Maintenance Free Earthing System - Doksun Power To provide an alternative path for induced current and minimize the electrical noise in cables. The earthing system consists of, conductive

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Maintenance Free Earthing System

DOKSUN R

C P R Ic e n t r a l p o w e r r e s e a r c h i n s t i t u t e

9001 : 2008

DOSKUN POWER PRIVATE LIMITEDSurat, Gujarat, (India)www.doksunpower.com

www.doksunpower.com1Page |

Earthing is of utmost importance for safety of factories, plants, equipment, property and human beings as well as animal life. In the absence of a well –designed effective earthing system, earth fault conditions may lead to tremendous loss of property and lives. Earthing is fundamental to most of the practices to achieve safety. The earthing system must provide a direct route to the soil for fault current whilst minimizing touch and step potentials. The secondary function is to help mitigate disturbances and serve as a common voltage references for sensitive electronic equipment. However, with greater use of sensitive electronic equipment, particularly in Software Industries and Telecom Sectors, there is a growing awareness of the importance of the secondary function of the earthing system. This is leading to a consensus of opinion that the earthing system must be designed as an overall system such that it fulfills the safety and performance requirements.

The main factors influencing the choice of earthing are as follows :

9 To ensure safety of the property and life from hazards of electric shock and electric fires.

9 To ensure that system voltages on healthy lines remain within reasonable limits under fault conditions,

i.e. lightning, triking ground faults thereby preventing insulation breakdowns.

9 Even under conditions of a HV line breaking and falling on a LV system, an efficiently grounded LV

system will hold the system neutral close to the ground potential thus limiting the over-voltage.

9 To provide a low impedance path to facilitate the satisfactory operation of protective devices under

fault conditions.

9 To minimize arching burn downs as in an earthed system arching fault would build up transient, in

ground path thereby eliminating any high frequency voltage oscillations following each arc initiation

or re-strike, providing an easy means of detecting and tripping against phase to earth arching fault

breakdowns.

9 To provide an equipotent platform on which electronic equipments can operate.

9 To provide an alternative path for induced current and minimize the electrical noise in cables.

The earthing system consists of, conductive material above ground ( bonding, conductors etc. ) Metal electrodes within the soil and the surrounding soil itself. Each of these contributes towards the overall impedance value. However, it is important to recognize that the characteristics of the soil, strongly influence the earthing system performance. The most important characteristics of the soil is its resistivity, which is measured in ohms. An earth pit may comprise of several large pipes inserted vertically into the soil. They are bonded together and surrounded by low resistivity and high conductive material.

EARTH ELECTRODES

The earth electrode is the main component of the earthing system, which is in direct contact with the ground and, thus provides a means of releasing or collecting any earth leakage currents. In earthed systems, it will normally be required to carry quite a large current for a short period and so will need to have adequate mechanical and electrical properties to continue to meet the demands on them over a relatively long period, during which actual testing or inspection is difficult. The material should have good electrical conductivity and should not corrode in a wide range of soil conditions.


Requirements of a Good Earthing System ( as per RDSO guidelines)

The function of the earthing system is MULTI FOLD -

5 To provide a low enough impedance path, via the earth conductors, back to the supply source so that in the event of a fa ilure to earth of a live conductor, sufficient current will flow safely along a predetermined route to enable the circuits protective device to operate.

5 To limit the potential rise on all metalwork to which humans and animals access, to a safe value under normal and abnormal circuit conditions. The bonding together of all normally exposed metalwork (like gas, water, central heating, pipe work, etc.), And the connection of that bond to the earth terminal, will prevent the possibili ty of a dangerous potential difference arising between adjoining pipe work under both normal and abnormal conditions.

5 Conductors of sufficient dimensions capable of withstanding high fault currents with no evi-dence of fusing or mechanical deterioration.

5 Lower earth resistance ensures that energy is dissipated into the ground in the safest possible manner.

5 Lower the earth circuit impedance, the more likely that high frequency lightning impulses will flow through the ground electrode path, in preference to any other path.

5 High Corrosion Resistant – The choice of the material for grounding conductors, electrodes and connections is vital as most of the grounding system will be buried in the earth mass for many years. Copper is by far the most common material used. In addition to its inherent high con-ductivity, copper is usually cathodic with respect to other metals in association with grounding sites, which means that it is less likely to corrode in most environments.

5 Mechanically robust and reliable.

Considering all the above facts and requirements, “DOKSUN POWER PRIVATE LIMITED.”, after a consistent research and development with gaining experience in the field of safe Earthing, after more than a decades work developed a new safe and maintenance free chemical earthing system design and technology, under the make name “DOKSUN“, (the name we will use onwards) which not only takes care of all the above parameters.Unlike the conventional earthing system, these systems do not require to dig large pits for placing big plating systems and use salts, charcoal etc, and relative to this they have a very long corrosion free life and are nearly maintenance free for years to come.

Galvanized steel, Copper, and Stainless steel are generally the preferred material. Aluminum is sometimes used for above ground bonding, but most of the standards forbid its use as an earthing electrode, due to the risk of accelerated corrosion. The corrosive product which is the oxide layer on the electrode is non-conductive in nature, so could reduce the effectiveness of the earthing.


Again, here the “DOKSUN” make Earthing Electrode serves the purpose effectively. In this there is one pipe of given diameter and heavy flat strip (patti) of suitable width to dia of pipe as shown in our brochure. The heavy flat strip is placed inside the bigger dia. pipe and the annular space between the two is filled with a special type of conductive, non-corrosive Backfill Compound. The completed Earth Electrode is heavily electroplated externally as per UL standards to enhance the life of the Electrode susceptible to corrosion (depends on the soil conditions). The water is used once during installation and fitting, and then the moisture is retained by the compound, throughout its life eliminating the use of water in regular intervals. (as per weather conditions)

Once the earthing system is properly installed, our “DOKSUN” make earthing electrode will provide a very good earth resistivity value compared to the conventional earthing and since our earthing system resists corrosion, therefore the earth resistance value remains same without major fluctuations. When installed properly as per our guidelines our earthing systems provide better life and result, than conventional types for many years to come without fail.

