the cross arm and the installation of insulator

the cross arm and the installation of insulator

Cross arm installation should be a right, the skew is not more than 20 mm, up and down or so skew is not more than 20 mm. Insulator installation should be solid, reliable connection, prevent water. Before installation. The insulator should be individually to determine insulation resistance.

(2) the whole stud

In pole should stop to stand up when a lift from the ground 0.5 meters, after the check by normal continue to stand up. Stand up to 60 degrees to 70 degrees should be tied to stand up when the reverse thread. Stand up to 80 degrees to 85 degrees, should stop to stand up when a fix will pull on both sides. After rod made, should immediately use theodolite is found from the front and sides simultaneously, install the chuck and backfill soil.

2. The tower group made

Tower group set method is divided into two categories: whole group decomposition of legislation and legislation. Whole set of legislation including purler herringbone derrick, a leg type herringbone derrick, etc. Decomposition group legislation including internal and external guy derrick decomposition tower, inversion group tower, etc.

(1) the tower ground preparation work before the assembly

According to the site topography and vertical tower method to determine ground assembly method. The ground before the assembly, field should be level off, lest component stress deformation.

(2) tower construction method

The current construction of transmission lines, the main use is decomposed group of tower construction method, there are foreign guy derrick decomposition group tower, stay within the derrick decomposition method. Guy derrick decomposition within the group characteristics of the tower is not affected by the influence of the terrain around the tower, reduces the anchor piles were set up for the required tools and workload. Can undertake double hanging at the same time, improve the efficiency of the construction.

(3) the bolt fastening

The Eiffel Tower adopts bolt connection, the degree of fastening bolt effect to the assembly

quality of the tower. After fastening degree is not enough, the tower stress components can produce sliding earlier, adverse to the structure.

(4) pay-off construction requirements

1. The coil set up

(1) pay-off, online plate hole through the shaft, and then put the shaft on both ends of the poles on the line frame bracket.

(2) adjust the pay-off stand, make its both ends as tall, and makes the coil from the ground.

(3) put the wire (steel wire), can be put on the wire set into the steel.

2. Alignment requirements

(1) put the aluminium wire or steel core aluminium wire, should be in advance of each pole on the cross arm hung three openings pulley, to lead to the root each pole, with a rope lift wires, embedded pulley. Continue to drag the wire, make its move along the pulley.

(2) the wire should be the one. Coil should have experience in personnel guards, responsible for check the quality of wire.

(3) when the pay-off should be reliable contact signal, along the way will be nursed conductor, so that they don't hurt, not dozen ring.

(5) wire connection requirements

1. Within each file from each wire shall have only one connector, but across important buildings, roads, rivers, railways, electric and telecommunication lines, such as wire and ground wire shall have a connector.

2. Different materials, different section or twist direction of wire connection, connection only dance line on the stem.

3. The mechanical strength of the joint is not less than 90% of the conductor is its own strength. Resistance is not more than 1.2 times with the length of wire resistance.

8 P093

4. The place such as tension bar, branch stem jumper wire connection, can be used T line and groove for clamp connection.

5. Pressure welding method of overhead lines, can be divided into the clamp pressure, hydraulic connection and detonation pressure connections.

(6) the completion acceptance inspection

1. The tower is upright, cross arm is perpendicular to line center.

2. The tower full high error values and tower foundation error value is in line with the original design requirements.

3. The guy is fastening, stress is the case.

4. Whether to conform to the requirements of the filled soil anchor pit, tower pit.

5. Check the sag, insulator string tilt, jump line electric distance whether meet the design requirements of the ministries.

6. The measured circuit conductor resistance in sunny day, shall not exceed the specified value.

7. The insulation resistance of measuring circuit conform to the standard requirements.

8. Under the rated voltage impact closing for no-load lines 3 times, have no problem to send.

Second, the cable and ground wire laying

(a) the requirements of cable laying

1. The buried cable installation requirements

(1) in cold area, cable should be buried in the permafrost.

(2) through a cable vibration and stress areas should wear protective tube.

(3) cable, parallel to the building outside the cable in the structure of the aproll slope should be.

(4) direct buried cable length should be between 1.5% and 2% longer than in cable trench, and make corrugated installation.

(5) cable, connector, terminal in turn and in and out of the building shall furnish obvious bearing marker such as location. Straight line should be appropriately adding peg.

(6) buried cable before backfill soil, shall be concealed engineering acceptance. Backfill soil should be layered compaction.

(7) the cover of the buried cable laying sand brick protection practice varies according to the different climate and environment.

2. The cable trench cable laying requirements

(1) power cable, in cable trench its horizontal interval is 35 mm, but should not be less than the cable diameter.

(2) the cable trench should be waterproof measures, should be not less than 0.5% at the bottom of the sewers, water drainage pipe or can be directly discharged into the sump pump discharge.

(3) power cables and control cables should be arranged separately.

(4) in cable trench shall assemble when entering the building fire wall.

(5) in cable trench appropriate USES reinforced concrete cover plate, the quality of each cover plate should not be more than 50 kilos.

3. The exhaust pipe of cable laying requirements

(1) local uniform load on the surface of over every square metre 100000 cattle, or by rail, reinforcement measures must be taken to protect the exhaust pipe from mechanical damage.

(2) the inner diameter of the pipe hole should not be less than 1.5 times of cable diameter, but the power cable tube hole diameter should not less than 90 mm, and control the pore diameter of the cable should be not less than 75 mm.

(3) the exhaust pipe shall have the tendency to manhole drainage slope is not less than 0.5% of the well side.

(4) row of pipe top should not be less than 0.7 meters off the ground.

(5) should strengthen cushion flat at the bottom of the trench, and should be laid not less than 80 mm thick concrete cushion layer.

(6), the branch should be set on the corner of line cable manhole Wells.

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(1) inside the shaft can not have has nothing to do with its pipelines through.

(2) shaft in high pressure, low pressure, emergency power supply of electrical wiring between each other should keep a distance of 0.3 M or above or not in the same shaft wiring.

(3) set a grounding bus bar shaft should be bright, respectively with embedded iron pieces, metal stents, good grounding cable metal sheath, etc.

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