1、杆旁、控制箱旁、电缆拐弯处、电缆管直线长度超过50米时或两端电缆管不在同一平面相距100 mm以上时，必须设置手孔井。

Bar, next to the control box, cable bend, cable pipe line length more than 50 meters or both ends of the cable is not in the same plane are more than 100 mm apart, you must set up hand hole well.