1. Practical Earth Testing Techniques and Measurement Instruments

2. Practical Earth Testing
Content
Principles
Test Methods
Practical Measurement
Summary
First we look at some of the basic concepts behind grounding then the test methods used for ground testing.
Then we‘ll look at the practical side of measurement with explanation of the results obtained and what to look out for to ensure the results you get are correct. Finally we‘ll summarise.

3. Earth / Ground Basics What is ground?
A conducting connection, whether intentional or accidental, between an electrical circuit or equipment and the earth, or to some conducting body that serves in place of earth*
A statement from the National Fire Protection Association defines ground as any connection to earth. An important part of the definition is the differentiation between intentional and accidental connection. There may be an intended path to earth that fails and as there is an accidental circuit exists all seems OK until the accidental path is disturbed and then systems can fail intermitantly. Ground testing ensures that intentional circuits are functioning within the required specification.
Ground is a connection to Earth made either intentionally or accidentally
*NFPA (National Fire Protection Association)

4. Earth / Ground Basics Why ground? To protect people and equipment
By dissipating stray energy from:
Electrical faults (fuses, breakers etc.)
Lightning strikes
Radio Frequency
Static discharges
The main reason for grounding is to ensure that people and equipment are protected. Grounding assists in dissipation of electrical energy present due to unforeseen conditions such electrical faults. Grounding is important for the correct operation of circuit protection devices such as fuses and circuit breakers. These devices are used to protect users and electrical equipment, for example in preventing electrical fires.

5. Real Examples Why test? – Catch the problem before it happens!
Estimate: at least 15% of power quality problems are related to grounding
Lightning strikes on equipment with poorly maintained protection systems destroy millions of dollars of equipment and lost production every year
Using ground testing in a PDM protocol will help prevent possible dangerous situations and loss of downtime (= money)
It’s estimated that at least 15% of power quality problems are related to grounding, ensuring good grounding by testing can ensure these problems don’t escalate
Lightning strikes on equipment with poorly maintained protection systems destroy millions of dollars of equipment and lost production every year
Using ground testing in a PDM protocol will help prevent possible dangerous situations and loss of downtime (= money)
Ground testing can be used as part of preventative maintenance strategy.
Ensuring good ground can locate potential problems before they occur.
Figure of 15% is given in EPRI PEAC report from a few years ago.
There‘s lots of examples of situations where lightning strikes have caused damaged to poorly maintained lightning protection systems. See
And

6. Earth / Ground Basics How do you connect to earth? Cable or tape
Ground systems can go from the very simple such as a single metal stake, (typically made of copper for minimum resistance) to the complex such as buried mesh connected to the site foundations. The overall effectiveness of the ground system depends on the physical shape and size of the conducting material and the type of earth the system is buried in.
Stake or rod
Earth material

7. Earth / Ground Basics Spheres of influence
When conducting objects are buried in the earth they are described as having a sphere of influence when conducting current to earth. The sphere of influence will vary depending on the shape and size of the conducting object. If two objects are burried close to each other their spheres of influence will overlap and not be as effective as they would be if there were a greater distance apart. When ground testing it‘s important to ensure the test stakes are not effected by the sphere of influence of the ground system under test.

8. Attention! Potential gradients!
Earth / Ground Basics
Attention! Potential gradients!
Umeasure
Potential gradients around the earth electrode can reduce the accuracy of measurements!
The probe must always be placed outside this area! Typical distance: >20m
Distance a
Ground Potential
Neutral ground, reference
Umeasure 8 8

