EARTHING SYSTEM

PRESENTATION BY…

PIC EARTHING TECHNOLOGY

ELECTRICAL EARTHING

ELECTRICAL EARTHING

GENERATION SIDE

TRANSMISSION SIDE

DISTRIBUTION SIDE

SUPPLIER SIDE CONSUMER ENDGenerators, Alternators, Switchgears

Switchyard etc.

Overhead Lines, Under Ground

Cables, Tr. Towers etc

Dist. Transformer, LT panel Earthing,,

MSP Earthing

Meter, Meter Box and other eqp.

Earthing

CONTENTS OF EARTHING SYSTEM

WHAT IS EARTH ?

WHAT IS EARTHING & EARTHING CODE ?

OBJECTIVES OF EARTHING.

BASIC CONSIDERATIONS FOR GOOD EARTHING.

TYPES OF AN EARTHING

STATUTORY PROVISIONS FOR EARTHING

TYPES OF EARTHING ELECTRODE .

LATEST TECHNOLOGY OF EARTHING .

WHAT IS PIC TECHNOLOGY ?

WHY PIC TECHNOLOGY ?

NOTIFICATION AND IE RULES RELATED TO EARTHING .

INSTALLATION OF PIC EARTH ELECTRODE.

WHAT IS EARTH?

The conductive mass of the earth, whose electric potential at any point is conventionally taken as zero.

Electrical means, Earth is a Low impedance return path of fault current.

The whole world may be considered as a vast conductor which is at reference/zero potential.In India, we refer to this as “EARTH”, while in USA, it is called “GROUND”.

ELECTRICAL PROPERTIES OF EARTH

The Earth does not have a homogeneous structure, but is formed of layers of different materials.

The resistivity of a given type of Earth varies widely and is very dependent on moisture content.

E.g.: Type of Earth Resistivity (ohm m ) Boggy Earth 2-50 Adobe Clay 2-200 Silt & Sandy Clay 20-260 Sand & Sandy Earth 50-3000 Peat Earth >1200 Gravel (moist) 50-3000 Rocky Earth 100-8000 Concrete (1:3) 50-300

Earthing is a connection done through a metal link between the Body of any Electrical appliance, or Neutral point, to the deeper Earth soil or electrode.

It covers the problems relating to conduction of electricity through Earth.

As a matter of fact, the Earth now rarely serves as a part of the return circuit but is being used mainly for fixing the voltage of system neutrals.

IS : 3043-1987 is the Indian Standard Code of Practice for Earthing.

WHAT IS EARTHING & EARTHING CODE?

OBJECTIVES OF EARTHING

Safety of Life/PersonnelBy operating Safety devicesBy limiting Step and Touch potentialSave lives during heavy S/C or abnormal fault

O/V Protection - Safety of ApparatusAgainst system Residual and HarmonicsAgainst abnormal Faults and Tripping

Improves Service ContinuityBy correct operation of electricity supply N/WVoltage Stabilization by common Earth

• EARTH IS A GOOD CONDUCTOR

• GROUND POTENTIAL IS ALWAYS ZERO

• PROTO TYPE EARTHING DESIGN IS SUFFICIENT

• EARTHING IS JUST BURYING CONDUCTOR

• EARTHING IS ONLY FOR ACHIVEING LOW RESISTANCE

VALUE

• USE OF COPPER FOR EARTHING WILL GIVE LOW

RESISTANCE

POPULAR ( MIS ) CONCEPTS ABOUT EARTHING

• EARTH IS A POOR CONDUCTOR

• NON HOMOGENEOUS

• CONDUCTORS BURIED IN SOIL HAVE COMPLICATED

SHAPE

• ACTIVE ONLY DURING FAULT CONDITIONS

• MOST OF THE ANALYSIS OF EARTHING IS BY

EMPIRICAL FORMULAE

REASONS WHY EARTHING PROBLEMS ARE COMPLEX

BASIC CONSIDERATIONS FOR GOOD EARTHING

Sensitivity & Selectivity of Ground Relaying1. Low resistance to Earth or Good conductivity. 2. Good Corrosion resistance.

Limitations of the magnitude of the E/F Current1. Ability to carry high current repeatedly.

Safe and Reliable long life system

Required degree of Surge Voltage Protection with arrestor.

