INTRODUCTION Bert van Bruchem Program 1 Power Quality
INTRODUCTION Bert van Bruchem
Program 1. Power Quality intro 2. Application examples: • Applications • Technical background Break. 3. Products: • Features (HW/SW) • Value selling aspects
1. Power Quality intro What is power quality? Power Quality is a measure of how well a system supports reliable operation of its loads. A power disturbance or event can involve voltage, current, or frequency. – Power disturbances are defined in terms of magnitude and duration. – Disturbances range from transients to outages – When a power disturbance falls outside operating limits, equipment may be disrupted or damaged.
1. Power Quality intro How to deal with PQ.
1. Power Quality intro Common power disturbances Symptoms • • Power outages Tripping circuit breakers and ASDs High utility bills Flickering lights Equipment running noisy and hot Premature equipment failure Poor performance & unexpected shutdowns Lost data in electronics Causes • • • Voltage dips & swells Transients Noise interference Harmonic distortion Under / over voltage or current Voltage unbalance
1. Power Quality intro Causes of disturbances • Internal causes: Approximately 80% of electrical disturbances originate within a business facility. • External causes: About 20% of power quality problems originate with the utility transmission and distribution system.
1. Power Quality intro Inside the building Typical facility problems: • Loose connections • Arcing connections • Overloaded circuits and transformers • Unbalanced loads • Harmonics caused by modern electronics • Illegal neutral to ground bonds • Ground loops • Undersized or shared neutrals
1. Power Quality intro Utility generation & transmission Typical utility problems • • Fuses opening Protective relays and circuit breakers operating Power factor correction switching Grid switching “Reclosers” Equipment arcing or failure Downed lines (outage) Excessive demand (undervoltage, “brownout”) Example: When reclosers operate repeatedly to try to burn off tree branches or squirrels it causes repetitive voltage sags as seen here.
1. Power Quality intro Types of PQ work • Troubleshooting • Quality of service studies • Comprehensive PQ studies • Load studies • Commissioning
1. Power Quality intro PQ Customer segmentation Electricians or maintenance technicians whose primary responsibility is to maintain and troubleshoot the electrical system in their Industrial or Commercial facility Utility refers to the distribution division that delivers power from the Hi-V transmission substations to the consumer. Two groups within distribution do PQ Repairman (emergency crew) and Power Quality team Technicians responsible for installing, servicing, and repairing large equipment that is installed in a 3 rd party facility GE Healthcare, Otis Elevator, MGE Reduce downtime, RCM / respond to Commissioning, Respond to internal external complaints, system check, complaints / RCM Quality control respond to cust. complaints Firms that perform large electrical projects for facilities that may include either installation or service: Installers – run wire, install transformers and switchgear, etc Service – similar to Field Service, troubleshoot equipment problems at customer sites Commissioning, apply to cust. demands
1. Power Quality intro We differentiate between the following basic PQ applications: • Monitoring Quality of supply • Disturbance analysis • Network optimization • Predictive maintenance
1. Power Quality intro The benefits of Power Quality Monitoring ? • Knowledge about real Power Quality levels and trends (meet the regulators needs) • Planning data for investments • Monitor emissions from industrial customers etc. • Optimise and monitor contracts with supplier or consumer. • Supports optimisation of electric network • Monitor performance of protection devices.
1. Power Quality intro The benefits of Disturbance analysis. • Prevent similar disturbances • Reduce downtime • Competence and speed when dealing with customer complaints • Monitor performance of protection devices. • Improve maintenance
1. Power Quality intro The contribution towards Network Optimisation. • • • Prevent overloading Improve balancing of loads See trends Monitor performance of compensating systems Reduce energy bill
1. Power Quality intro Supporting Predictive maintenance • • • Detect and anticipate Check the critical parameters of motors Find the cause of dips / swells Monitor harmonic levels Locate the cause of hot spots ….