It is important to note that the characteristics of the soil play a major role in determining the earth resistance value and the factors that determines the characteristics / resistivity of the soil.

The earth resistance value (Ohmic Value) of an earth pit depends on the soil resistivity.

Our Earthing System and installations

FACTORS DETERMINING SOIL RESISTIVITY

Physical Composition: Different soil composition gives different average resistivity. Based on the type of soil, the resistivity of clay soil may lie in the range 4 – 150 ohm /mtr whereas for rocky or gravel soils, the same may be well above 1000 ohm /mtr.

Method of Old type General Electrical Earthing World Wide

The general pipe earthing practice followed most of the world over is that, a perforated GI/CI pipe with a copper wire is placed vertically inside the earth and layers or mixture of sand, salt, charcoal etc. is put around this pipe used as an electrode. On top of this pipe electrode, a funnel is provided for watering purposes, so that enough moisture is maintained around the electrode periodically in order to conduct, since moisture is very much essential for any type of earthing to work and function properly.

When water is poured from top of the electrode through the funnel, the water spreads out through the hole, and the surrounding salts, charcoals, etc. comes in through the hole and the hole is clogged, the use of coal salt mixture also helps in fast corrosion of the old system pipe electr ode. The result is that the corrosion of the wire and the pipe starts inside and outside simultaneously and the copper wire with the pipe is eaten up within one or two years and the purpose of maintenance free earthing is diminished.

The use of water, salt etc. is required for lowering the soil resistivity, as low resistive soil is good for earthing purposes. However, it is equally true that “lower the soil resistivity, better the earthing BUT lowering the soil resistivity by using coal/salt mixture also increases the higher rate of corrosion.”


Effect of Moisture on Soil Resistivity: Moisture has a great influence on resistivity value of soil. The resistivity of a soil would be determined by the quantity of water held by the soil and the resistivity of the water itself. In other words conduction of electricity in soil is through water, which means that phenomenon is electrolytic. It is to be noted that resistance drops quickly to a more or less a steady minimum value at about 15% moisture content and thereafter, increase in the wetness of the soil has little effect on soil resistivity.

Effect of Dissolved Salts in Water: Since the resistivity of the soil depends on resistivity of water, which in turn depends on amount and nature of salts dissolved in it. It is to be noted that quite a small quantity of dissolved salt can reduce the resistivity considerably. A small quantity of salt 1 to 2% by weight of moisture drops the resistivity of soil by 80%, as the concentration is increased; the moisture tends to a steady low value.

Effect of Temperature on Soil Resistivity: Soil resistivity increases sharply with decrease in temperature below 0°C. At -15°C the earth resistance was compared to be over ten times at 0°C. This signifies the need of burying the electrodes sufficiently deep below the frost level especially in regions where low temperature below 0°C is experienced.

Effect of Grain Size and its Distribution: Grain size, its distribution and closeness of packing are also contributory factors, since they control the manner in which the moisture is held in the soil.

Effect of Seasonal Variation on Soil Resistivity: We have observed that presence of moisture in the soil is the most important element in determining its conductivity. Conditions, which increase or decrease the distribution of the moisture content in the soil result correspondingly in an increase or decrease of the conductivity. It is thus anticipated that resistivity of the earth will undergo variation with seasonal changes. Field experiments have indicated in seasonal variation the resistance variance nearly up to 60%.

Effect of Current Magnitude: Soil resistivity in the vicinity of ground electrode may be affected by current flowing from the electrode into the surrounding soil. The thermal characteristics and the moisture content of the soil will determine if a current of a given magnitude and duration will cause significant drying and thus increase the effect of soil resistivity. Therefore at the time of requirement one should keep significant margin and go for a higher capacity electrode than to choose for a lower capacity.

“However, it is important to recognize the fact that characteristics of soil play a major role in determining the earth resistance value, and as per Indian standards, in high resistive soil it requires more than one earth electrode installed and connected in parallel to bring down the earth resistance value within safe limits.”


STEP BY STEP INSTALLATION METHOD OF “DOKSUN” MAKE PIPE ELECTRODE EARTHING SYSTEM

Normal Soil

Rocky Soil

Augur / Drill / Bore a hole of 8/10 inches in diameter to a suitable depth of 2 or 3 meters length

Mix backfill compound nicely with dug out soil.

Sieve any big size material from soil as these decrease the connectivity in the soil.

Throw handful of compound soil mix into pit.

Remove plastic sleeve carefully from electrode.

Place electrode at centre of pit.

Start refilling empty space around electrode with backfill compound in small quantities.

Then pour some water and poke the pit with a long wooden rod, to allow trapped air to es-cape.

In this manner gradually continue refilling process till electrode is buried in the pit, up to the green patch painted or the green cap on the top portion of electrode.

Ensure that pit is not watery.

Pack electrode with compound nicely and tightly, so that it stands firmly in pit.

Pour a few buckets of water in and around the pit everyday for 3 days for system to set.

Do not hammer the earthing electrode.

After 3 days connect the electrode with the application.

Dig a trench of 3’and 11’deep;

fill the entire pit with black cotton soil or normal soil,

pour enough water so that pit is full with water,

Leave it for three days so that soil soaks up the water.

Top up the pit with soil & fill the water if necessary.

After two or three days this pit is sturdy and ready for earthing purpose.

Now earthing electrode can be installed as per installation method for normal soil given earlier.

PROPER INSTALLATION METHOD : The Earthing Electrode can be installed by any one of the following methods depending on the soil condition.

Normal Soil:

Make a bore of 8” to 10” in diameter manually up to the electrode length (2 Mtr or 3 Mtr). Put a little quantity of Back Fill Compound (a layer of min. 3 to 4 inch) inside the pit and drop the electrode exactly in the center of the pit. Now mix the soil that has been dug out with the B.F.C. (conductive and non corrosive mixture) eliminating the stones, rocks and other bigger shapes. Now pour the above mixture in small quantity in to the pit followed by water and remove the trapped air inside the pit by poking a rod in to the mixture repeatedly. Repeat the above exercise till the pit is completely filled up. Pour sufficient water so that mixture is in paste /mud form. Al low the pit to stand for 24 hrs. and absorb the water and becomes compact. Test the earth pit and connect to the electrical circuit. Avoid excess watering. Do not hammer the earth electrode.