9. Earth / Ground Basics Types of Grounding Systems Ground rod
Many different types available
Choice depends on local conditions and required function
Simplest form is a single stake
Mostly used for:
Lightning protection
Stand alone structures
Back-up for utility ground
The next slides are to bring the point out that there‘s a huge variety of ways of creating a ground system.
For simplicity in the presentation we refer to ‘ground electrode‘ or ‘grounding system‘ to describe these different methods of grounding.
It should be noted that there are many different types of grounding systems available.
The type installed will depend on the local conditions and the required function of the grounding system
The simplest form of grounding element is the ground stake, this can take many forms with a variety of lengths from a few feet to many feet long made of materials such as brass, galvanised or stainless steel, the size and material as required locally
The simple ground rod can be used for lightning protection on stand-alone structures such as pole mounted transformers or radio towers, it can also be used as a back up to a utility ground.
Ground rod

10. Earth / Ground Basics Types of Grounding Systems Ground rod group
typically for lightning protection on larger structures or protection around potential hotspots such as substations.
A group of connected rods will have a more complicated interaction, typically configurations like this are present around substation sites and sensitive buildings.
A slightly more complicated version of the rod system is the ground rod group, this is typically for lightning protection on larger structures or protection around potential hotspots such as substations.
Ground rod group

11. Earth / Ground Basics Types of Grounding Systems Ground plate
For areas where there is rock (or other poor conducting material) fairly close to the surface ground plates are preferred as they are more effective
Ground plates are used widely in telecoms applciations. They are particularly good where the deeper ground has high resistivity.
For areas where there is rock (or other poor conducting material) fairly close to the surface ground plates are preferred as they are more effective
Ground plate

12. Earth / Ground Basics Types of Grounding Systems Ground mesh
A ground mesh consists of network of bars connected together, this system is often used at larger sites such as electrical substations.
Ground meshes can be part of the foundations of structure. At substations and generating site the metal parts of the foundations will all be bonded together and form part of the overall grounding systems. At substation site an area of ground could be reserved at the start of the life of the substation with a ground mesh under the whole of the site. As the site grows over a period of years new equipment can easily be installed and grounded by the mesh. This ensures that the whole of the site remains at the same potential should a fault occur.
Ground mesh

13. Earth / Ground Basics Types of Grounding Systems
For the purposes of this presentation the grounding system will referred to as ‘ground electrode’.
Create a common phrase of ‘ground electrode‘ to refer to grounding system from here on.

14. Ground Testing Methods
What are the available techniques?
Resistivity
Fall of Potential – Three and Four Pole Testing
Selective Testing
Stakeless Testing
Two pole method
The resistivity test is normally used prior to installing a grounding system, it‘s a test of how effective the earth at the intended ground system site will be.
There are a number of techniques for ground testing, the most common method is the Fall of Potential test.
The selective test is based on the fall of potential test but has the advantage of minimising disrruption during testing.
The stakeless test enables testing to be carried out in situations where access to the earth is difficult or impossible.
The two-pole method is a last ditch method when none of the other methods can be used.

15. Ground Testing Methods (1)
Resistivity Measurement
The purpose of resistivity measurements is to quantify the effectiveness of the earth where a grounding system will be installed.
Differing earth materials will affect the effectiveness of the grounding system.
The capability of different earth materials to conduct current can be quantified by the value E (resistivity in W.m).
Resistivity measurements should be made prior to installing a grounding system, the values measured will have an effect on the design of the grounding system.
Resistivity should be measured prior to ground system design as it checks the effectiveness of the local geology.

16. Ground Testing Methods (1)
Resistivity values for different earth materials
Examples of resistivity values from moist soil to rock.
Some examples are shown of how effective rods and strips would be depending on the state of the earth locally.

