3. Countermeasures against fire
1)The level and quantity of automatic equipment of fire warning alarm and fire protection shall be specified based on approval instruction documents.
2)Fire cocks in cable bridges and corridors shall be arranged within 100m from all points in cable bridges and corridors.
Article 225. Requirement for Cable Wells
The drainage pits and pumps for pumping out rainfall and underground water shall be installed at bottom of cable wells, which comply with the requirements in article 221.
Cables and connection boxes in cable wells shall be arranged on cable racks, troughs or separate plates.
The covers of cable wells shall have the handle to be held.
Article 226. Installation of Oil-Filled Power Cable Lines
Oil-filled cable lines shall be installed in compliance with requirement by the manufacturer.
Article 227. Ventilation Equipment and Lighting Systems
Both natural and forced ventilations are permitted for the ventilations in cable structures (except cable storey, cellar), but they shall be independent for each compartment. In the calculation of ventilations in cable structures, the difference of air temperature between inside and outside shall not exceed 10°C.
The flow of hot air in narrow and bending places is limited under this condition.
The ventilation equipment shall have the function (side board, chock valve) to block the air flow and to prevent the outside air flowing into cable structures in the event of the fire.
When cables are installed in cable rooms, the cables shall be takenattention to over-temperature of them due to the ambient air and impacts of technical equipment.
Chapter 3-2-6 Installation of Cable Lines in Production Halls, Water or Special Structures
Article 228. Installation of Cables in Production Halls
The distance between cables in production halls shall comply with the values shown in Table221-1 in this Guideline.
When power cable lines go nearby pipelines in parallel in production halls, the distance between the line and the pipeline shall not be less than the values shown in the following cable.
120
Table 228 Minimum distance between cable and pipeline in production hall
Type of pipeline |
Minimum distance (m) |
1.0
(0.5*)
Pipeline except above-mentioned pipeline 0.5
*Note: Above figure applies to the cables which is installed in narrow place and have protection against mechanical action with the length as long as approximate section and 0.5m longer than
the section at both sides.
When power cable lines cross the passage, the lines shall be arranged at higher than 1.8m.
Power cable lines under the floor and double floor shall be installed in troughs or pipes without compact arrangement.
In places where power cable lines go through walls or floors, pipes and holes for supporting the lines can be installed and opened slots shall be sealed with flame-resistant materials.
Article 229. Installation of Cables in Water
1.Arrangement at bottom
Power cable lines shall be arranged at thebottom of rivers, streams or canals where the cables do not inflected due to its weight and whose sharply acicular parts are smoothed.
Power cable lines shall be avoided to be arranged at reefs, abyss and place underwaterwith obstacles as much as possible. If it can not be avoided, the lines shall be installed in cable canals or troughs.
When oil-filled cables with voltage from 10kV to 220kV cross the rivers and streams as water transportation, the lines shall be installed in cable canals and be covered by sand on the top of the canals to protect against mechanical damage.
2.Depth at bottom
The depth of power cable lines at the bottoms of rivers, streams or canals shall comply with the values shown in the following table.
Table 229-1 Depth at bottom
Description of place |
|
Minimum depth (m) |
|
|
|
Banks and shallow places where ships or boats pass when oil-filled |
|
2.0 |
cables traverse at rivers, streams and canals. |
|
|
|
|
|
Banks and shallow places where ships or boats pass when cables |
1.0 |
|
except cables traverse at rivers, streams and canals. |
|
|
|
|
|
Dams and reservoirs whose bottoms are dredged periodically. |
Depth agreed by reservoir |
|
|
management agency |
|
|
|
|
3.Distance between underwater cables
The distance between cables of power cable lines underwater shall comply with the values shown in the following table.
121
Table 229-2 Distance between underwater cables
Description of distance |
|
|
Minimum distance |
|
|
|
|
|
|
Distance between cables installed at the |
bottoms of rivers, |
streams |
0.25m |
|
and canals. |
|
|
|
|
|
|
|
|
|
Distance between underwater cables. |
|
|
|
Specified by the design |
Distance between above-mentioned cable |
and |
cable of other lin |
5.0m |
|
installed in parallel. |
|
|
|
|
|
|
|
|
|
Distance between separated phases of |
cables |
installed |
underwater |
Specified by the design |
with the depth exceeding 15m or flow speed exceeding 1m/s. |
|
|
||
Horizontal distance between cables installed at the bottoms of rivers, |
Specified by the design |
|||
canals, reservoirs and lakes and pipelines (oil, gas, etc.) |
|
(50m* at least) |
||
*Note: Above distance are permitted to be reducedwith agreement between cables and pipelines of management units.
4.Requirement for brink
Power cable lines going into the water at places without complete embankment shall have surplus length of 10m at rivers or streams and 30m at the sea.
Cable cellars shall be constructed at the place where power cable lines go into the water.
Power cable lines at the embankments and shores shall be installed in cable pipes. The cable pipes shall be tilted and reinforced firmly in a cable cellar above the bank as well as at 1m or deeper from the bottom of the water level.
When power cable lines traverse the area where the boundary between water flow and bank, and the lines are affected byerosion, banks near them shall be consolidated to protect from erosion and flood (stake driving, dike construction, etc.).
Article 230. Installation of Cables under the Sea
For power cable lines are installed under the sea, cables shall be used armored cables covered by galvanized steel strands with the diameter not less than 6mm, or be installed in cable pipes.
Sediment at the bottom of the sea or the beach does not affect the cable due to tidal or wave.
Section of power cable lines at the shore shall be installed that human can not touch them easily and they can not be affected by the natural environment such as wind or rain.
Article 231. Prohibition of Crossing Other Cables in Water
If power cable lines are forced to cross with other power cable lines in the water, the solutions shall be agreed with by the manufacture and design agency mutually.
Article 232. Warning Plates on Banks
Warning signs for power cable lines on banks shall be installed in compliance with the requirements in this article in Technical RegulationVol.1.
122