Sandy Soil: Make a big pit of 06’ x 06’ and 11’ deep; fill the entire pit with black cotton soil or normal soil, pour enough water so that pit is full with water, leave it for three days so that soil soaks up the water. You will notice that soil level has gone down and again top up the pit with soil & fill the water. Now after two or three days this pit is ready for earthing purpose and our earthing can be installed there by above described normal method, that will definitely give you a very good earth resistivity value. However, if the pit is filled with BFC mix soil then that will show better earth resistance value. These types of installations may needs regular watering after certain intervals that depends on the characteristics of the soil described in the “Factors determining the soil resistivity”. It is to be noted that more than one earth electrode may be required to be installed and connected in parallel to bring down the earth resistance value with in safe limits.

Semi-Rocky Soil:

If enough soil is there then earthing can be done by normal method otherwise that can be done by making a big pit as in case of sandy soil. Ours is a corrosion resistant, long life and almost maintenance free earthing system in normal soil conditions & if installed properly it will give better earth resistivity value than conventional earthing system throughout there life. It is a Fit & Forget earthing system. However, these types of installations may needs regular watering after certain intervals that depends on the characteristics of the soil described in the “Factors determining the soil resistivity”. It is to be noted that more than one earth electrode may be required to be installed and connected in parallel to bring down the earth resistance value with in safe limits when done on ROCKY SOIL.

Measuring the Impedance of Earth Electrode Systems

Measurement of the Ohmic value of a buried electrode is carried out for two reasons: -

• To check the value, following installation and prior to connection to the equipment, against the design specification.

• As part of routine maintenance, to confirm that the value has not increased substantially from its design or original measured value.

BACK FILL COMPOUND ( BFC )

In all cases, the backfill medium should be conductive but non-corrosive in nature, be of a relatively small particle size and should, help to retain moisture for a considerable period of time. More often than not the previous excavated soil is suitable as a backfill, but should be sieved to remove any large stones and rubbles and placed around the electrode, taking care to ensure that it is well compacted. The soil should maintain a pH value between 6.0 (acidic) to 10.0 (alkaline). Normal stiff clay is not a suitable backfill material as, if heavily compacted; it may become almost impervious to water and could remain relatively dry. It may also form large lumps, which do not consolidate around the electrode avoiding to make good contact with soil to the electrode itself.

BFC, (back fill compound) is a specially developed compound, which is capable of absorbing and retaining the moisture for a long time, it reduces the soil resistivity, it helps in faster dissipation of fault current, least fluctuation of Ohmic value and it eliminates the use of Salt, Charcoal etc. around the Earthing Electrode. It has low solubility, hence is not easily washed away, and has a low resistivity (approximately 5-10 Ohm-meters in a saturated solution). It is virtually neutral, having a pH value of between 6.2 and 6.9. should not generally cause environmental difficulties in use.


It assists in maintaining a relatively low resistivity over a long period of time, in areas where salts in the vicinity are dissolved away by water movements (rainfall etc.). However, the fact that the material is not easily dissolved will moderate the benefits achieved, since it will not permeate far into the ground. This means that the beneficial effect will be localized for say an area excavated around a buried electrode. This in turn means that the reduction in the resistance value of the electrode will not be dramatic but will be reasonably sustainable. Materials, which should not be used as backfill Compound, include sand, coke-breeze, cinders, and power station ash, as many of them are acidic and corrosive in nature.

“DOKSUN” MAKE BACK FILL COMPOUND”

It is always placed around the earth electrode in the earth pit to improve the conductivity of earth electrode and ground contact area. The greatest advantage to use the product is that it eliminates the use of coal and salt mixture and will not shrink and crack with time. Our “DOKSUN” Make back fill compound (earth enhancement material) is :

a. A homogeneous mixture based upon Bentonite of naturally occurring hygroscopic conducting compounds. It is chemically activated and modified for earthing/grounding needs, which increases the earthing system efficiency.

b. A hygroscopically natured and swells considerably removes entrapped air thereby creating a strong connection in between the electrode and the soil.

c. Non-toxic, non-reactive, non-explosive and non-corrosive in nature and thermally stable which makes “DOKSUN” make BFC ideal for earthing / grounding purposes.

d. A superior conductive material that solves the toughest earthing/grounding needs, improves the effectiveness regardless of soil conditions. “DOKSUN” make BFC is an ideal material to use in areas of poor conductivity, high corrosion and frequent moisture fluctuations in the soil i.e. rocky grounds, saline coastal areas, sandy or gravel soil, and mountain ranges.

e. Highly swell special type clay mixed with other minerals of different properties can bind water to a great extent. The main principle of “DOKSUN” make BFC is to bind the BFC with water to the sandy or rocky soil or any type of soil and to sheath the electrode with it. This sheathing is conductive, non-corrosive and enlarges the surface area of the electrode to conduct effectively, thus enhancing the efficiency of earthing/grounding system.

f. Product Use – As the BFC used has swelling properties, it swells to about 25% by volume, and this swelling property is always neglected by the electrode installing people. In the course of installation it is very necessary to provide plenty of water into BFC, about 100 ltr of water per bag, for successfull swelling of BFC it is necessary to provide so much water, after which it holds and retains moisture for lifelong working. In absence of proper water the BFC does not swell much and powder stones are formed and so the air pockets also, as a result poor conductivity in the electrode is observed in form of high resistance value, etc. Therefore at the time of installation it should be made sure about the availability of water. Once installed by proper usage of water you will get very low ohmic value guaranteed. After proper swelling the whole mass is tightly packed inside the earth pit and no air gaps are left. This stage is very helpful in all round conductivity of earthing electrode.


1. IDENTIFICATION OF THE SUBSTANCE / PREPARATION AND OF THE COMPANY / UNDERTAKING

Product name : DOKSUNProduct code : GIM Use / description of product: Granular Solid. No significant hazard.