TYPES OF AN EARTHING

SYSTEM EARTHING or NEUTRAL EARTHINGDeals with the Earthing of System Neutral to ensure system security and protection. Solidly Earthed

Here Neutral is directly connected to the Earth electrode / mat. E.g. Lighting Earth, Telecom Earth, DT Earthing

Resistance / Impedance Earthed Here Neutral is connected through a Resistance or an Impedance to the Earth Electrode / mat. E.g. Synchronous Generator Earthing

EQUIPMENT EARTHINGDeals with Earthing of Non-current carrying parts of equipment to ensure safety to personnel & protection against lightning.Function : Protection against Electric Shock, in Telecom Earth - reduce noise and interference, stabilize DC supply voltage and prevent electric shock

EARTHING IN ELECTRICAL

DISTRIBUTION NETWOTK

The main reason why Earthing is used in electrical distribution network is the SAFETY.

When all metallic parts in electrical equipments are grounded then if the insulation inside the equipments fails there are no dangerous voltages present in the equipment case.

If the live wire touches the grounded case then the circuit is effectively shorted and fuse will immediately blow. When the fuse is blown then the dangerous voltages are away.

STATUTORY PROVISIONS FOR EARTHING

The value of any earth system resistance shall be such as to conform with the degree of shock protection desired.

Permissible values of earth resistance

a) Power stations - 0.5 ohms

b) EHT Stations - 1.0 ohms

c) 33KV SS - 2 ohms

d) DTR Structures - 5 ohms

e) Tower foot resistance - 10 ohms

TYPES OF EARTHING ELECTRODE

Conventional Earthing

+ Plate Type Earthing+ Pipe Type Earthing

Earthing in modern trend+ Pipe in Pipe Earthing+ Pipe in Flat Earthing

Latest Technology + PIC Earthing Technology

CONVENTIONAL METHOD OF EARTHING

Plate type Earthing: Generally for plate type Earthing people are using Cast

Iron plate of size 600mm x 600mm x 12mm OR Galvanized Iron plate of size 600mm x 600mm x 6mm OR Copper Plate of size 600mm x 600mm x 3.15mm .

Then buried at the depth of 8 feet in the vertical position and GI strip of size 50mm x 6mm bolted with the plate is brought up to the ground level.

These types of earth pit are generally filled with alternate layer of charcoal & salt up to 4 feet from the bottom of the pit.

CONVENTIONAL METHOD OF EARTHING

Pipe type Earthing:

Generally for Pipe type Earthing people are using GI pipe [C-class] of 75 mm diameter, 10 feet long welded with 75 mm diameter GI flange having 6 numbers of holes for the connection of earth wires.

Then inserted in ground by auger method.

These types of earth pit are generally filled with alternate layer of charcoal & salt or earth reactivation compound.

MAINTENANCE OF EARTHING

The following maintenance schedule is mandatory at each of the substations.

Sr.No Item Periodicity

1. Periodical Check / Test of Earth Electrodes @ Half yearly

2. Periodical visual examination/inspection of all earth electrode connections & condition.

Weekly

3. Watering of earth pits through a pipe where fitted along with it.

Weekly

4. Measurement of earth resistance of individual earth pits.

@ Half yearly Not exceed 2 Years

5. Measurement of combined earth resistance at all the earth pits.

@ Half yearly Not exceed 2 Years

6. Checking of interconnections betweens earth pits and tightness of bolts and nuts.

@ Quarterly

After 3 to 5 years what is happening

All Plates OR Pipes used get rusted and corroded due to oxidation process under the soil.

Once rusting & corrosion start its resistance [ohm] value increased and so many issues start in electrical distribution system.

e.g. voltage fluctuation, neutral floating and unbalance current flow from circuits.

WHAT ARE OUR FINDINGS ?

After lots of concentration on these types of issues we thought that there must be improvement in two areas.

1. Material used as earth electrode should have very high rust resistive property and good current conductive property.

2. Total contact area of electrode with earth should be as possible as maximum.

As a result of this thought we tried to develop special design of earth electrode by which we can get both the benefits, as PIC.

WHAT IS PIC Technology?

The result of more than 24years of R&D Pipe In Cage Technology The final solution for any Earthing

related problems We had developed the electrode with

alloy of Nickel and Stainless Steel having very high rust resistive property and good current conductive property.

COPPER V/S STAINLESS STEEL IN ELECTRICAL USE

The permanence of Copper in most soils, its resistance to chemical attack, and its inherent low resistance, brings it into widespread use throughout the Electrical industry around the world.

