1、字母区分:火线用L表示,是line的简写;零线用N表示,是null的简写;地线用E表示,是earth的简写。
![](https://video.ask-data.xyz/img.php?b=https://iknow-pic.cdn.bcebos.com/279759ee3d6d55fbb3596b3f61224f4a20a4dd0f?x-bce-process=image%2Fresize%2Cm_lfit%2Cw_600%2Ch_800%2Climit_1%2Fquality%2Cq_85%2Fformat%2Cf_auto)
2、电笔测试区分:在通电情况下用电笔测试,会亮的是火线;确定火线后,分别用剩下两条线与220V灯泡相连,再连接火线,通电,亮的是零线,暗的是地线。![](https://video.ask-data.xyz/img.php?b=https://iknow-pic.cdn.bcebos.com/9c16fdfaaf51f3dee927a47d98eef01f3a297915?x-bce-process=image%2Fresize%2Cm_lfit%2Cw_600%2Ch_800%2Climit_1%2Fquality%2Cq_85%2Fformat%2Cf_auto)
3、颜色区分:标准情况下,暖色调线(红、橙、黄等)是火线;冷色调线(黑、棕、蓝等)是零线;黄绿色相间(花线)的是地线。
![](https://video.ask-data.xyz/img.php?b=https://iknow-pic.cdn.bcebos.com/37d12f2eb9389b501f60fd4b8935e5dde7116e0f?x-bce-process=image%2Fresize%2Cm_lfit%2Cw_600%2Ch_800%2Climit_1%2Fquality%2Cq_85%2Fformat%2Cf_auto)
4、方向区分:在三孔插座上,标准情况下,左边是零线,右边是火线,上边是地线。对应的三孔插头零线和火线标注与之左右相反(镜像)。
![](https://video.ask-data.xyz/img.php?b=https://iknow-pic.cdn.bcebos.com/32fa828ba61ea8d383ac691d9b0a304e251f5818?x-bce-process=image%2Fresize%2Cm_lfit%2Cw_600%2Ch_800%2Climit_1%2Fquality%2Cq_85%2Fformat%2Cf_auto)