17. Ground Testing Methods (1)
Resistivity Measurement ( Wenner method)
Resistivity measurements are performed by using a four wire method.
Used to determine which KIND of earthing should be used, so BEFORE placing earth stakes
Four stakes are used during resistivity testing. The distance between the stakes should be measured. This distance depends on the total area and the local resistivity. Typical distances are 6 and 12 feet, but if large areas have to be surveyed the distances may need to be larger, in that case it would be important to have oversized stakes, maybe even 3 to 6 feet long. Those types of surveys are more specialised. The outer two spikes inject test current and the inner two spikes measure voltage, a value of resistance is then derived

18. Ground Testing Methods (1)
Resistivity Measurement
From the indicated resistance value RE, the soil resistivity is calculated according to the equation :
E = 2  . a . RE
E mean value of soil resistivity (W.m)
RE measured resistance (W)
a probe distance (m)
Resistivity has to be calculated using the measured value Re.
It becomes evident at this point that measuring the distances between the test spikes is important as it has an effect on the result achieved. Note the measurements and values refer to metres. All the tables of resistivity I’ve been able to find are in ohm metres although it’s possible to have ohm inches or ohm feet etc.

19. Ground Testing Methods (1)
Resistivity Measurement
Curve 1: As E decreases only deeper down, a deep earth electrode is advisable
Curve 2: As E decreases only down to point A, an increase in the depth deeper than A does not improve the values.
Curve 3: With increasing depth E is not decreasing: a strip conductor electrode is
advisable.
The is shows the different type of curves that can be produced. The characteristic graphs give an indication about the the ground.
Curve 1 shows a situation where the surface material may be dry but lower levels have material with lower resistivity (that’s a good thing for creating a ground system with a low value of resistance). In this case deep rods are suggested.
Curve 2 shows a variance of low resistivity at the level A. Deeper rods and rods close to the surface won’t give lower resistance.
Curve 3 shows a situation where the best material is close to the surface. Driving deep rods doesn’t offer any advantage. The better solution is to have a mesh or plate close to the surface.

20. Ground Testing Methods (2)
Fall of Potential - Testing
The Fall of Potential method is the most commonly used method of testing.
Three or four pole method, this refers to the number of connections made to the ground tester.
The forth pole of the connection is made if the wire to connect to the system under test is particularly long
> 4 meters. The additional wire cancels out an error due to the extended length of wire used.
The Fall of Potential method of ground testing is the most commonly used method of testing.
The method can be used in what is described as either a three or four pole method, this refers to the number of connections made to the ground tester.
With this method, two test spikes are used and either one or two connections made to the ground under test.
The forth pole of the connection is made if the wire to connect to the system under test is particularly long
>12 feet.
The additional wire cancels out an error due to the extended length of wire used.

21. Earth Testing Methods (1)
Ground Testing Methods (2)
Earth Testing Methods (1)
Fall of Potential – 3 / 4 Pole Testing
The E terminal of the instrument is connected to the electrode under test
Firstly the electrode under test is connected to the instrument E terminal.

22. Earth Testing Methods (1)
Ground Testing Methods (2)
Earth Testing Methods (1)
Fall of Potential – 3 / 4 Pole Testing
If the length of this wire is greater than 4 meter it is recommended that an extra wire is connected between the electrode under test and the ES terminal to eliminate any error introduced due to the length of the lead, this is then known as the 4 pole test
In some cases the wire connecting the instrument to the electrode under test must be extended beyond the normal test lead length. If the test lead needs to be extended more than say, 12 feet then an additional wire should be introduced connecting the electrode under test to the ES terminal of the instrument. This eliminates any voltage drop along the test lead, when this second connection is in place the test becomes a four pole test – because there will be four wires in place during the test.

23. Earth Testing Methods (1)
Ground Testing Methods (2)
Earth Testing Methods (1)
Fall of Potential – 3 / 4 Pole Testing
The test spike C2 is placed in the ground some distance from electrode under test (typically 50 meter)
After connecting the eletrode under test a temporary current spike is introduced, this is pushed into the ground about 165 feet away from the electrode under test, this is the length of the cable supplied with the instrument.