2. Application examples 1. “A bad reaction at the chemical plant” – Voltage unbalance – Voltage distortion and harmonics – Power system resonance 2. “Dips on the ski slopes” – Voltage dips – Flicker 3. “Gusty power at the wind farm” – Transients 4. “ Wasted power at the wastewater plant” – Energy consumption – Power factor
Bad reaction at the chemical plant
Chemical Plant: scenario Proactive maintenance and testing at a chemical plant uncover a problematic legacy • During a Pd. M procedure, a technician finds hot across-theline pump motors using a Thermal Imager • The feeders for the motors supplied both motor starters and newer drives The plant has been phasing out the older electromagnetic starters • No new motors or loads had been added
Chemical Plant: PQ analysis • Maintenance tech uses a Fluke 434 PQ Analyzer on the motor terminals and sees unbalance is within limits. • Tech measures voltage distortion and notes that 5 th harmonic is high. Voltage distortion is 14 %. • He determines an old PF correction cap had been switched in by mistake. The capacitor had been installed when all of the motors used soft starts. It had never been decommissioned! • The capacitor caused resonance at approximately the 5 th harmonic. Capacitor removed, problem solved!
Lessons and questions Lessons • Electrical issues than cause motor overheating: – Voltage unbalance – Overcurrent – Current unbalance (e. g. single phasing) – Voltage distortion • Combining across-the-line motors and motor drives on the same feeders can cause distorted voltage • Capacitors can turn harmless harmonic current into a problem Questions • Why did the electrician check voltage balance? • What are harmonics and why are they important? • What made the 5 th harmonic so high?
Why is unbalance important? Unbalanced loading Unbalanced current • Voltage unbalance causes inefficiency in a 3 -phase system. • To maintain voltage balance, each phase should draw approximately equal current. • Voltage unbalance causes current to flow in the neutral in wye systems. • Motors do not like to see more than 5 % voltage unbalance Unbalanced voltage
Harmonics and distortion • Consequences of harmonics : rotation éEach harmonic has its own rotation: Harmonic order Frequency Rotation 1 50 Hz + 2 3 4 100 Hz 150 Hz 200 Hz - 0 + 5 250 Hz - 6 7 300 Hz 350 Hz 0 +
Distorted waveforms Harmonic frequencies combine with the fundamental to form distorted voltage or current waveforms Total Harmonic Distortion (THD) expresses contribution of all harmonics a) A 212 A rms sine wave at the fundamental frequency b) A 28 A rms sine wave at the 3 rd harmonic Combination of (a) and (b) resulting in a distorted waveshape A spectrum display shows a breakdown of the components
Voltage distortion on motors • General: Higher frequencies cause heating due to eddy currents and skin effect • 3 th Harmonic causes neutral current • 5 th harmonic causes counter-torque • Harmonics can cause reonance Less than 5 % voltage THD desired
3 th harmonic
5 th harmonic
Power system resonance In this case the 5 th harmonic was close to the resonance freq so causing the problem
The resonance dilemma Remember!: motor windings + PF cap’s can mean resonance! How can I improve PF without creating a harmonics problem? . . …. Solutions: – Remove PF correction capacitors - need may be reduced since today’s ASD’s have/cause high DPF – Use capacitor systems designed for use with harmonic loads. – Active filters can improve DPF and substantially reduce harmonics
Dips on the ski slopes
Ski Café: The problem • Restaurant patrons at a ski resort complain the lights are flickering • Electrical contractor comes but voltage on DMM is OKE • Local utilitys is contacted, they connect a Fluke 1740 at the point of common coupling • The point of common coupling is at the bottom of the ski hill!
Ski Café: initial measurements • The Fluke 1740 Recorder : – some small voltage dips of a volt or two – No significant flicker – large current increases with the dips. • So, no problem for the Utility • The local contractor returns, with a Fluke 434.
