PROBLEMAS, CAUSAS Y SOLUCIONES

B3.1 INSTALLATION OF LIGHTING SYSTEM AND LUMINAIRES

B3.1.1 Pendant

Tube pendant shall comprise a dome cover and a biscuit ring and a piece of screwed steel conduit of suitable length to give the required mounting height of the luminaire.

Plain pendant shall comprise a ceiling rose and a cord-grip lampholder connected by a flexible cord having a suitable length to give the required mounting height of the lamp shade.

B3.1.2 Luminaire Mounted on Pattress

When a luminaire is not provided with facility for a surface cable entry, the luminaire shall be mounted on pattress. The cable shall then enter the luminaire from the rear through a slot and a hole formed in the pattress.

B3.1.3 Ceiling Rose

Ceiling rose shall not be used for the attachment of more than one outgoing flexible cord or cable unless it is specially designed for multiple pendants.

B3.1.4 Cable in Enclosed Luminaire

Cables within an enclosed type luminaire shall be of heat resistant type. Cables entering the luminaire shall be protected by heat resistant insulating sleeves. The sleeves within the luminaire shall be extended to a distance of 150mm outside the luminaire.

Heat resisting cables shall be selected in accordance with the appropriate tables given in IEC 60364.

B3.1.5 Stroboscopic Effect

Luminaires, other than those using tungsten filament lamps or fluorescent lamps with electronic ballast, installed over rotating machinery, shall be arranged so that at least two luminaires connected to different phases are used to illuminate the moving parts of the machinery. Alternatively where different phases are not available or the use of which is impracticable, separate tungsten filament lamps shall be used in addition to gas discharge lamps to eliminate the stroboscopic effect.

B3.1.6 Painting

Unless otherwise specified, lighting equipment and luminaires other than those indicated to be self-finished such as stainless steel, anodized aluminium, etc, shall have factory-finished.

Metal parts such as cover plates for adaptable boxes, blanking plate for any boxes and conduit pendants, etc. shall be painted white or a suitable colour to match the interior finish of a particular location.

B3.1.7 Special Requirements for Outdoor Luminaires

Outdoor luminaires shall be able to withstand the weather. Metal work should be protected against corrosion, and parts which have to be removed for access to the interior shall be provided with proper gaskets to restrict the entrance of moisture and dirt. Mounting brackets shall be heavily galvanized and stainless steel or galvanized bolts and nuts shall be used.

The adjustment bolts and nuts of a luminaire which is mounted on high level shall be captive to prevent accidental loss during servicing. Safety chains shall be provided to hold the luminaire from falling. A luminaire installed in a location within hand reach shall be of robust construct, fitted with an impact-resistant transparent or diffusing front panel, and shall have secret key fixings for the panel to the body of the luminaire. Where necessary, wire guards shall be fitted over the front panel to give extra protection.

B3.2 INSTALLATION OF WIRING ACCESSORIES

Wiring accessories, including lighting switches, socket outlets and domestic type switches for electrical appliances, shall be designed for flush mounting.

Where surface wiring installation is specified, wiring accessories shall be fixed onto moulded boxes or pattresses. In conduit installation, they shall be fixed onto moulded, galvanized steel or cast iron boxes.

Where a waterproof or flameproof configuration is required, wiring accessories shall be mounted as the particular circumstances demand.

The front plate of a switch or socket outlet shall be labelled in accordance with Sub-section A3.3.

B3.3 INSTALLATION OF DOMESTIC SWITCHES

B3.3.1 General

Switch for domestic and similar purposes shall be mounted at a height of 1350mm above finished floor level unless otherwise specified.

Section B3

B3.3.2 Lighting Switch

When lighting switches are mounted adjacent to one another, they shall be grouped in a single enclosure (multi-gang box) and shall share a common switch plate, subject to a maximum of three lighting switches per single-gang plate.

Lighting switches installed adjacent to a door shall be located on the handle side of the door, and shall be as near to the door as practicable. B3.3.3 Time Switch

Time switch shall be housed in a factory or purpose made metal enclosure provided with a removal cover of durable clear plastic material.

B3.3.4 Application in Bathroom

No switch shall be installed inside a toilet or a room containing a fixed bath or shower. All control switches shall be located immediately outside the room.

B3.4 INSTALLATION OF SOCKET OUTLETS

B3.4.1 General

Socket outlet intended for supplying a fixed or stationary appliance shall be located as near as possible to the appliance.

Socket outlet shall be mounted at a height of 1350mm above finished floor level in kitchens, sculleries, ironing rooms and the like. In other locations, they shall be mounted at 300mm from finished floor level, 75mm from surface top measured from bottom of socket outlet or as specified.

B3.4.2 Shaver Supply Unit

The complete unit shall be enclosed in a galvanized metal box for flush mounting, or a galvanized cast iron or plastic surface box for surface mounting.

B3.4.3 Socket Outlet at Hazardous Area

The installation of socket outlets in hazardous areas should be avoided as far as possible. Where it is absolutely essential to install a socket outlet in such area, the socket outlet shall be type ‘e’ - increased safety conforming to IEC 60309-3 and shall be controlled by a sparkless switch. The socket outlet shall be interlocked with the plug so that removal or insertion shall not be possible unless the controlling switch is in the OFF position. The plug shall have shrouded pins and the design of the pin contacts shall be such as to guard against development

of hot spots or sparking. Requirements for wiring installation in hazardous areas are specified in Sub-section B7.4.

B3.4.4 Socket Outlet of Surface Conduit System

In plant room, switch room or similar area where surface conduits are installed, socket outlets shall be metalclad or bronze front plate.

B3.4.5 Socket Outlet for Different Voltage System

Socket outlet and plug for one voltage system shall not be interchangeable with those for use at other voltage and/or frequency systems in the same installation.

B3.4.6 Application in Bathroom

Shaver supply units complying with BS EN 60742 can be installed inside a room containing a fixed bath or shower and inside a toilet. Socket outlets inside such a room, if so required under the contract, shall be installed in accordance with requirements of Code 26A(3)(j) of Code of Practice for Electricity (Wiring) Regulations.

B3.5 INSTALLATION OF MEASURING INSTRUMENT

B3.5.1 Mounting of Current Transformers Associated with Watt-hour Meter Current transformers, if required to be associated with a watt-hour meter, may be mounted inside the meter chamber, or in a separate current transformer chamber, as dictated by the circumstances of each particular job. When current transformers are mounted in the meter chamber, separate partitioned compartments with separate front access covers for the current transformers and meters respectively shall be provided. Suitable engraved labels shall be fixed on the covers to identify the installed equipment therein.

B3.5.2 Identification of Instrument

Each measuring instrument shall be identified by means of a label fitted under the associated instrument. This label shall denote the function of the circuit connected to the meter.

B3.5.3 Mounting Position of Selector Switch

Selector switch for ammeter or voltmeter shall be mounted immediately below the meter with which it is associated.

Section B4

SECTION B4