PART 3 TRANSMISSION AND DISTRIBUTION LINES

Chapter 3-1 House and Outside Wiring Systems with Voltage up to 35kV

Chapter 3-1-1 The Selection of Types of House and Outside Wirings with voltage up to 1kV and Installation Methods

Article 172. Appropriation for Power Projects

1.Environment condition

House and outside wirings shall not affect surrounding people and natural environment by noise or other influence.

2.Purpose and value of project

House and outside wirings shall supply electricity according to the demand of consumer

3.Construction and architectural feature.

House and outside wirings shall havesufficient mechanical and electrical strength which can withstand the assumed load and stress.

Article 173. Selecting Lines and Conductors, Cable Installation Methods

1.Installation method and selection of conductor and cable

Installation methods for house and outside wirings and selection of conductors and cables shall be complied with the requirements in the following table.

Insulations and protective covers of conductors and cables shall meet the installation method and environment conditions. Also, the insulations shall meet the nominal voltage of house and outside wirings.

Table 173 Installation method and selection of conductor and cable

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2.Particular requirements

(1)When there are special requirements specified by the characteristics of equipment, the insulation and protective covers of conductors or cables shall be selected inconsideration of such requirements.

(2)In places where ambient temperature is high, conductors and cableswith insulation sheath made

of high temperature resistancematerials shall be used. Conductors and cableswith insulation sheath made of normal heat-protective materials are prohibited to be used.

(3)In the case of installation in very humid hall or outdoor, the insulation of conductors, support and suspension structures, pipes, boxes and troughs shall be humidity resistant.

(4)In dusty halls, the installation methods which it is difficult to clean dusts accumulated on parts of

house and outside wirings shall not be applied.

(5) In the case of installation in allhalls or outdoor with highly active chemicals, all parts of house and outside wirings shallwithstand the impactsof such chemicals orbe protected from the impacts.

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(6)Conductors and cables with insulation or covers which are unstable to the sun light shall be protected from direct sun light.

(7)In places where house and outside wirings mightbe suffered from mechanical damage, opened conductors and cables shall be protected by protective covers. If the conductors and cables have such protective covers or the strength enough to withstand themechanical impacts, they shall be

inserted in pipes, boxes or barriers, or installed closely.

(8) In case of supplying electricity to power mobile or portable devices, flexible copper conductors or cables shall be used in consideration ofmechanical actions. Flexible copper conductors or cables, including earthing conductors, shall be placed in theshared enclosures, protective nets

and insulations. Machines (cranes, portable sawing machines, electric gate, etc.) which the movable scope is limited shall have measures to protect the conductors and cables for supplying electricity to them and being broken, such as. hanger rings of flexible conductors and rolling rack

of flexible cables.

(9)As for the places where oil or chemicals are put in, oil resistaconductors shall be used or conductors shall be protected from effects of such substances.

(10)The distance between different phases of conductors of house and outside wirings with voltage exceeding 1kV, the distance from conductors without sheath (IP00) to poles, and the distance from the conductors to the wall of the buildings or earthing systems shall not be less than 50mm. And, the distance from the conductors to flammable componentsof the building shall not be less than 200mm.

(11)The insulators of house and outside wirings shall be made of non-flammable materials.

The following additional requirements apply to the electricity system in the span of the crane:

(12) House and outside wirings shall comply with the following requirements, which cranes are in the span.

- House and outside wirings with noni-sulated conductors or conductors without protective covers, and installed on rafters shall not be less than the height 2of.5m above floors of the bridge or vehicle of cranes. Inthe cases that the height of the wirings is less than 2.5m but not less than the beams ofroof, the wirings shall be shielded for the wholelength to prevent inadvertent contact from the floor or vehicle. The above-mentioned shields are permitted to be suspended on the bridge or installed under the wirings.

- The section of the wirings without protective covers on the repairing compartments ofanecr shall be protected so that the live parts of the wirings would not to be touched by persons. If the wirings are at the height more than 2.5m from the floor of crane or insulatedconductors are

used at the section, it is not necessary to protect the wirings. In case of using insulated conductors, the height of the wirings shall be determined by the repairing conditions.

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- The wirings without protections against mechanical damage are permitted to be installed under crane in dead zone of crane. Busbars with protective covers and current up to 630A are not required to be applied protections against chemical impacts, which are placed near to technical equipment out dead zone of crane.

(13) House and outside wirings nearbuildings or halls of the project and outdoor explosive equipment shall comply with requirements stipulated in current standards on fire and explosion protection.

Article 174. Fire Safety Protection Conditions

1.Installation methods and selection of conductors and cables with respect to fire safety protection conditions

Installation methods and selection of conductors and cables with respect to fire safety protection conditions shall comply with the requirements in the following table.

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*Note: Non-flammable protective covers shall cover all sides ofconductors, cables, pipes and boxes not less than 10mm.

*2Note: Mortar, gypsum etc. with thickness not less than 10mm shall be plastered.

*3Note: Non-flammable solid layers such as cement mortar, gypsum or concrete shall thave thickness not less than 10mm.

2.Other requirements for installation method

(1)In the case that conductors or cables withflammable covers or conductors without protective covers are openly installed, the distance from the conductors or the cables tothe floor surface, structures and parts made of flammable materials shall be more than 10mm. If the distance is not ensured, conductors andcables shall be isolated from floor surface by non-lammablef layers

covering each side of the conductors or the cables with surplus not less than 10mm.

(2) In the cases that cables withflammable covers or conductors without protective covers are closely installed inclosed compartments or spaces of construction structures (e.g. the space between wall and plastered layer) or in slots etc. which are made of flammable materials,the conductors and cables shall be protected by non-flammable solid materials at all sides of them.

(3)When flame-resistant pipes and boxes for conductors or cables earopenly installed along the non-flammable and flame-resistant floors and structures, the distance from pipes and boxes to the surface of floors and structures orflammable parts shall be more than 100mm. If the distance is not ensured, non-flammable materials (mortar, gypsum, cement mortar, concrete, etc.) with the thickness of 10mmand more shall be placed betweenall sides of pipesor boxes as well as between the above-mentioned surfaces.

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