Ski Café: tracing the problem 1 2 3
Ski Café: solution • The new deep fryer was allready installed over the summer. No one noticed the light problem during the summer, when daylight masked the problem. • The problem was due to the long feeders between the main switchgear • A separate feeder was installed for the fryer. Problem solved.
Lessons and key questions Lessons • Long or undersized wiring can contribute to voltage dips • Power recording can help zero in on the load causing the dips. Finding the culprit with the Fluke 345, 434, 1735. Questions • Why did running additional wiring solve the problem? • How did the electrician know where the problem was? • Restaurant customers complained that the lights were “flickering” but was this what PQ professionals call “flicker”?
What causes low voltage? • Too much system impedance and… • Too much load current A voltage dip is simply an incidence of low voltage that occurs over a period of ½ cycle to 1 minute. A voltage dip occurs when current is drawn over a short period.
System impedance (Z) Each conductor has some resistance. As current flows through each resistance, voltage drops Voltage at the load = source voltage minus all IR drops System impedance depends on: • Length of feeder and branch • Gauge of wire (diameter) • Source capacity
Dips and swells trending Trend voltage at the sensitive load • Capture dips and swells as short as a single cycle • Use cursor to read: • Real time stamp (Date: hour: minute: second) • Single cycle Min/Max • Simultaneous recording of voltage and current to isolate source of disturbances
Isolating source of disturbance Load disturbance: Downstream current inrush causes voltage sag Source disturbance: Upstream voltage sag causes little change or current drop
Flicker • Defined by standard IEC 61000 -4 -15 – Perceptible flicker in lighting caused by periodic voltage sags – Measured by a statistical “Lamp-Eye-Brain” model that duplicates how most people are affected by flickering incandescent lights • Causes – Loads that draw in periodic “gulps” (ex: arc furnaces, welders) • Basic measurements – PST -- A statistical figure derived over 10 minutes. A reading of 1. 0 causes flicker that can be perceived by 50 % of people – PLT -- A statistical figure derived from PST over 2 hrs – Represents the likelihood that fluctuations will cause annoyance Voltage changes of 0. 5 %, aprox. eight times per second, can causes perceptible flicker!
Flicker measurements A reading greater than 1 means that most people will perceive flicker in an incandescent bulb Measurements – Pst (1 min): Short-term flicker over 1 minute – Pst: Short-term flicker over 10 minutes – Plt: Long-term flicker over 2 hours 1745, 1760, 434 and 435 can tackle this item.
Gusty power at the wind farm
Wind Farm: scenario Transformers were failing much too quickly. Why? – 4 wind turbines share one transformer – Each turbine is equipped with a rectifier and inverter. The inverter produces 50 Hz regardless wind speed. – Transformer has had to be repaired twice in two years.
Wind Farm: utility investigation The utilities power monitors haven’t picked up anything. They hired an engineer who hooked up a Fluke 1760 and left it for a week Result: – Transients appeared on every cycle Advice: – The output of the inverter causes transients at the transformer – The engineer suggests: “replace the inverters!”
Wind Farm: investigation part II Next: • They did contact the inverter manufacturer • The manufacturer’s technician hooked up a Fluke 1760 and left it for another week
Wind Farm: solution • The designers used the data from the Fluke 1760 to identify a problem in the inverter outputs… …Faulty outputs • Action: The manufacturer makes a design change on the inverters and supplies new assemblies to the wind farm Problem solved!
Lessons and questions Lessons • Transients can dramatically shorten the life of equipment • Capturing transients and determining how often they occur can require long-term monitoring Questions • What are transients? • What causes transients and what are the effects? • How do we capture transients? • What can we tell about the source of a transient by looking at it’s shape? • Can you protect the system?
