1. How many types of cable laying methods are currently used?

(1) Manual laying, that is, using a sea of people strategy, under the coordination and command of one or more people, laying according to regulations;  (2) Mechanized laying, which uses rollers, pullers, and conveyors and is controlled by a synchronous power supply, is relatively safe;  (3) Combining labor and machinery, this method is adopted in some sites due to the large number of turns, the difficulty of construction, and the difficulty of using all machinery.

2. What requirements should the control secondary circuit wiring meet?

① The construction and wiring are correct according to the drawing;  ② The electrical connection of the conductor should be firm and reliable;  ③ The wires in the panel and cabinet shall not have joints, and the core wires of the wires shall be free of damage;  ④ The end of the cable core should be marked with its circuit number, which should be correct, with clear handwriting and not easily discolored;  ⑤ The wiring should be neat, clear, and beautiful, and the insulation of the wire should be good and undamaged;  ⑥ The wiring on each side of each wiring terminal should be one, and the maximum number should not exceed two.

3. What are the requirements for cable banks?

① The distance from the top of the exhaust pipe to the ground is 0.2m in the factory building, 0.5m under the sidewalk, and 0.7m in general areas;  ② Install a drainage well at the change of direction and branches, and add a well when the length exceeds 30mm;  ③ The pit depth shall not be less than 0.8m, and the manhole diameter shall not be less than 0.7mm;  ④ The drainage pipe shall have a drainage slope of 0.5% to 1% inclined to the well pit.

4. What are the requirements for the resistance of cable conductor connection points?

The resistance of the connection point is required to be small and stable, and the ratio of the resistance of the connection point to the conductor of the same length and cross-section should not be greater than 1 for newly installed terminal heads and intermediate heads; The ratio of terminal head to intermediate head in operation should not be greater than 1.2.

5. What requirements should be met for the design of cable joints and intermediate joints?

The requirements to be met include:① High compressive strength, good conductor connection;  ② High mechanical strength, low medium loss;  ③ Simple structure and strong sealing performance.