However, there are certain soils where it is inadvisable to use Copper such as in Tidal land, Salt marshes, Swamps and land filled with ashes, coke breeze and like materials.

Pipe in cage Electrode have a high resistance to both atmospheric and soil corrosion as it made from Stainless Steel with Nickel.

WHAT PIC TECH INCLUDES

Variety of products

E1 Model – For residential use

E2 Model – For commercial use

E3 Model – For industrial use

E4 Model – For Transformer Neutral in GTD

High degree of flexibility

New Technology for better Safety and Modern Design

REASONS FOR SELECTING PIC

PIC electrode is made from unique metal with special alloys as homogeneous material, no bimetal contacts.

PIC electrode is free from galvanic attack.

PIC electrode is having very high rust resistive property and good current conductive property.

PIC electrode has maximum utilization of available surface area.

PIC electrode provides theft proof design.

PIC electrode is available in wide range in different sizes to suit all types of need from common man to foreman.

REASONS FOR SELECTING PIC

PIC electrode is having large surface area compare to conventional electrodes.

PIC electrode has capacity to carry high current repeatedly.

PIC electrode is easy to install and require less space. PIC electrode provides fast dissipation of any fault /

static current due to large surface area, no corrosion and maintaining require moisture contents

Eco friendly earth enhancer compound as SFC. Cost effective. Ensures protection in any season. Long life.

Typical Application of PIC Electrode

Where the chemical composition of the soil reacts more unfavorably than copper as per conditions described above

Where the earthed item needs to be protected against galvanic attack and corrosion, eg. lead sheathed cables, steel poles, etc.

SUPPORT FILLING COMPOUND

It is a conductivity improver compound. It is a specially developed compound having high conductivity, rust resistance property, absorbing & retaining the moisture for a long time.

It reduces the soil resistivity and helps in faster dissipation of fault current.

It is also helpful to control fluctuation of OHMIC value

INSTALLATION OF PIPE IN CAGE

Augur / Drill / Bore a hole of 8-10 Inch in diameter at a place where Earthing is to be done up to appropriate length of PIPE IN CAGE Earthing Electrode.

Put the electrode in vertical positions in the pit with the connection terminal on the top. It is recommended to fill support filling compound surrounding PIPE IN CAGE Electrode mixed with proper water pouring simultaneously.

Normally 1 bags of support filling compound is recommended for our PIPE IN CAGE Earthing Electrode but in some case i.e., Rocky Area or filled soil area bag can be varies.

Make joint with suitable copper wire/Stainless steel strip or G.I. wire/strips carry for Earthing from your equipment etc. up to the Earthing terminals provide on the top of the PIPE IN CAGE Earthing Electrode.

Put the chamber with the cover over the PIPE IN CAGE Earthing Electrode & apply petroleum jelly on the exposed part of PIPE IN CAGE Earthing Electrode i.e., terminal.

Do proper water pouring up to 6-7 days after Installation

SOME VIEWS OF EARTHING AT SITE

Notification 10. Ch-3 Clause 3.4 to 3.6

Clause 3.4

The grounding provided for the equipment and lines and Earthing grid for substations shall be in accordance with IS: 3043 - Code of Practice for Earthing.

Clause 3.5

It is not enough to have a good earth connection at the time of construction, but it should also be maintained in a sound and healthy state at all times. The Licensee shall take all necessary steps for testing of the same and maintain the record of each test in accordance with Sections- 32, 51, 61, 62, 67, 69, 88(2) and 90 of the Indian Electricity Rules, 1956.

Notification 10. Ch-3 Clause 3.4 to 3.6

Clause 3.6

Leakage current means difference between phase current and return path. The Licensee shall take necessary steps to measure leakage current at various points in the system.

In Case of LT Section Earth resistance of Mini Section Pillars are measured and if found high values. Earthing system is replaced or reactivated by Mains Department.

Electrical Earthing is the most important though most neglected part of the Electrical Safety of personnel and property.

EARTHING

SAVE ME

Thank Q

ELECTRICITY IS THE BEST FRIEND AND WORST ENEMY.

System Grounding (Equipment Protection)

Equipment Grounding (Personal Safety)

Earth as Equipment Grounding Electrode

CORRODDED EARTHING CONNECTIONS