Introduction

The most underground structures have been electrically bonded in common to reduce hazardous voltages associated with lightning and man-made fault currents or induced currents in the earth.
A common grounding system provides an economical and lower resistance to remote earth than does an individual earthing connection. This tends to ensure a low resistance return path for power system earth return currents and fault currents.
An additional benefit is minimizing earth potential gradients around individual earthing electrodes or elements.
It also tends to reduce step and touch voltages at the surface of the earth.

Characteristics of a Good Grounding System

	Good electrical conductivity that cause: Low resistance and electrical impedance. Conductors of sufficient dimensions capable of withstanding high fault currents with no evidence of fusing or mechanical deterioration in the event of a foreseeable fault. The lower earth resistance ensures that energy is dissipated into the ground in the safest possible way. The 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.
	Good corrosion resistance: Electrically interconnecting many dissimilar metals in the soil environment can lead to significantly increased corrosion rates on some of the underground structures. In addition to its inherent high conductivity copper is usually cathodic with respect to other metals in association with grounding sites.
	Mechanically robust, reliable and ability to perform for at least 40 years working life-time for a facility.

Selection of Conductors and Related Corrosion Problems
When materials such as black iron (BI) cast iron (CI), and ductile iron (DI) are inter connected, they are very close together in the
electromotive series of metals and therefore, each would suffer very little additional corrosion by connecting to the other metal.

Copper
is electropositive with respect to all ferrous construction materials.

Aluminium
has been used for ground grid less frequently.

Steel
has been used for ground-grid conductors in many European countries mainly for the benefit of eliminating most of the adverse effects
of copper already mentioned. Application of galvanized or stainless steel in combination with cathodic protection is typical.

Earth Electrodes & Fittings

1-Copper Bonds Earth Rods & Fittings
Copper bond earth rods are the ideal driven earth electrodes, as they offer the installer an economical and efficient earth rod grounding system. pure electrolyte copper is uniformly molecularly bonded into a high tensile steel core to a minimum thickness of 0.254 mm, thus ensuring excellent corrosion resistance and eliminating electrolytic action.
Coupling threads are formed by a rolling process to ensure thread strength and to maintain the integrity of the molecularly bonded copper.

2-Solid Copper Earth Rods & Fittings
These rods are designed for use where extremely high corrosion resistance and exceptionally long life is required. Manufactured from hard drawn copper with purity and mechanical properties to BS 2874 , hard drawn grade C101,C102

3-Stainless Steel Rods & Fittings
These rods are designed for use where problems may be caused by galvanic corrosion , due to dissimilar metals being buried in close proximity. In this situation a copper rod may react adversely with the buried metal, thus allowing corrosion to take place. The solution is to use stainless steel rods or austenitic stainless steel to BS970 Grade 316S12.

4-Earth Plates
In special position for reducing resistance to earth of an earth electrode, these earth plates can be used.

	Solid Copper Earth Plates
	Lattice Copper Earth Plates
	Grounding Equipotential Mats

Earth Rod Clamps

	Rod to Cable Clamp
	Rod to Tape Clamp
	Rod to Tape or Cable Clamp
	"U"  Bolt Rod Clamp

Structure Clamps

	Grounding Wire Clamp
	Cable-Support Clamp
	Grounding Wire Clamp (4 Way)

Earth Joints & Acc.

	Bimetallic Washer
	Connector Clamp
	Flexible Copper Earth Bond
	C Clamp
	Cable Lug
	Earth Bars & Disconnecting Links

Earth Inspection Housings
Designed to protect & make available for inspection & testing the Earth Rods & Earthing Connections.

	Galvanized Lid Inspection Pit
	concrete inspection pit

Backfill for Earthing Bed
One method of reducing the ground bed resistance is to surround the rod electrodes with low resistively soil, This work has several advantages:

	Reduce rod to soil resistance
	Provide a uniform environment so that the rod output is predictable and constant
	The backfill has not organic acids and anaerobic bacteria, consequently reduces rate of corrosion in the neighborhood of rods.

Petunia produces PETINFILL^TM in appropriate case and 25 kg polyethylene bags. PETINFILL^TM  is coal coke breeze of low resistivity and low ash content.

The coke breeze may be treated by the addition of 10% (by weight) of commercial grade slaked lime.

Earth Rod Drivers
includes driver body with soft rubber grip & driving element appropriate for inserting rods to ground level are supplied by petunia.

Temporary Earthing Devices (TED)

Temporary EARTHING Device is hand-held equipment that is brought and connected to the connecting points of parts of electrical installation for earthling and it permit conductors to be earthed as well as short-circuited.
Petunia is manufacturer of an acceptable range of temporary earthing devices for 20 KV to 400 KV voltage and maximum 33.5 KA, 0.5 Sec short circuit current in two types.

a) Single pole devices
b) Three pole devices

Each devices consist of following components:

1) HIGH VOLTAGE CONDUCTOR SCREW CLAMP

2) EARTHING CABLE

3) PENETRATING EARTHING CLAMP

4) EARTHING POLE

Conductors

All of conductors are manufactured in accordance with the relevant standards. The following conductors represent our standard range and for non standards place contact us.

	BARE STANDARD COPPER CONDUCTOR
	YELLOW/GREEN PVC COVERED STANDARD COPPER CONDUCTORS
	FLAT COPPER & ALUMINIUM TAPE
	P.V.C COVERED COPPER & ALUMINIUM TAPE
	HARD DRAWN COPPER BAR
	TINNED COPPER TAPE
	FLEXIBLE COPPER BRAID
	LEAD COVERED COPPER TAPE