24. Earth Testing Methods (1)
Ground Testing Methods (2)
Earth Testing Methods (1)
Fall of Potential – 3 / 4 Pole Testing
The voltage spike P2 is placed in the ground some distance from electrode under test (typically 80 feet) . Once the stakes are in place the test can proceed.
During the test the instrument drives a current through the test spike, through the surrounding earth and returns through the electrode under test, the potential caused by this current is measured using the P2 spike.
From the current and voltage measurements made it is possible to calculate a value of ground resistance.
Next a potential spike P2 is introduced, this will measure voltage during the test sequence. This spike is placed about half way between the current spike and the electrode under test, around 80 feet. With this spike in place the test can be carried out, during the test sequence the instrument drives a current through the C2 spike, through the earth and returns through the electrode under test. During this process the potential spike P2 measures the voltage cause by the current flow. From the current and voltage it is possible to derive a value of ground resistance.

25. Earth Testing Methods (1)
Ground Testing Methods (2)
Earth Testing Methods (1)
Fall of Potential – 3 / 4 Pole Testing
A number of readings should be taken with the the P2 spike at different distances, say from 20 to 35 meters at 3 meter intervals.
To ensure that the measured value is correct the P2 spike should be placed in a number of different positions and test carried noting the readings at the different distances. Typically readings should be taken about 10 feet apart.

26. Earth Testing Methods (1)
Ground Testing Methods (2)
Earth Testing Methods (1)
Fall of Potential – 3 / 4 Pole Testing
The distance of the P2 spike is varied to ensure that it is positioned outside of the sphere influence of the electrode under test.
When the P2 spike is close to the electrode under test the measured value appears to be lower and as it becomes influenced by the C2 spike the measured value rises.
The optimal point of measurement is outside of the influence of the electrode and the C2 spike.
Taking a series of measurements and plotting these against distance produces the curve shown.
The distance is varied to ensure that the measurements are correct and not in the sphere of influence of the electrode under test – refer back to slide 6.

27. Earth Testing Methods (1)
Ground Testing Methods (2)
Earth Testing Methods (1)
Fall of Potential – Creating the ‘S’ Curve
The optimum value is that indicated on the flat part of the curve
If the series of readings is plotted on a graph of ground resistance against distance, this produces a graph as shown. The flat part of the graph produces what is considered at the optimum value of resistance.

28. Earth Testing Methods (1)
Ground Testing Methods (2)
Earth Testing Methods (1)
The 62% Rule
The 62% rule is a guide to how far away the P2 and C2 stakes should be placed from the electrode under test.
The distances are nominally based on the depth of the electrode.
As a guide to how far the temporary stakes are place the 62% rule can be used. The distances are normally dependant on the depth of the electrode under test. This is applicable for testing ground electrodes.

29. Earth Testing Methods (1)
Ground Testing Methods (2)
Earth Testing Methods (1)
Distances for Electrode Arrays
The 62% rule is a guide to how far away the P2 and C2 stakes should be placed from the electrode under test.
The distances are nominally based on the depth of the electrode.
As a guide to how far the temporary stakes are place the 62% rule can be used. The distances are normally dependant on the overall size of the array under test. This is applicable for testing ground electrode arrays.

30. Selective Measurement Method
Ground Testing Methods (3)
Selective Measurement Method
A current clamp is used to isolate the test current injected in to the electrodes under test.
The selective method is based on the fall of potential test
But: without the need to disconnect the ground electrode under test.
Test Current
Test Current
Test Current
Test Current
The selective method is based on the Fall of Potential test, however it‘s not necessary to disconnect the ground electrode under test !
A current clamp is used to isolate the test current injected into the electrodes under test, the current will flow to earth by any path.
By isolating the current, with use of the current clamp, the ground resistance of individual elements can be measured without disconnecting.
If the total resistance of the ground system should be measured, then each earth electrode resistance must be measured by placing the clamp around each individual earth electrode.
Then the total resistance of the ground system can be determined by calculation.

31. Selective Measurement Method
Ground Testing Methods (3)
Selective Measurement Method
This application example shows the benefit of the selective test in a typical installation
Firstly the ground spikes are positioned according to the requirements of the system under test.
When using the selective method a group of measurements can be made simultaneously. In this case the fall of potential setup is made and the current clamp is moved around the ground bar where the different elements of the grounding system are connected.