2. COMPOSITION / INFORMATION ON INGREDIENTS

INGREDIENTS: Bentonite Hydrous aluminium silicates Calcium Carbonate Carbon Powder

Technical Datasheet

TECHNICAL SPECIFICATIONSColour Dark Grey

Swelling Volume 28 ml

Methylene blue absorption >390 mg/gm

Dispersion rate High

Plate Water Absorption (at the saturation level) 555%

pH 9-11

Moisture content 10%-12%

Permeability 10-10- 10-12 m/s

Bulk density(kg/m3) 1100-1400

CHEMICAL ANALYSISSilica as (SiO2) 35% - 37%

Alumina as (Al2O3) 18% - 20%

Iron as (Fe2O3 ) 4% - 11%

Calcium as (CaO) 1% - 1.5%

Copper as (CuO) 0.5% - 1%

Sodium as (Na2O) 0.5% - 1.5%

Carbon as (C) 8.3% - 9.3%

Remarks:- The Earthrite properties largely depend upon the quality of the water used. In extremely extra ordinary conditions and acidic water the results may vary.


Gypsum Graphite powder Conducting metal powders Bounding resinsNOTE: Backfill compound is enhanced, activated and chemically modified homogenous mixture based upon Bentonite made suitable for earthing purpose to increase the effectiveness of the earthing system.As per BIS : 3043 of Clause 8.5 it is also clearly stated that “if a greater degree of performance is envisaged, earth electrodes packed in material such as Bentonite are preferable.

3. HAZARDS IDENTIFICATION

Main hazards: No significant hazard. Other hazards: Combustible. Exposure Limits (Dust): 10 mg/m3 total dust, 4 mg/m3 repairable dust

4. FIRST AID MEASURES (SYMPTOMS)

Skin contact: There may be mild irritation at the site of contact. Eye contact: There may be irritation and redness. Ingestion: It is unlikely that this substance will be swallowed due to its physical properties. Inhalation: There may be irritation of the throat with a feeling of tightness in the chest.

5. FIRST AID MEASURES (ACTION)

Eye contact: Bathe the eye with running water for 5 minutes. Consult a doctor. Inhalation: Remove casualty from exposure ensuring one’s own safety whilst doing so

6. FIRE-FIGHTING MEASURES

Extinguishing media: Water spray, Alcohol or polymer foam, Dry chemical powder, Carbon dioxide Exposure hazards: In combustion emits toxic fumes of carbon dioxide / carbon monoxide. Protection of fire-fighters: Wear self-contained breathing apparatus.

7. ACCIDENTAL RELEASE MEASURES

Personal precautions: Refer to section 8 of SDS for personal protection details. Do not create dust. Environmental precautions: Do not discharge into drains or rivers. Clean-up procedures: Transfer to a suitable container. Refer to section 13 for suitable method of disposal.

8. DISPOSAL CONSIDERATIONS

Disposal operations: D1 Tipping above or underground (e.g. landfill, etc.). R4 Recycling/reclamation of other inorganic materials Disposal of packaging: Dispose of as normal industrial waste. Note : The user’s attention is drawn to the possible existence of regional or national regulations regarding disposal.

9. TRANSPORT INFORMATION

ADR / RID IMDG / IMO IATA / ICAO

10. REGULATORY INFORMATION


Hazard symbols: No significant hazard. Safety phrases: Do not breathe dust. In case of contact with eyes, rinse immediately with plenty of water and seek medical advice. Take off immediately all contaminated clothing. Wear suitable protective clothing. Note:The regulatory information given above only indicates the principal regulations specifically applicable to the product described in the safety data sheet. The user’s attention is drawn to the possible existence of additional provisions which complete these regulations. Refer to all applicable national, international and local regulations or provisions.

11. HANDLING AND STORAGE

Handling requirements: Ensure sufficient ventilation of the area. Avoid the formation or spread of dust in the air. Storage conditions: Store in cool, well ventilated area.

12. EXPOSURE CONTROLS / PERSONAL PROTECTION Occupational exposure limits TWA (8 hr exposure limit): 4mg.m3 Res Dust STEL (15 min exposure limit): 4mg.m3 Res Dust Engineering measures: Ensure there is sufficient ventilation of the area. Respiratory protection: Respiratory protective device with particle filter. Hand protection: Protective gloves. Eye protection: Safety glasses with side-shields. Skin protection: Protective clothing with elasticized cuffs and closed neck.

13. PHYSICAL AND CHEMICAL PROPERTIES State: Solid granular Colour: Dark grey Odour: Odourless Solubility in water: Insoluble Viscosity: Non-viscous Relative density: 890-990 kg/m3

14. STABILITY AND REACTIVITY

Stability: Stable under normal conditions. Conditions to avoid: Sources of ignition. Materials to avoid: Strong oxidizing agents. Haz. Decomp. Products: In combustion emits toxic fumes of carbon dioxide / carbon monoxide.

15. TOXICOLOGICAL INFORMATION

Chronic toxicity: Danger of cumulative effects through inhalation. Routes of exposure: Refer to section 4 of SDS for routes of exposure and corresponding symptoms.

16. ECOLOGICAL INFORMATION

Mobility: Non-volatile. Insoluble in water Heavier than water Persistence and degradability: No data available. Bio accumulative potential: No data available. Other adverse effects: Negligible eco toxicity.


Sr. No “DOKSUN” make Earthing Electrode Traditional Earthing

1 There is flat strip, one inside the pipe i.e., flat- in- pipe technology One G.I /C.I. pipe of particular diameter.

2 Earthing electrode is not in direct contact with the soil.

The earth electrode is in direct contact with the soil.

3 Corrosion Resistant. Due to a bed of BFC Around the electrode

Liable to fast corrosion, subsequent decay of earthing pipe/plate. Due to a bed of coal saltMixture around the electrode

4Least fluctuation of Ohmic value. It has been proved at various sites that Ohmic value of our earthing electrode reduces with age.

Fluctuation of Ohmic value is more, results in frequent maintenance of gadgets/machines and may endanger human life too.

