Fluke Power Measurement - Power Quality and Power Logger
Fluke Power Quality Analyzers, Power Loggers, and Voltage Event Recorders are insurance against damage to important and sensitive equipment and downtime. Fluke Power Measurement Equipment can save your facility money too by identifying wasted energy. Fluke has a broad product selection in Power Measurement
- Power Quality Tools. Fluke offers an extensive range of power quality test tools for troubleshooting, preventive maintenance, and long-term recording and analysis in industrial applications and utilities.
- Power Quality Troubleshooters. Dedicated power and power quality clamp meters for frontline troubleshooting. Single-phase and three-phase power quality analyzers for predictive maintenance, quality of service compliance testing and load studies.
- Power Quality Loggers. Power loggers for characterizing power quality, conducting load studies and capturing hard-to-find voltage events over a user-defined period of time. They are perfect for 30 day load studies. Article 220 of the 2005 National Electrical Code's 30 day recording method is known as a load study. Learn more here: Fluke 30 Day Load Study Application Note
- Power Quality Recorders. Advanced power quality recorders for capturing comprehensive details of power disturbances, trend analysis and Class-A 'quality-of-service' compliance testing over a user-defined period of time.
Fluke Power Quality Selection Guide Document
![Fluke-Power-Quality-and-Energy-Tools-Selection-Guide]()
Click thumbnail to download PDF
What to consider when selecting Fluke Power Quality Meters. Watch the video
Why Should I Use Fluke Power Meters?
The reason is simple—unlike the single-functional products of other brands, Fluke’s power meter is a power monitor, an AC power meter and a power factor meter – all rolled in one. Its applications are many, including motor start-up analysis, detection of hotspots for effective wiring of equipment, verification of power distribution circuits and measurement and recording of power quality. Fluke’s power meter meets the new IEC Class A standards for flicker and power quality. The product range includes meters to monitor both single-phase and balanced three-phase power systems. So, whether you want to measure power factor or investigate disturbance, observe electric trends or enhance productivity, the Fluke power meter is a flexible, portable, must-have for your toolkit.
Patented Fluke Energy Loss Calculator![Fluke_Energy-Loss-Calculator]() |
Until now, capturing the cost of energy waste caused by power quality issues was a task for the most expert engineers. The cost of waste could only be calculated by serious number crunching, a direct measurement of the waste and monetization was not possible.
With the patented algorithms used in the Fluke 430 Series II products, waste caused by common power quality issues such as harmonics and unbalance can be measured directly. By entering the cost of energy in to the instrument, the cost is directly calculated. |
![Fluke 430 Series Phasor Diagram]() |
Unique Phasor Diagram in Fluke 430 Series is a useful installation tool.
The Phasor screen displays the phase relation between voltages and currents in a vector diagram. Waveform and Phasor display are also useful to check if voltage leads and current clamps are connected correctly. Quickly determine if clamps are wired to the wrong phases or wired backwards.
Click the image or link below for informative video.
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Check out this video from Fluke for help deciding which Power Measurement tool you need.
Fluke's What Power Quality Tool Do I Need To Do My Job?
Power Measurement Basics
The measurement of power and power quality includes the basic parameters of voltage, current, watts (kW, VA, VAR) or the basic parameters of energy (kVAh, VARh, kWh). When evaluating the power utilized in a system, there are many options when choosing what to measure and whether recording of the power system is required. Based on your individual goals, purpose and problems, you may desire to measure Power, Power Quality, Power Logging, Energy Management, Event Recording, Transients, Sags, Swells, or Waveforms. Many parameters must be considered when looking at power and power quality including AC or DC voltage, AC or DC current, watts, kW, VA, VAR, PF, THD, Harmonics, or energy including kVAh, VARh and kWh.
In addition to effectively performing basic tasks like measuring voltage, current, and power (wattage), power instrumentation varies considerably and you may consider ease of use, portability, and flexibility as well as capturing waveforms, event and parameter data logging and recording parameters.
One distinction to be made is the difference between Power Measurement and Power Monitoring. Measurement generally refers to real time/instantaeous readings, while Monitoring refers to recording/data logging.
Another distinction to be made is the difference between measuring and monitoring of Energy and Power. The requirements may have overlap but there are different resolution and accuracy needs:
- Energy. Generally measured in seconds with high accuracy, particularly for billing or billing disputes.
- Power Quality. Generally measured in microseconds. High accuracy is less important, though many instruments have revenue grade accuracy.
- Many Power Quality instruments can be used for energy measurement/monitoring, but not the reverse.
Each instrument may vary on capability, but the application and solution desired will dictate which instrumentation will be perfect for the application.
Wiring Systems
There are many parameters needed to resolve most power issues and problems in commercial, industrial, and residential settings. The first consideration is always the wiring system in question. The following configurations are some of the most common wiring systems used for measurement of power and power quality with additional wiring configurations available in specific instruments, including a three phase four wire Delta and others.
