）的 瞬时 脱扣器（ 短路保护）均 无5In规格。
Note:For CM1-160,225 four-poles breakers, the instantaneous release of N-pole (short-circuit protection) have no 5 In spec.
文章主要阐述了中性线的工况和各种不同接地系统中四极开关的应用及应用中需要注意的问题。
The paper mainly gives the work condition of neutral current, introduces application of four-pole switch in different grounding systems and problems to be noticed.
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