5

Since our electrode is surrounded by highly con-ductive soil so the charge dissipation through the electrode is very high and the current densi-ty across the electrode is very low which results in very high fault current, which is sufficient to trip the fault relays.

Distribution of short circuit current is less in terms of charge dissipation therefore it generates high potential at the pit which result in low fault current in comparison to required tripping circuit of fault protection.

6 Copper coating/Galvanisation is adequate i.e., 250 microns/50 microns

Copper coating/galvanization is not ade-quate

7 Our electrode is non – corrosive, so there is not much variation in Ohmic value.

Salt, charcoal is used as back fill compound, as salt is highly corrosive electrolyte, it cor-rodes G.I / C.I electrodes. Results in high Ohmic value.

8 The back fill compound is not soluble in water & it becomes part of the soil around the electrode.

Back fill compound (salt) used will be washed away in rainy seasons and will be resulted as high Ohmic value.

9 It requires less space and time to install the earthing electrode.

It requires a large space and time to install the earthing electrode.

TECHNICAL COMPARISON


The initial cost of the conventional earthing system may seem to be low as compared to the “DOKSUN” make earthing system. But then, the conventional earthing system needs regular maintenance. As the conventional earthing systems do not follow any recent advancements, and due to simple installation, with passing time the electrode Plate or Pipe tends to decay. Then they are useless for effective earthing, because DOKSUN layer of corrosion on the electrodes also increases the resistivity DOKSUNly. This is the time when we have to install new earth pits, with new electrodes in them spend more money in replacing the old earth pits with new one and in maintaining of the earthing system.

Apart from spending more money it is the disruption of the smooth services due to faulty earthing system, which must be avoided in all condition because this results in loss of revenue and man power.

On the other hand however “DOKSUN” make earthing systems are a little costlier than the conventional earthing system but unlike the latter these earthing systems do not require any maintenance, and are corrosion resistant, least affected by weather conditions and have a very long life.

From the above it is clear that conventional earthing is cheaper in the first instance but if we take in to account the recurring expenses due to frequent maintenance & replacement of the earth pits, which is always going to be dearer with the time, then “DOKSUN” make Earthing Electrodes are the best available cost effective solution for a reliable and maintenance free earthing system and therefore money spent on “DOKSUN” make earthing system are not a recurring expenses rather a long term investment.

Key point summary:

• The relationship between value and no. of electrodes is NOT linear!

• Earth resistive value depends on the local soil conditions.

Cost Comparison of “DOKSUN” make Earthing Vs Conventional Earthing

BENEFITS APPLICATIONS• Peace of mind that readings WILL be achieved.

• Performance is outstandingly consistent what-ever the reason or season.

• Assured Safety

• Hassle-free solution

• Maintenance free

• Telecommunication Towers & Microwave Antennas

• Transmission & Distribution Systems• Substation & Power Generators• Computers & Data processing Centers• Manufacturing Facilities & Refineries• Generator Earths• Transformer Earths• Lightning protection in difficult conditions

Salient Features of Doksun make Earthing Electrode :

1. Unique anti-theft design.2. Dual conductivity path.3. Ensures guarantee of conductor inside.4. Unique, Sleek and robust design.5. A unique “feel” of safety.6. Can be connected either way.7. Series connection possible for greater depth.8. Use of ISI marked pipes. For better material.


Sr. No. Application E a r t h i n g Type Recommendation

1 Distribution Board Body Earthing 1 3 Mtr

2 Residential Flat Common Earth-ing 1 2 Mtr

3 Residential Flat up to six Flat Common Earth-ing 1 3 Mtr

4 TransformerBody Earthing 2 3 Mtr

Neutral Earthing 2 3 Mtr

5 GeneratorBody Earthing 2 3 Mtr


6 5 Computers Common Earth-ing 1 3 Mtr

7 UPS, Server, CNC Machines, Telecom-munication Equipments

Body Earthing 1 3 Mtr


8 Control panels Body Earthing 1 3 Mtr

9 Telecommunication / transmission tower Body Earthing 1 3 Mtr

10 Lightning arrestor Interconnected 2 3 Mtr

11 Hard Soil difficult to dig below 2 mtrs Interconnected 2 2 Mtr

12, MRI Machines, Radiation Machines or any other sensitive medical equip-ments

Body Earthing 1 3 Mtr


RECOMENDATIONS OF INDIAN STANDARD FOR EARTHING

• It is always better & safe to earth the Neutral even if earthing is provided for that by the power supplier

• The above information is given in general. The selection of earth electrode (Dia and Length) & quantity of earth pits for a particular application depends on various factors like soil resistivity of the area, equipments to be earthed, the amount of maximum fault current that can flow in to the electrical circuit at any given time, etc.

• It is suggested to consult a qualified electrical engineer / consultant before going for electrical earthing.


COMPLIANCE OF IS : 3043 INDIAN STANDARD for Earthing

IS 3043:1987 Descriptions from Indian standards Our Comments

8.6

At above about 20 percent moisture the resistivity is very little affected while below 20 percent the resistivity increase very abruptly with decrease in moisture content. A difference of little percent moisture will therefore, make a very marked difference in the effectiveness of the earth connection if the moisture content falls below 20 percent. The normal moisture content of soils ranges from 10 percent in dry seasons to 35 percent in wet seasons and an approximate average may be perhaps 16 to 18 percent.

Our back fill compound is highly hygroscopic in nature; it has high capacity to absorb moisture of its volume. Due to the water absorption the moisture percentage is adequately maintained during dry seasons.

8.8.1

Approximately 90 Percent of the resistance between a driven rod and earth lives within a radius of about two meters from the rod. This should be kept in mind when applying the agents for artificial treatment of soil.

Our back fill Compounds filled in vicinity of earthing electrode is highly conducting in nature and that helps to obtain lower earth resistance.

9.1.1

Where the resistance of a single plate is higher than the required value, two or more plates may be used in parallel and the total resistance is than inversely proportional to the number of employed, provided that each plate is installed outside the resistance area of any other. This normally requires a separation of about 10 m but for sizes of plate generally employed, a separation of 2 m is sufficient to ensure that the total resistance will not exceed the value obtained from the above formula by more than 20 percent.

