Article 197. Use of hermetic washers

As stipulated in Technical Regulation.

Article 198. Lighting equipment on cranes

As stipulated in Technical Regulation.

Article 199. Light for prevent of explosion

As stipulated in Technical Regulation.

Section 3 EQUIPMENT OF LIGHTING SYSTEMS

Article 200. MCCB and fuses

(1)Protection of the electric trunk line is based on the following

1.Overload and short circuit protection shall be performed.

2.The breaker shall be used as protection instrument according to the general rule of power distribution.

In addition, for electrical substation equipment, the short circuit current value is calculated, and the rated breaking capacity shall be selected more than the short circuit current value.

3.For the trunk line equipment that has working voltage exceeding 300V, the earth leakage breaker shall be used according to the general rule. However, when all of the branching circuits are earth leakage breaker, the trunk line equipment shall be breaker.

4.The fuse used as a breaker for power supply endures 1.1 times of the rated electric current, and the fuse shall melt down when 1.6 times or double of the rated electric current is conducted according to the classification of the rated electric current of the following table.

Table 200-1 Overload and short circuit protection using fuse

5.When the breaker for electric supply (MCCB) does not operate automatically with electric current of 1 times that rated current, and it operates with 1.25 times or 2 times of rated current, it shall operate automatically within the time according to the classification of the rated electric current of the following table.

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Table 200-2 Overload and short circuit protection using MCCB

(2)Protection of the branch circuit of electric light equipment is based on the following.

1.The protection of overload and the short circuit shall be performed.

2.The breaker shall be used as the protection instrument of the light and the outlet circuit. However, the divergence equipment of the following divergence circuit shall be earth leakage breaker.

-The circuit installed in wet room (including rest room, kitchen, dressing room etc.)

-The outlet circuit installed outdoor

-Outdoor light circuit

-The lighting duct circuit installed at the height which people touch easily

Article 201. Arrangement of light switches

The control by a switch is based on the below.

1.The height of the switch is 1,300mm as the general rule. But for the multipurpose rest rooms, it is 1,100mm or appropriate height in consideration of the convenience of institution user.

2.For warehouse, storeroom, bookroom etc. where a person is not always there, the switch is arranged near doorway by passage with indicating light.

3.An indicating light is attached to the switch of the equipment of which operation cannot be checked easily such as ventilation fan.

Article 202. Installation of electricity meters

As stipulated in Technical Regulation.

Article 203. Laying wires on the surface of equipment

When laying electric wire along the undersurface or the side of building parts, the following requirements shall be satisfied and it shall be performed not to damage the covering.

Cable fixed distance measuring points:

-The horizontal cable distance of supporting points of a cable shall be 2m or less

-The vertical cable less than or equal to 6 meters and in places you can not touch.

-With rubber cable must be less than or equal to 1 m, without damage to the cable sheath during installation.

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For devices that do not have specialized base for mounting directly on the wall to put more buffer as required insulation thickness.

Section 4 DISTRIBUTION BOARDS

Article 204. Requirement for installation of distribution boards

The specification of cubicle shall be satisfied with the specification which is stipulated in the Article 103. Because the main functions of the cubicle which place the distribution boards shall be secure prevention of electric shock and fire accident caused by the live parts of distribution boards.

Article 205. Place the Board between current-carrying parts

As stipulated in Technical Regulation.

Article 206. Locations for connecting input and output to distribution boards

In case that there are connection points in the rear of distribution boards, the structure of distribution boards shall adopt be hinge types in order to maintain from the front of boards or the minimum distance from the rear of boards to wall shall be more than the distance shown in the following table

in consideration of workability.

Table 206 Minimum distance between rear manipulation panel of distribution boards and wall

Article 207. Positions for wires passing to cubicles

When electric cables are passed through the penetrating part of the cubicle or metallic duct, itshall be necessary to install the insulating conduit which shown in the following diagram in the penetrating part, to avoid damaging the wire covering.

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Figure 207 Example of protection for wiring through penetrating parts

Article 208. Painting and signing

The provisions of this article shall refer to the Article 104.

Article 209. Equipment connected to distribution boards

In the three-phase system, if load balance of each phase becomes unbalance,voltage and current unbalance take place. As a result, the following defects may occur.

-The malfunction of open-phase protective relay which is used for the protection of induction motor

-In case of induction motor, the occurrence of overheat and burnout caused by voltage unbalance

In order to avoid those defects, it is preferable to operate the voltage unbalance within 3% of the voltage unbalance factor (VUF %) which is shown in the following formula.

The positive and negative sequencevoltage components of method of symmetrical componentsare obtained by resolving three-phase unbalanced line voltagesVab ,Vbc , andVca (or phase voltages) into two symmetrical componentsVp andVn (of the line or phase voltages). The two balanced components are given by

The a vector operator swings vector quantities through 120° in an anticlockwise direction a =1 120° and a2 =1 240°.

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