32. Selective Measurement Method
Ground Testing Methods (3)
Selective Measurement Method
Then individual elements of the system can be measured by placing the currentclamp around the different connections to ground without the need of any disconnection.
This makes it possible to measure a variety of ground elements which might not be that nearby.

33. Selective Measurement Method - Advantages
Ground Testing Methods (3)
Selective Measurement Method - Advantages
Ground electrodes can be tested without powering down the system they are protecting – saving time and money
Testing can be carried out without disconnecting – saves time, money and improves safety
Multiple electrodes can be tested quickly simply by moving the current clamp to individual electrodes
The advantages of the selective method, the safety aspect is very important. Some utilities has started making this method the only safe method at substation sites due to the dangers of making disconnections. Measuring a number of different elements from the same point makes testing much quicker.

34. Ground Testing Methods (4)
The stakeless method eliminates the need for temporary ground stakes. This is useful in a wide range of situations. Examples include:
Inside buildings
Airports
Urban locations
Chemical and industrial plants
The stakeless method is not available on all ground testers. However, it comes standard on the Fluke 1623 and 1625 earth ground testers.
The temporary ground stakes are replaced by two current clamps. The first clamp generates a voltage on the ground condutor, the second clamp measures the current flowing due to the generated voltage.

35. Ground Testing Methods (4)
The Fluke 1623 and 1625 testers are able to measure earth ground loop resistances for multi grounded systems using only current clamps.
With this test method, two clamps are placed around the earth ground rod or connecting cable and each connected to the tester. Earth ground stakes aren‘t used at all.
The generating clamps EI162AC are connected to the instrument in two ways for the 1623 and 1625.
The 1623 simply uses short red and black leads supplied with the instrument but a black jumper lead connects the H & S terminals on the instrument.
The connection of the 1625 is more or less the same but uses a three wire to two wire adapter.
The sensing clamp EI162X uses the same lead in both cases. As one clamp is generating a field and the other is measuring a field they should be kept apart if possible by the EI162X does have good shielding.

36. Ground Testing Methods (4)
The clamps are placed around the ground conductor
This points out that the stakeless method does need a lot of parallel paths to be present to ensure good results. Groups of pole grounds is good example of a successful application.

37. Stakeless Measurement Equivalent Circuit
Ground Testing Methods (4)
Stakeless Measurement Equivalent Circuit
The equivalent circuit of the stakeless measurement shows the many parallel element. If we are looking for the value Rx the combined value of R1 to Rn are very low in comparison as they are parallel elements. The voltage source represents the EI162AC clamp and is inducing a voltage, the ammeter is the other EI162X clamp measuring current. The instrument effectively has a voltage measurement and current measurement and can derive a value of resistance.

38. Ground Testing Methods (4)
If there is only one path to ground, like at some residential applications, the stakeless method will not provide an acceptable value and the Fall of Potential test method must be used.
An abnormally high reading or an open circuit indication on the instrument points to a poor connection between two or more of the aforementioned critical components.
An abnormally low reading could indicate the instrument is measuring a loop of bonding conductors.

39. Ground Testing Methods (5)
Two Pole Method
Used where other methods are not available.
Uses nearby metal structures as a temporary spike.
Metal water pipes are typically used
The two pole method is an old method that was used before the stakeless method became available.
It can provide variable results. It uses only one other resistance so won’t be as accurate as the stakeless method where many parallel paths are available. Imagine in the case the resistance of the electrode under test is 10 ohms and the resistance of the water pipe or metallic object is 10 ohms, the result measurement will be 20ohms – 100% error.

40. Ground Testing Methods (5)
Two Pole Method
Drawbacks:
The resistance of the metal pipe should be significantly less than the electrode under test.
Metal pipes are being replaced with plastic.
Some metal pipes use plastic couplings.
Other problems with this methods include the introduction of plastic joints or worse plastic pipes.