For obtaining required value earth pit are connected in parallel considering the local soil condition and practical difficulties of installation.

9.2.1The use of Coke breeze as an infill is not recommended as it may result in rapid corrosion not only of the electrode itself but also of cable sheaths etc, to which it may be bonded.

Our system totally eliminate the use of charcoal and salts . we use specially developed BACK FILL COMPOUND for preventing corrosion

9.2.1

For conventional sizes, the resistance is approximately inversely proportional to the linear dimensions, not the surface area that is a 0.9 m x0.9 m plate would have a resistance approximately 25 percent higher than a 1.2 x 1.2 m plate. The current loading capacity of a 1.2 x 1.2 m plate is of the order of 1600 A for 2 s and 1300 A for 3 s.

T-19 Model is tested for 20 KA for 1 sec for short current and 50 KA peak in Central Power Research Institute Bangalore.

9.2.1

Pipes may be of cast iron of not less than 100mm diameter, 2.5 to 3 m long and 13 mm thick. Such Pipes Cannot be driven satisfactory and may, therefore, be more expensive to install than plates for the same effective area. Alternatively, mild steel water pipes of 38 to 50 mm diameter are employed.

We use 33mm to 77mm dia pipe of medium or heavy grade.


9.3

Care should be taken to select a material that is resistant to corrosion in the type of soil in which it will be used. Tests in a wide variety of soils have shown that copper, whether tinned or not, is entirely satisfactory (subject to the precautions given in this sub clause), the average loss in weight of specimens 150 mm x 25 mm x 3 mm buried for 12 years in no case exceed 0.2 percent per year. Corresponding average losses for unprotected ferrous specimens (For example, cast iron, wrought iron or mild steel) used in the tests were as high as 2.2 percent per year. Considerable and apparently permanent protection appears to be given to mild steel by galvanizing, the test showing galvanized mild steel to be little inferior to copper with an average loss not greater than 0.5 percent per year.

Due to use of heavy copper/galvanised plating as per UL standards and specially formulated BACK FILL COMPOUND the life of our system FLAT PATTI IN PIPE TECHNOLOGY exceed to more than 15 years in normal soil conditions.

8.3

A site should be chosen that is not naturally well drained. A water logged situation is not however, essential unless the soil is san or gravels as in general no advantage result from an increase in moisture content above about 20 percent. The abundance of water will not provide the soil with adequate conductivity. The value of high in the soil and in providing for solubility of ingredients moisture contents so is advantageous in increasing solubility of natural elements which are artificially introduced to improve soil conductivity.

The even mixture of our Back fill Compound maintains adequate moisture percentage and takes care of all these aspect and provide astonishingly very good conductivity.

8.1.1

Earth conductivity is however essentially electrolytic in nature and is affected, by the moisture content of the soil and by the chemical composition and concentration of salts dissolved in the contained water. Grain Size and distribution, and closeness of packing are also contributory factors since they control the manner I which the moisture is held in soil.

Our Black Fill Compound maintains adequate moisture percentage and takes care of all these aspect and astonishingly provides very good conductivity.

It is observed that rate of corrosion differs from place to place, from soil to soil due to its chemical properties. Though in most of the soil conditions, the hot dip galvanized earth electrodes are able to resist the corrosion but, due to non-uniform coating of the zinc, it is susceptible to corrosion at weaker points. The copper has an excellent corrosion resistant property in most of the soil condition, but is not widely used due to its high cost. Hence, need was felt to provide thick & uniform coating of the corrosion resistant materials on the external surface of the earth electrode to make it more suitable even in high corrosive soil considering the cost as well. Thus, “DOKSUN” took the initiative and few more earthing electrodes were made that can give thicker & uniform coating of various metals on the external surface of the earth electrode.

PROCESS ADVANTAGES:

1. Low temperature process, no bulk particle melting.

2. Retains composition/phases of initial particles.

3. Very little oxidation.

4. High hardness, cold worked microstructure.

5. Eliminates solidification stresses, enables thicker coatings.

6. Low defect coatings.

7. Lower heat input to work piece reduces cooling requirement.

8. No fuel gases or extreme electrical heating required.


1. The process of filling & coating is quality governed.2. High specific gravity CCM is injected inside the earth electrode through a specially designed SPM

under controlled pressure, giving a greater bonding strength between CCM particles.3. Uniform & smooth coating of the zinc4. Matt finish and aesthetic look5. Purity of the zinc used for coating is 99.99%6. Coating thickness 40-70 microns.7. Better anti – corrosion protection than hot-dip-galvanization8. Excellent soil interface due to electrode’s matt finish9. Coating is done under stringent quality control through a specially designed SPM and is equivalent

to zinc cladding10. Coating on the electrode is measured on each & every electrode unlike in hot-dip-galvanization

wherein random inspection is done.11. The process of coating is quality governed whereas hot-dip-galvanization is a quantity governed. 12. High current dissipation capacity due to increased surface area.

1. The process of filling & coating is quality governed.2. High specific gravity CCM is injected inside the earth electrode through a specially designed SPM

under controlled pressure, giving a greater bonding strength between CCM particles3. Uniform & smooth coating of the copper4. Matt finish and aesthetic look5. Purity of the electrolytic grade copper used for coating is 99.99%6. Coating thickness is 100-254 microns.7. Better anti – corrosion protection than zinc coating8. Excellent soil interface due to electrode’s glossy/matt finish9. Coating is done under stringent quality control through a specially designed SPM and is near to

copper cladding10. Coating on the electrode is measured on each & every electrode.11. The process of coating is quality governed. 12. High current dissipation capacity due to increased surface area.13. Coating is done on the mild steel pipes, and has much better mechanical strength (almost twice)

than the pure copper electrode for the same cross section area.14. Steel can absorb approx. 1.36 times as much heat as an equivalent volume of copper, and can

withstand higher temperature before melting (1510 °C compared to 1083 °C for copper)15. Suitable for corrosive atmosphere.