What are transients? A transient is a disturbance that lasts less than one cycle. We have different types: • Impulsive • oscillatory
Transients: cause and effect Causes of transients: • Utility transformer tap switching • Capacitor switching • Lightning • Motors switching off • Switch and relay contact “bounce” Effects of transients: • Damage semiconductor junctions • Damage Insulation • Coupling into adjacent conductors • Corrupt data signals
How do we capture transients? Most instruments that support transient capture use Envelope Triggering • Set a tolerance around an ideal sinewave • Any event that goes outside the envelope triggers the instrument to capture the waveform • You get to see voltage (and sometimes current) waveforms for all phases at the exact time of trigger • Cursors and zoom function help with the analysis.
Transient shape • Transients with series of oscillations (ringing): – Utility capacitot – Switching – Far away • Impules, high frequency transients – Local switching – Closer – Spikes/glitches Example: Narrow switching transient of -410 V (under the cursor) and voltage distortion due to SCR dimmer failure
Protecting against transients • They will always occur!! You can’t prevent them from happening. So you need to invest… • Transient Voltage Surge Suppressors (TVSS) • Uninterruptible power supply with built-in surge suppression • Isolation transformer
Wasted power at a wastewater plant?
Wastewater Plant: upgrades Situation: • The plant was adding new pumps, conveyors and controls • Can the existing system handle the new loads? • What is the present load on the system? • Electricians performed a 30 -day load study
WW Plant: load study • Electricians connected the Fluke 1735 Power Logger • Set it to record average power every 15 minutes • Recorded for 30 days
WW Plant: load study results • Capacity of the service was rated at 1000 amps • Top measured current was 700 amps = They had more than enough capacity to use the existing transformer and switchgear Everything hunky dory?
WW Plant: utility impact • After the pump installation, the utility called. Plant Power factor had dropped below 95 %. • Plant electricians used the Fluke 1060 Power Clamp Meter and read 93 % power factor! SO: Electricians performed a 1 -week energy study with the Fluke 1735 They confirmed that the PF drop coincided with the operation of the new pumps
WW Plant: correcting power factor • Engineers specified power factor correction at the new motor control centers • Power factor improved and the utility did not have to make any changes to the distribution system • Under their contract, the treatment plant could have been subject to stiff penalties for having PF lower than 95 % They successfully avoided the penalties
Lessons and questions Lessons • A load study will determine whether an existing system can support additional loads • Energy recording can corroborate metering equipment and isolate usage by specific loads • Energy recording can help manage utility charges for poor PF and peak demand Questions • What can you measure to help manage utility charges? • What are peak demand power factor and why do you get charged for them?
Managing the utility bill Utilities usually bill for: • Kilowatt hours (energy consumed) • Peak demand • Power factor
Energy consumption (k. Wh) k. Wh is an accumulation of the true power (k. W) delivered by the utility
Peak demand • Peak Demand determines how big the “electricity pipe” must be • Peak demand is the highest of consecutively-measured, 15 -minute or 30 -minute average k. W readings • The 434, 1735 and 1743 can average k. W over these intervals and report the highest
Leading and lagging, causes bad PF Current is in phase with voltage through a resistor Current leads voltage through a capacitor Current lags voltage through an inductor
3 Types of power VA = Glass VAR = Foam Three kinds of AC power • True power (W) - Does useful work • Reactive power (VAR) W = Beer Watts PF = Volt-Amps - Energizes motor magnetic field, charges capacitors - Inductive: amps lag volts - Capacitive: amps lead volt • Apparent power (VA) - System capacity
Displacement power factor (COS ) • A purely resistive load has a power factor of 100 % • DPF equals the cosine of phase shift between V and I • Higher reactive power means lower DPF • DPF considers only the fundamental frequency, not harmonics • Low PF restricts system capacity, can cause voltage drops and overheating Higher reactive power means greater system capacity (VA) is required
Total power factor (PF) and DPF PF = True power (watts) Apparent power (VA) Harmonic currents cause VA to increase, reducing the Total PF. • Total PF measures PF including harmonics. DPF only considers the fundamental. • Total PF is not necessarily equal to the cosine of the angle between V & I • Where harmonics are present, total PF is always lower than DPF. Correcting power factor in a system with harmonics requires special consideration – not just a simple capacitor (resonance!!)
