When the cable is dragged into the center of some all tube, a preliminary to the transformer tank slowly put transformer insulation sheath, then not so much the traction rope.
当电缆有些全部拽进中心管里时，初步往变压器油箱里慢慢地放变压器绝缘护套，这时不要过分地拉紧牵引绳。
2
The total area of the wires inside the tube (including the insulation coat) should not be more than 40% of the area of the internal section of the pipe.
管内导线包括绝缘层在内的总面积不应大于管子的内截面的40%。
3
When electric insulation is required, non-metallic coating, protective non-metallic tube or insulating joint, etc., can be adopted for the insulation implementation.