CB204 ELECTRICAL SERVICES

CB204ELECTRICAL SERVICES presentation 3

JAB.KEJURUTERAAN AWAMDIP . KEJURUTERAAN PERKHIDMATAN BANGUNANPN.NUR ASHIKIN BT LAKMANDPB2CNamaNo marikNAFZIAH B SALEHUDINO3DPB13F1030NUR ANIS RAMIZAH B HAMZAH03dpb13f1033Nurul izni bini ramli03dpb13f1069Nur farrahin b mustafa03dpb13f1081TOPIC 7EARTHINGEarthing in electricity is the process of installing a protective earth wire into the surface of the earth to limit chances of an electric shock occurring, in electrical objects with insulation faults. In addition to limiting electric shocks, earth connections are important in electric gadgets, which require surge suppression and protection from electromagnetic interference.Earthing system is designed followed by electrical system required and the application.It have different earthing system for each electrical application such as consumer power supply ,substation ,offshore, ships, underground system ,generator and over head system.

DIFINATION OF EARTHINGIMPORTANCE OF EARTHING IN ELECTRICAL SYSTEMEarthing or grounding means to connect any electrical appliance, machine or equipment at zero potential of genaral mass of earth with wire connected with the earth electrode burried in the earth at the moistened place.Earthing is as important as the fuses in the wiring circuits i.e.in the case of short circuits or over loads, the heavy current flows through the wires and fitting etc. which melts the fuse wire and stops the flow of current in the circuits, thus save the whole circuit from being damaged.Similarly, when any live or phase wire touches the metal part of the fitting, appliance, machine or equipment, the current passes through the earth wire, if the appliance, equipment or machine etc. are connected with proper earth connnection, blows the fuse atonce and saves the operator from getting shock. Thus to avoid these dangers, all metal parts of the fitting, appliances, equipment, machines etc are earthedTYPES OF EARTHING SYSTEMSTT SYSTEMIT SYSTEMTN-SSYSTEMTN-CSYSTEMTN-C-SSYSTEMTT SYSTEMThis system normally used for consumerpower supply .No earthing system provided by power distributor.The owner must install the earthing protection by their own connection to the earth.They must installing a suitable electrode and safe arrangement for which they are responsibility to theirinstallation

The neutral and earthing conductor must be separately through theinstallationbecause power distributor only provide the supply neutral or protective conductor for the connection to consumer.

The advantage of this system is it clear from the noise of high or low frequency,not have risk of neutral broken or failure and suitable for special application like telecommunication.TT system is suitable for premises where all AC power circuits are residual current device (RCD) protected.

IT SYSTEMThis system is similar with TT system but totally different in earthing supply.The distributor system not have any connection to earth or it have only a high impedance connection.It mean the usual protection is not effective for this system.

This type is not for consumer power supply.It special for power distributor such as substation orgeneratorarea.TN SYSTEMThis system has the neutral of power supply with connection of earth only at one point to the source.the consumers earthing terminal is usually connected to the metallic Armour of the distributors cable into the HV / LV transformer.

It is commonly used for underground power supply to the premise or factory from the distributor substation to customer substation.This earth terminal is connected by the supply protective conductor (PE) back to the star point (neutral) of the secondary winding of the supply transformer, which is also connected at that point to an earth electrode.TN-S SYSTEMThis system has the neutral of power supply with connection of earth only at one point to the source.the consumers earthing terminal is usually connected to the metallic Armour of the distributors cable into the HV / LV transformer.

It is commonly used for underground power supply to the premise or factory from the distributor substation to customer substation.This earth terminal is connected by the supply protective conductor (PE) back to the star point (neutral) of the secondary winding of the supply transformer, which is also connected at that point to an earth electrode.

TN-C-S SYSTEMThis system has the supply neutral conductor of a distribution main connected with earth at source as protective multiple earthing (PME).The supply distributor neutral conductor is also used to return earth fault currents from the consumer installation back to the source with a safely manner.

The power supply distributor will provide a consumers earthing terminal which is linked to the incoming neutral conductor.This combined earth and neutral system called the protective and neutral conductor (PEN) or the combined neutral and earth conductor (CNE).

TN-C SYSTEMThis system is not familiar or unusual for earthing system.It a combined PEN conductor fulfills the functions of both a PE and an N conductor.The PEN conductor is the sheath of a cable and therefore is concentric with (totally surrounds) the phase conductor(s).

For wiring or cabling purpose,the suitable material is uses mineral insulated cable, the metallic copper sheath being the combined neutral and earth conductor.Normally this system used for ships or offshore platform earthing system.RCD protected is not function properly for this system.THINGS NEEDFOREARTHING:

All structuremetalin systemwiring(thatnot bringingcurrent) likemetallic coating,shieldconduit,canal,trunk,catenarywireand so on.

Structuremetalthat isexposed to allequipmentsincluding thosenot related toelectriclike waterpipe,house frameworkand so on.

Asecondarycausecoilforconverter.THE INSTALLATION METHODOur organization is engaged in providing a comprehensive range of Earthing Electrodes that includes various models of earthing solutions to suit residential, industrial and commercial requirements with Copper and GI electrodes.

Our range of products is widely acclaimed for features like reliability in performance, high conductivity and less maintenance.

We are equipped to provide consultation services and Earthing solutions to variety of business and industry i.e. engineering industry, Hospitals, Shopping malls, Airports, Solar systems, Substations from drawing board stage to commissioning.SEKIAN TERIMA KASIH