Correcting power factor If most of the loads are motors (linear loads) then DPF can be corrected using capacitors. (Remember that a capacitor shifts the current in the opposite direction from an inductor) If there are significant non-linear loads on the system then a capacitor can make things worse! The appropriate correction must be determined by engineering analysis and may include passive filters or active conditioners.
Summary
Earth testing Practical Earth Testing Techniques and Measurement Instruments
Practical Earth Testing Content • Principles • Test Methods • Practical Measurement • Summary
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* Ground is a connection to Earth made either intentionally or accidentally *NFPA 70 -2000 (National Fire Protection Association)
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
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)
Earth / Ground Basics How do you connect to earth? Cable or tape Stake or rod Earth material
Earth / Ground Basics Spheres of influence
Earth / Ground Basics Attention! Potential gradients! Umeasure Potential gradients around the earth electrode can reduce the accuracy of measurements! Distance a Ground Potential Neutral ground, reference Umeasure The probe must always be placed outside this area! Typical distance: >20 m
Earth / Ground Basics Types of Grounding Systems • 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 Ground rod
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. Ground rod group
Earth / Ground Basics Types of Grounding Systems • 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
Earth / Ground Basics Types of Grounding Systems • A ground mesh consists of network of bars connected together, this system is often used at larger sites such as electrical substations. Ground mesh
Earth / Ground Basics Types of Grounding Systems For the purposes of this presentation the grounding system will referred to as ‘ground electrode’.
Ground Testing Methods What are the available techniques? • Resistivity • Fall of Potential – Three and Four Pole Testing • Selective Testing • Stakeless Testing • Two pole method
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.
Ground Testing Methods (1) Resistivity values for different earth materials
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
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 RE a . . . mean value of soil resistivity (W. m). . . measured resistance (W). . . probe distance (m)
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.
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 Three or four pole method 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.
Ground Earth Testing Methods (1) Testing Methods (2) Fall of Potential – 3 / 4 Pole Testing The E terminal of the instrument is connected to the electrode under test
Ground Earth Testing Methods (1) Testing Methods (2) 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
Ground Earth Testing Methods (1) Testing Methods (2) Fall of Potential – 3 / 4 Pole Testing The test spike C 2 is placed in the ground some distance from electrode under test (typically 50 meter)
Ground Earth Testing Methods (1) Testing Methods (2) Fall of Potential – 3 / 4 Pole Testing During the test the The voltage spike P 2 is instrument drives a placed in the ground current through the test some distance from From the current and spike, through the electrode under test voltage measurements surrounding earth and (typically 80 feet). made it is possible to returns through the Once the stakes are in calculate a value of electrode under test, place the test can ground resistance. the potential caused by proceed. this current is measured using the P 2 spike.
Ground Earth Testing Methods (1) Testing Methods (2) Fall of Potential – 3 / 4 Pole Testing A number of readings should be taken with the P 2 spike at different distances, say from 20 to 35 meters at 3 meter intervals.
Ground Earth Testing Methods (1) Testing Methods (2) Fall of Potential – 3 / 4 Pole Testing The distance of the P 2 spike is varied to ensure that it is positioned outside of the sphere influence of the electrode under test. When the P 2 spike is close to the electrode under test the measured value appears to be lower and as it becomes influenced by the C 2 spike the measured value rises. The optimal point of measurement is outside of the influence of the electrode and the C 2 spike. Taking a series of measurements and plotting these against distance produces the curve shown.
Ground Earth Testing Methods (1) Testing Methods (2) Fall of Potential – Creating the ‘S’ Curve The optimum value is that indicated on the flat part of the curve
Ground Earth Testing Methods (1) Testing Methods (2) The 62% Rule The 62% rule is a guide to how far away the P 2 and C 2 stakes should be placed from the electrode under test. The distances are nominally based on the depth of the electrode.