1. The process of filling & coating is QUALITY governed.2. High specific gravity CCM is injected inside the earth electrode through a specially designed SPM

under controlled pressure, giving a greater bonding strength between CCM particles3. Uniform & smooth coating of the Cr & Ni based alloy4. Matt finish and aesthetic look5. Coating thickness 80 – 100 microns, but can be increased on demand6. Better anti – corrosion protection.7. Excellent soil interface due to electrode’s matt finish8. Coating is done under stringent quality control through a specially designed SPM.9. Coating on the electrode is measured on each & every electrode.10. The process of coating is quality governed.

ZINC COATED “DOKSUN” MAKE EARTHING ELECTRODE:

COPPER COATED “DOKSUN” MAKE EARTHING ELECTRODE:

ALLOY COATED “DOKSUN” MAKE EARTHING ELECTRODE:


11. High current dissipation capacity due to increased surface area.12. More suitable for high corrosive & chemical infested environment.

The purpose of resistivity testing is to obtain a set of measurements which may be interpreted to yield an equivalent model for the electrical performance of the earth, as seen by the particular earthing system. However, the results may be incorrect or misleading if adequate investigation is not made prior to the test, or the test is not correctly undertaken. To overcome these problems, the following data gathering and testing guidelines are suggested:An initial research phase is required to provide adequate background, upon which to determine the testing program, and against which the results may be interpreted. Data related to nearby metallic structures, as well as the geological, geographical and meteorological nature of the area is very useful. For instance the geological data regarding strata types and thicknesses will give an indication of the water retention properties of the upper layers and also the variation in resistivity to be expected due to water content. By comparing recent rainfall data, against the seasonal average, maxima and minima for the area it may be ascertained whether the results are realistic or not. A number of guidelines associated with the preparation and implementation of a testing program are summarised as follows:

(a)Test Method

Factors such as maximum probe depths, lengths of cables required, efficiency of the measuring technique, cost (determined by the time and the size of the survey crew) and ease of interpretation of the data need to be considered, when selecting the test type. Three common test types are shown in Figure 1-2. The Schlumberger array is considered more accurate and economic than the Wenner or Driven Rod methods, provided a current source of sufficient power is used.In the Wenner method, all four electrodes are moved for each test with the spacing between each adjacent pair remaining the same. With the Schlumberger array the potential electrodes remain stationary while the current electrodes are moved for a series of measurements. In each method the depth penetration of the electrodes is less than 5% of the separation to ensure that the approximation of point sources, required by the simplified formulae, remains valid.

1.3.2 SOIL RESISTIVITY TESTING PROCEDURE GUIDELINES


The Wenner array is the least efficient from an operational perspective. It requires the longest cable layout, largest electrode spreads and for large spacings one person per electrode is necessary to complete the survey in a reasonable time. Also, because all four electrodes are moved after each reading the Wenner Array is most susceptible to lateral variation effects. However the Wenner array is the most efficient in terms of the ratio of received voltage per unit of transmitted current. Where unfavourable conditions such as very dry or frozen soil exist, considerable time may be spent trying to improve the contact resistance between the electrode and the soil.

Economy of manpower is gained with the Schlumberger array since the outer electrodes are moved four or five times for each move of the inner electrodes. The reduction in the number of electrode moves also reduces the effect of lateral variation on test results. Considerable time saving can be achieved by using the reciprocity theorem with the Schlumberger array when contact resistance is a problem. Since contact resistance normally affects the current electrodes more than the potential electrodes, the inner fixed pair may be used as the current electrodes, a configuration called the ‘Inverse Schlumberger Array’. Use of the inverse Schlumberger array increases personal safety when a large current is injected. Heavier current cables may be needed if the current is of large magnitude. The inverse Schlumberger reduces the heavier cable lengths and time spent moving electrodes. The minimum spacing accessible is in the order of 10 m (for a 0.5m inner spacing), thereby, necessitating the use of the Wenner configuration for smaller spacings. Lower voltage readings are obtained when using Schlumberger arrays. This may be a critical problem where the depth required to be tested is beyond the capability of the test equipment or the voltage readings are too small to be considered.

The driven rod method (or Three Pin or Fall-of-Potential Method) is normally suitable for use in circumstances such as transmission line structure earths, or areas of difficult terrain, because of: the shallow penetration that can be achieved in practical situations, the very localised measurement area, and the inaccuracies encountered in two layer soil conditions.

Wenner Array

Schlumberger Array

Driven Rod METHOD

(b)Selection of Test Method Type

In homogeneous isotropic earth the resistivity will be constant. However, if the earth is non homogeneous and the electrode spacing varied, a different value of resistivity (ρa) will be found for each measurement. This measured value of resistivity is known as the apparent resistivity. The apparent resistivity is a function of the array geometry, measured voltage (∆v), and injected current (I).

For the arrays described in the previous section the apparent resistivity is found from the field measurements using the following formulae.

APPARENT RESISTIVITY CALCULATION

Wenner Array

Where ρaw = apparent resistivity (Ω) a = probe spacing (m) ∆v = voltage measured (volts) I = injected current (Amps) R = measured resistance (Ω)


Schlumberger Array

Driven Rod

Where ρas = apparent resistivity (Ωm) l = distance from centre line to inner probes (m) L = distance from centre line to outer probes (m) R =measured resistance (Ω)

Where ρad = Apparent resistivity (Ωm) l = Length of driven rod in contact with earth (m) d = Driven rod diameter (m) R = Measured value of resistance (Ω)

Methods of Earthing. A) Single earth rod, B) Earth rod with Cu subterranean tape, C) Crows foot earth, D) Earth enhancing compounds placed around the earth rod, E) Insulated PVC sleeve can be used to ensure the lightning current is injected into the ground at a depth below the surrounding surface.