41. Selecting a test method
Summary of Ground Electrode Test Methods
Advantages
Drawbacks
Fall-of-Potential
Widely accepted
When you see the characteristic curve you know you’ve got a good measurement.
You have to disconnect ground
The stakes may not be to drive
There may not be space around the ground electrode to drive the stakes
Selective Method
Don’t have to disconnect electrode
The stakes may not be easy to drive
There may not be space around the ground
Stakeless Method
Convenience
Assumes a low-impedance parallel path
Possible to get very low readings by mistakenly measuring on a hard-wired loop
Two-pole Method
Impossible to judge the integrity of the “auxiliary electrode.”
Can’t be sure you are outside the area of influence
Summary of the available methods with advantages and possible problems.

42. Ground Testing Applications
When and why ground test?
Prior to designing an grounding system: the ground material should be evaluated by resistivity measurement before designing a ground system
Initial test on new ground systems: the real effectiveness of new ground systems should be measured before connection – fall of potential test
Periodic tests on ground systems: ground systems should be checked periodically to ensure they are not affected by changes in the ground or corrosion – selective or stakeless test
Which techniques to use in which situations.
Before using a grounding system it should be checked that it performas as expected.
Periodic test ensure the system is still working properly.
Pointing out that ground testing is an important part of predicitive and preventive maintenace schedules.

43. Ground Testing Applications
When and why ground test?
Testing prior to addition of major loads: prior to installation of sensitive equipment such as servers, CT scanners, control systems, etc. – fall of potential, selective or stakeless
Safety tests on major equipment and plant e.g. ground tests on machines, elevators, conveyor belts, transformers, substations, boards, motors – stakeless and selective testing especially useful
Prior to installing major equipment many installers carry out checks to ensure that the electrical system can take the load and that there isn‘t any power quality problems present – significant harmonics or leakage current. The same logic applies to the grounding of the system these sensitive loads can have problems due to bad grounding, testing before connection can save time and money.
Electrical safety on large equipment is closely allied to good grounding. The selective and stakeless methods are good because it means nothing has to be disconnected which is in itself a potential safety issue.

44. Ground Testing Applications
When and why ground test?
All other tests for relevant ground connections e.g. lightning protection, pipelines, tanks, gas stations, antenna systems, telecommunication lines, “faraday” cages – fall of potential, selective or stakeless
PQ troubleshooting, quantify the effectiveness of grounding by measurement – fall of potential, selective or stakeless
All types of electrical systems have grounding present. Lightning protection is a significant application for these tester. Regions east of the Rockies tend to have the higher rates of lighning strikes through the year. Travelling south and west where the problems in states around the Gulf of Mexico have very high levels of lightning. The Pacific North West having the lowest levels in the US.

45. Choosing the right instrument
Introducing the Fluke 1623 and 1625 Ground Testers

46. Fluke 1623 Feature Summary Customer Application
Conventional 3 - and 4 - pole earth/ground testing
Selective method
Stakeless method
Two pole AC resistance measurement
One button measurement – press once to measure with simple GO/NOGO indicators
Large easy to read display
Rugged housing rated to IP56
2-Year Warranty
Customer
Electrical Consultants, Industrial
Application
Verification of earth resistance of electrical & communication systems.
Tell something about the AC signal used – 128Hz squarewave