Ground Earth Testing Methods (1) Testing Methods (2) Distances for Electrode Arrays The 62% rule is a guide to how far away the P 2 and C 2 stakes should be placed from the electrode under test. The distances are nominally based on the depth of the electrode.
Ground Testing Methods (3) Selective Measurement Method • The selective method A current clamp is used is based on the fall of to isolate the test potential test current injected in to the • But: without the need electrodes under test. to disconnect the ground electrode under test. Test Current
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.
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.
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
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.
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.
Ground Testing Methods (4) The clamps are placed around the ground conductor
Ground Testing Methods (4) Stakeless Measurement Equivalent Circuit
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.
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
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.
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 • Widely accepted • When you see the characteristic curve you know you’ve got a good measurement. • 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 hardwired loop Two-pole Method • Convenience • Impossible to judge the integrity of the “auxiliary electrode. ” • Can’t be sure you are outside the area of influence
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
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
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
Choosing the right instrument Introducing the Fluke 1623 and 1625 Ground Testers
Fluke 1623 • Feature Summary • 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 IP 56 • 2 -Year Warranty • Customer • Electrical Consultants, Industrial • Application • Verification of earth resistance of electrical & communication systems.
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: >250 m. A, 48 V) • Earth impedance R* of high tension towers - for calculation of genuine short circuit current
Fluke 1625 - the expert instrument Additional features of Fluke 1625 • 2 pole AC resistance measurement - Resolution: 0. 001 Ohm - Measuring signal: 20 V / 250 m. A • 2 pole, 4 pole DC resistance measurement - Range: 3 k. Ohm, resolution: 0. 001 Ohm - automatic polarity reversal, adaptation of test period - short circuit current >200 m. A as per IEC/EN 61557 -5 , UM >4 V • 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 Win. GEO software
Fluke 1625 - the expert instrument Unique: R* - Earth impedance Measurement of complex earth-impedance at 55 Hz which determines the real short circuit current
Fluke 1625 - the expert instrument Unique: R* - Earth impedance Measurement of complex earthimpedance at 55 Hz which determines the real short circuit current
Chosing the right instrument Introducing the Fluke 1623 and 1625 Ground Testers
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 30 A 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
Clamp-On Earth Loop Tester GEO 30 LEM GEO 30 - Ground Tester / Current Meter Stakeless Ground Resistance Measurement I I Current amplifier U Rn Voltage generator Rx 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
Clamp-On Earth Loop Tester GEO 30 High quality, rugged carrying case High Quality measuring instrument Includes five language operators manual E/D/F/ES/IT Calibration loop for instrument check
Fluke 1653 • Target Customer – Professional Electrician / Testing Specialist • Top Line Model with Unmatched performance • Features – Volts & Frequency to 500 V – Insulation Resistance – Continuity Measurement – Loop /PSC Measurement – RCD Testing – Earth resistance Tests – Phase Sequence Indication – On-Board Memory – Interface for Downloading data
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 • 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
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.
Who to target?
Which product for which user? Fluke 1653
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.
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) 25 m cable reels, (1) 50 m cable reel, (1) Sensing clamp, (1) Inducing clamp, all necessary connectors, test leads, batteries, manual, rugged carrying case
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. – Contains both the Inducing and Sensing clamp all necessary adapters – Already in the Fluke-1625 Kit. • ES-162 P 3: 3 -Pole Stake Kit. (used for both the Fluke-1623 and Fluke-1625) – Contains: (3) Stakes, (1) 50 m cable reel of wire, (1) 25 m cable reel of wire – Already in the Fluke-1623 Kit/Fluke-1625 Kit. • ES-162 P 4: 4 -Pole Stake Kit. (used for both the Fluke-1623 and Fluke-1625) – Contains: (4) Stakes, (1) 50 m cable reel of wire, (2) 25 m cable reel of wire – Already in the Fluke-1623 Kit/Fluke-1625 Kit. • EI-162 BN: 320 mm 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
Marcom material • Distributor product announcement • Sales PPT • Value selling tool
Infrared Thermography An Understanding of our Fusion Technology A complete solution for your thermography needs
Infrared/Visible Blending Camera
Why Blend Visible and Infrared • Visible cameras : – Have more pixels which provides more image detail. Generally many millions of pixels. – Sense emitted and reflected radiation but primarily reflected which often provides sharper contrast. – Produces images with colors, shapes and intensities the same as seen by human eye.