A B

ED

C


9 Resistivity values for several types of soil and water

9 Variations in Soil Resistivity with Moisture Content

9 Variation in resistivity with temperature for a mixture of sand and clay with a moisture content of about 15% by weight

Type of soil or water Typical Resistivity - Ωm Usual Limit - Ωm

Sea water 2 1– 10Clay 40 8 – 70

Ground well or spring water 50 10 – 150Clay and sand mixtures 100 4 – 300

Shale, Slates, Sandstones 120 10 – 100Loam and Mud 150 5 – 250

Lake and brook water 250 100 – 400Sand 2000 200 – 3000

Morazán Gravels 3000 40 – 10000Ridge Gravels 15000 3000 – 30000Solid Granite 25000 10000 – 50000

Ice 100000 10000 - 100000

Typical Resistivity in - Ωm

Silica based Sand Clay Mixed with Sand Moisture % by Weight

- 1 00 00 000 030 00 000 1500 2.5

50 000 430 52 100 185 10630 105 15290 63 20

- 42 30

Typical Resistivity in - Ωm Temperature - C

72 20

99 10

138 0 ( Water )

300 0 ( Ice )

790 -5

3300 -15

- 42


Why the price is so high?

A section of iron pipe driven into the ground with a wire conductor connected from the pipe to the electrical circuit will not always give a suitable low resistance path for electric current to protect personnel and equipment.

Our pipe technology has been developed after a decade of experience and effort to match the present day of electric / electronic environment. It gives very low earth resistance value to match the sensitive electronic equipment, unlike the conventional system. It gives the customer the value for money as our system is corrosion resistant, maintenance free and lasts over years. A cost comparison shows that over a period of 15 plus years, the maintenance cost of a conventional system will be three times more than the one time cost of “DOKSUN” make Electrode Earthing System. We have proven track record that ours is a more superior alternative to the conventional GI Pipe Earthing and Plate Earthing. Considering all these aspects, the cost is not at all high, in fact if it is compared to conventional methods of earthing.

Why ISI marking is not on the product?

Except for the mild steel pipes used in the manufacturing process, there is no BIS mark for any Chemical Maintenance Free Earthing electrodes. We follow the Code of Practice for Earthing as stipulated by INDIAN STANDARD in IS 3043 - 1987. However we use ISI marked MS pipes for making of earthing electrodes.

What material you are using inside the Earthing pipe and in backfill compound material ?

We fill crystalline conductive mixture inside the electrode, the ingredients of which are high conductive and corrosion resistant minerals. The backfill compound, which is hygroscopic by nature, consists of a mixture of minerals and soil friendly chemicals. Laboratory tests have shown that it can retain moisture 25 times it’s dry volume and enhance the area of conductivity around the electrode.

What shall be the earth resistance value?

It may please be noted that soil differs from place to place even in a small area. The type of soil determines the resistivity. Therefore, the earth resistance value of any given Earthing electrode will depend upon the soil resistivity of the area where the electrode is installed. The advantage of our electrode is that if the conventional Earthing shows a value of 3 ohms, ours will show a much lower value, and the value will come down over a period of three weeks, by which time the system sets itself.

FREQUENTLY ASKED QUESTIONS


How long will it take to install this earthing?

This new method of earthing is very simple and fast to install compared to conventional earthing. In fact 8-10 nos. of “DOKSUN” make earthing electrodes can be installed in a single day compared to one conventional old type earthing.

Sometimes we do not get lower values why?

See all the earthing electrodes are made up of finest and standard quality material available in the market, now what is the reason behind that some of the earth pits do not give lower values compared to many other earth pits.

There are many factors governing the value, like not proper mixing of BFC with earth and water, means mix water with BFC simultaneously then feed inside the augered hole, DO NOT POUR DRY POWDER AND THEN POUR WATER, THIS IS WRONG. Therefore mixing of BFC with water and earth is very important, next if the ground is of filled type the compound will not become solid on swelling as described elsewhere in the manual and the result will be poor conductivity means poor value, next if the ground is rocky, mouroum type, or sandy then there some other preventive measure have to be taken and if necessary more than one earth pit has to be installed and connected in parallel.

Therefore for getting of lower value entirely depends on methods of installation and ground conditions.

Why we install such heavy electrodes when earthing can be done by thinner wire also?

It is very true that earthing can be done by a thin wire also, but the question is why we use heavier earthing.

There are several parameters which can be considered. First the thinner wire tends to corrode in a given time. Second at the time of fault arised in a given situation the current called fault current will eat up the wire. In any circuit may be single phase or three phase the fault current generally tends to rise more than 10 to 15 times of operating or rated current. Heavier the fault current heavier the Earthing Electrode should be.

This is the fault current of any equipment which is being taken into consideration to use heavier electrode.


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DOKSUN POWER PRIVATE LIMITEDSURAT

Installation & Start-Up Manual on Safe and Maintenance Free Earthing

Complete solution for any type of Earthing System needs.

9 Heavy Copper Plated Pipe Earthing Electrode

9 Heavy Zinc Plated Pipe Earthing Electrode

9 Stainless Steel Pipe Earthing Electrodes for special needs

9 Pipe Electrodes for general Coal + Salt mixture Earthing

9 Plate Electrodes for general type Earthing

9 Heavy Zinc Plated strips (patti) for Earthing connection

9 Back Fill Compound (ground enhancement material)

9 Coal + Salt mixture for general Earthing mixed in required proportion

Complete solution for all types of lightning system needs.

9 ESE Type Lightning Arrestors

9 Conventional type Lightning Arrestor SS 304 make copper bonded

9 Complete Accessories for installation of Lightning Arrestors

9 Lightning Strike Counters

Other Products Catalogue:

• Doskun Lightning Protection.• Doksun Pipe Earth Electrodes.• Doksun Solid Earth Electrodes.

Doksun Power Private Limited1st floor , Plot No 96 , Revenue Survey No 189 ,Ghael Compound,B/H Nissan Showroom,Udhana Main Road,Surat - 394210,Gujarat(India)

[email protected]@[email protected]

All rules and regulations and law, subject to SURAT jurisdiction only. 2012-2013 DOKSUN POWER PRIVATE LIMITED All rights reserved.

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Documents

Maintenance Free Earthing System - Doksun Power To provide an alternative path for induced current and minimize the electrical noise in cables. The earthing system consists of, conductive