47. Fluke 1625 - the expert instrument
Feature summary
3- and 4-pole measurement of earth resistance
Selective and Stakeless method
Monitoring and display of probe and auxiliary earth resistance
Automatic display of external voltage and frequency
Selection of optimal measuring frequency (AFC)
measurements down to deep ground layers possible (high testsignal power: >250mA, 48V)
Earth impedance R* of high tension towers - for calculation of genuine short circuit current
3- and 4-pole measurement of earth resistance
Selective and Stakeless method
Monitoring and display of probe and auxiliary earth resistance - optimal noise suppression due to SMR and automatic frequency control AFC ( Hz) - specific earth resistance as per Wenner - measurements down to deep ground layers possible (high test signal power: >250mA, 48V)
Automatic display of external voltage and frequency - protection against faulty handling and damage - selection of optimal measuring frequency (AFC)
3- and 4-pole, selective earth measurements with clamp: - measurement of single earth electrodes without any influence from parallel earth connections without disconnecting
Stakeless earth measurements with two clamps - for earth loop measurements without setting of earth stakes and without disconnection of earth conductors
Earth impedance R* of high tension towers - for calculation of genuine short circuit current 17 17

48. Fluke 1625 - the expert instrument
Additional features of Fluke 1625
2 pole AC resistance measurement - Resolution: Ohm - Measuring signal: 20V / 250mA
2 pole, 4 pole DC resistance measurement - Range: 3 kOhm, resolution: Ohm - automatic polarity reversal, adaptation of test period - short circuit current >200mA as per IEC/EN , UM >4V
User defined limit settings - adjustable limits for any individual applications
Interface and software available as option - data transfer to PC or printer - comfortable data evaluation with WinGEO software
Additional features of Fluke 1625
2 pole AC resistance measurement - Range: 200 kOhm, resolution: Ohm - Measuring signal: 20V / 250mA - Compensation of test leads - Measurement if stakeless measurement is not applicable
2 pole, 4 pole DC resistance measurement - Range: 3 kOhm, resolution: Ohm - automatic polarity reversal, adaptation of test period - short circuit current >200mA as per IEC/EN , UM >4V - Compensation of test lead resistances
User defined limit settings - adjustable limits for any individual applications
User guidance by terminal monitoring - Faulty connections are impossible - optimal user guidance by display symbols
Interface and software available as option - data transfer to PC or printer - comfortable data evaluation with WinGEO software 17 17

49. Unique: R* - Earth impedance
Fluke the expert instrument
Unique: R* - Earth impedance
Measurement of complex earth-impedance at 55Hz which determines the real short circuit current 17 17

50. Fluke 1625 - the expert instrument
Unique: R* - Earth impedance
Measurement of complex earth-impedance at 55Hz which determines the real short circuit current

51. Chosing the right instrument
Introducing the Fluke 1623 and 1625 Ground Testers
Features for each instrument.

52. Clamp-On Earth Loop Tester GEO 30
Feature Summary
Ground loop resistance clamp measurement
Low level measurement of ground leakage current
Wide AC current measurement range up to 30A with one instrument
Rapid evaluation of continuity loop resistance by audible HI/LO alarm
Easy to use, convenient, Display-HOLD function
Time saving memory function for saving measured values and automatic recording
Automatic self calibration ensures correct measurement every time
Customer
Residential, Commercial, Industrial Electricians
Application
Earth loop resistance testing for houses, commercial and industrial buildings

53. LEM GEO 30 - Ground Tester / Current Meter
Clamp-On Earth Loop Tester GEO 30
LEM GEO 30 - Ground Tester / Current Meter
Stakeless Ground Resistance Measurement　　　　　
Current amplifier
Voltage generator I Rx Rn U
The voltage U developed by the clamp is injected into the circuit. This causes a current I which flows in this measuring circuit. The second clamp measures this current I and the earth clamp displays the ground loop resistance Rx+Rn.

54. Clamp-On Earth Loop Tester GEO 30
High quality, rugged carrying case
High Quality measuring instrument
Calibration loop for instrument check
Includes five language operators manual E/D/F/ES/IT

55. Fluke 1653
Target Customer – Professional Electrician / Testing Specialist
Top Line Model with Unmatched performance
Features
Volts & Frequency to 500V
Insulation Resistance
Continuity Measurement
Loop /PSC Measurement
RCD Testing
Earth resistance Tests
Phase Sequence Indication
On-Board Memory
Interface for Downloading data

56. Summary
Resistivity measurement provides important data regarding the earth material prior to system design
Fall of Potential Test is the most widely accepted
Four pole measurement compensates for voltage drop in measuring cable
The 62% rule provides some guidance to the required distance for the temporary test spikes
Selective testing allows testing without disconnection
Summary of what’s been discussed so far.