Why Blend Visible and Infrared • Infrared cameras: – Sense temperature differences. – Can measure temperature. – For accurate temperature measurement, required to sense emitted radiation
Key Blending Requirements • Register images so they overlay each other. • Provide blending adjustment.
Spatial Registration Methods 1) Common optical path for visible and infrared sensor arrays
Common Optical Path Target Beam splitter Visible Sensor Lens Infrared Sensor
Spatial Registration Methods 1) Common optical path for visible and infrared sensor arrays 2) Single focal plane array with both visible and infrared detectors
Co-located Visible and Infrared Detectors Target Sensor with both Visible & IR detectors Lens
Spatial Registration Methods 1) Common optical path for visible and infrared sensor arrays 2) Single focal plane array with both visible and infrared detectors 3) Two optical paths and correct for parallax
Spatial Registration Methods 1) Common optical path for visible and infrared sensor arrays 2) Single focal plane array with both visible and infrared detectors 3) Two optical paths and correct for parallax
Parallax Geometry Visible Sensor Visible-Light Optical Path q Infrared Sensor d Infrared Optical Path d
Parallax Geometry (continued) Visible Sensor Visible-Light Optical Path q Infrared Sensor d Infrared Optical Path d
Parallax Geometry (continued) Visib le Sens or Visib le-Lig ht Op tical P Infrared Sensor d Infrared Optical Path d ath q
Parallax Geometry (continued) Visible Sensor Visible-Light Optical Path q Infrared Sensor d Infrared Optical Path d
Parallax Equation i Visible-Light Optical Path p q d Infrared Optical Path d p= qi q q = = æ 1 1ö æd ö d dçç - ÷÷ çç - 1÷÷ ø è f dø è f
Visible and Infrared FOV Target Scene Visible Sensor ' q IR Sensor Target Distance Visible FOV is approximately double Infrared FOV
Blending Example Infrared Image Visible Image Blended Image
Can Read Infrared Temperatures in Visible Image
Display Modes • Picture in Picture (Ti 40 & Ti 50) • Full Screen (Ti Family) • Color Alarm (Ti Family)
Picture in a Picture Camera 320 by 240 Display (dashed box)
Picture in a Picture 1280 by 1024 Visible Image (blue) Camera 320 by 240 Display (dashed box)
Picture in a Picture 1280 by 1024 Visible Image (blue & red) 160 by 120 Infrared, Visible or Blended Image (red) Camera 320 by 240 Display (dashed box)
Picture in Picture Example Visible Image Infrared Image Blended Image
Percent Blending 100 75 50 25
Full Screen Camera 320 by 240 Display (dashed box)
Full Screen 1280 by 1024 Visible Image (blue) Camera 320 by 240 Display (dashed box)
Full Screen 1280 by 1024 Visible Image (blue & red) 320 by 240 Infrared, Visible or Blended Image (red) Camera 320 by 240 Display (dashed box)
Full Screen Example Infrared Image Visible Image Blended Image
Color Alarm Example Color-Alarm Picture in Picture Full Screen
Low Contrast Target Example Infrared Visible Blended Visible Mark
Laser Pointer Spot Seen in Visible and Blended Image Visible Blended Laser Spot
Focusing the Infrared Automatically Corrects Parallax Out of Focus with Parallax Error In Focus Corrected for Parallax
- Slides: 166