57. Summary
Selective test is based on fall of potential test that speeds measurement and provides additional safety
Stakeless Testing is a fast method for multiple electrode systems
Two pole ground testing provides minimal information and should be used very cautiously
The Fluke 1623 provides the majority of the required functions for industrial users
The Fluke 1625 is the advanced ground tester for utilities
Summary of what’s been discussed so far.

58. Why should I invest on Earth Ground?
The WW market for Earth Ground is estimated to be $25 Million
With only two major US competitors (AEMC, Megger), with inferior product lines, there is no reason why Fluke shouldn’t have 40% market share in 3 years.
Fluke 1623 and 1625 are the most complete Earth Ground testers available anywhere
In the US, Megger & AEMC do not have the best products, they only have inroads into Utilities. Perfect value selling opportunity.
Your customers have been asking for it
It is core to our strategy (along with PQ, Insulation and Thermography)
Another opportunity to educate our customers about a product category. Take the high road, educate, convert to the best products. Repeat what you’ve done again and again.

59. Who to target?

60. Which product for which user?
Fluke 1653

61. 1625 worth the money?
Why would anyone pay € 650,- more for the Fluke 1625?
Utility customers will pay because they see value in the following advanced features:
Automatic Frequency Control (AFC) – identifies existing interference and chooses a measurement frequency to minimize its effect, providing more accurate earth ground values
R* Measurement – calculates earth ground impedance with 55 Hz to more accurately reflect the earth ground resistance that a fault-to-earth ground would see. Impedance is a frequency dependent measurement.
Adjustable Limits – for quicker testing.
Power utility technicians are interested in two things:
The ground resistance in case of lightning strike
The impedance of the entire system in case of a short circuit on a specific point in the line.

62. Product line-up Delivery content
Fluke-1623: Basic GEO Earth Ground Tester
Contains: Fluke-1623 tester, test leads, batteries, manual (GB, FR, IT, DE, ES, PT)
Fluke-1625: Advanced GEO Earth Ground Tester
Contains: Fluke-1625 tester, test leads, batteries, manual (GB, FR, IT, DE, ES, PT)
Fluke-1623/1625 Kit: Advanced GEO Earth Ground Tester Kit
Contains: (1) Fluke-1623 or 1625 tester, (4) stakes, (2) 25m cable reels, (1) 50m cable reel, (1) Sensing clamp, (1) Inducing clamp, all necessary connectors, test leads, batteries, manual, rugged carrying case

63. Accessories EI-1623: Selective/Stakeless Clamp Set for Fluke-1623.
Contains both the Inducing and Sensing clamp all necessary adapters
Already in the Fluke-1623 Kit.
EI-1625: Selective/Stakeless Clamp Set for Fluke-1625.
Already in the Fluke-1625 Kit.
ES-162P3: 3-Pole Stake Kit. (used for both the Fluke-1623 and Fluke-1625)
Contains: (3) Stakes, (1) 50m cable reel of wire, (1) 25m cable reel of wire
Already in the Fluke-1623 Kit/Fluke-1625 Kit.
ES-162P4: 4-Pole Stake Kit. (used for both the Fluke-1623 and Fluke-1625)
Contains: (4) Stakes, (1) 50m cable reel of wire, (2) 25m cable reel of wire
EI-162BN: 320mm Diameter Split Core Transformer
Used as a Selective clamp for ground loop resistance measurement around power pylons
Contains the split core transformer and all necessary adapters/connections

64. Marcom material Distributor product announcement Sales PPT
Value selling tool

65. Questions
and answers