Single Phase Three Wire
This is the most common residential service in North America. Line 1 to neutral and Line 2 to neutral are used to power 120 volt lighting and plug loads. Line 1 to Line 2 is used to power 240 volt single phase loads such as a water heater, electric range, or air conditioner.
Three Phase Four Wire Wye
The most common commercial building electric service in North America is 120/208 volt wye, which is used to power 120 volt plug loads, lighting, and smaller HVAC systems. In larger facilities the voltage is 277/480 volt and used to power single phase 277 volt lighting and larger HVAC loads. In western Canada 347/600V is common.
Three Phase Three Wire Delta
Used primarily in industrial facilities to provide power for three-phase motor loads, and in utility power distribution applications. Nominal service voltages of 240, 400, 480, 600, and higher are typical.
The second consideration is the system itself and the type of Voltage and Current in the system. The following formulas are utilized for DC and AC circuits.
Power Measurement Formulas
For all DC Circuits and Resistive loads, P (power) is related to I (current) and V (voltage) and R (resistance) according to the following formula:
P = I2R = V2/R
For all AC circuits, including the source, inductive elements and capacitive elements, the formula used for defining power is shown as:
P = (½)VpIpcos(θ) = VrmsIrmscos(θ)
Where
Vp is the peak voltage,
Ip is the peak current,
Vrms is the rms voltage,
Irms is the rms in amperes, and
θ is the phase angle current and voltage. Cosθ is more commonly called
PF, or Power Factor.
For balanced 3 phase circuits, total power can be simplified to
P = sqrt(3)*V*I*PF
But most real world applications are unbalanced loads, so the sum of the individual phases will be more accurate.
PTotal = PA + PB + PC
In AC circuits, elements such as inductors and capacitors alter the direction of energy flow. The portion of power flow that, averaged over one cycle of the waveform, is known as “real power” (also referred to as active power). That portion of power flow due to stored energy is known as "reactive power”. In reality, most loads contain resistance, inductance, and capacitance, so both real and reactive power flows to the load. Apparent power is the vector sum of real and reactive power. Apparent power is the product of the root mean square of voltage and current and can be found displayed below in the Power Triangle.
Engineers, building managers, and consultants are concerned with apparent power, even though the current measured as reactive power does no work; it heats the system wiring, causing energy losses as well as possible heat and component failures. Energy and Power is costly. Wasting Power and Energy is not a goal for any user or owner of any system. Once problems are found, wiring systems, components, and generation equipment must be sized properly to handle all the current produced.
The Power Triangle
These three types of power -- true, reactive, and apparent -- relate to one another in what is referred to as the power triangle. The relationship between true power, reactive power, and apparent power is shown below as vectors.
- True Power is the horizontal vector. P (watts) = V*I*PF
- Reactive Power is the vertical vector. VAR = V*A*sin(θ)
- Apparent power is the hypotenuse of the right triangle below. The angle between the hypotenuse and the base of the triangle is the impedance phase angle. VA = V*I
- Power Factor PF = cos(θ) = Watts/VA
![power-triangle]()
Ideally θ = 0, P = V*A, VAR = 0
Voltage and Phasor Diagrams for AC Power
The sine waves below and the Phasor diagram display the relationship between the Voltage and Current in a typical measured system.
Understanding Resistive, Inductive, and Capacitive Loads
![diagram-resistive-load]() |
Resistive Load
Voltage and Current are in Phase
Power Factor = 1
Examples: incandescent light bulb, heater |
![diagram-inductive-load]() |
Inductive Load
Current lags Voltage. Out of Phase
Power Factor < 1
Examples: motors, most power systems |
![diagram-capacitive-load]() |
Capacitive Load
Current leads Voltage. Out of Phase
Power Factor > 1
Examples: power factor correction capacitors in devices, electrical panels, utility pole. Correction capacitors increase PF towards 1 for more efficiency |
What is ELI the ICE man memory mneumonic?
ELI the ICE man is an old memory trick to remember AC current, voltage, and phase angle relationships in inductive and capacitive loads worth mentioning now.
Assuming a purely inductive or capacitive circuit:
ELI reminds us that voltage (E) in an inductive circuit (L) leads the current (I), by 90 degrees.
ICE reminds us that current (I) in a capacitive circuit (C) leads the voltage (E), by 90 degrees.
In a purely resistive circuit, the voltage and current arrive at the same time to the same point.
Transducer Selection
Transducers are used to measure electrical circuits that are beyond the capability of the instrument. There are two types for power measurement: Voltage and Current.
In low voltage applications, the instrument can be connected directly. Potential Transformers (PTs) are used to step down the voltage in medium and high voltage applications.
CTs are used to measure AC current using an inductive principle, which more can be learned about in our Current Clamp Adapter / Current Clamp section by clicking this link
Current Clamp Adapter / Current Clamp.
- Current Transformers for power instruments are used to step down the AC current to a safe and manageable value and is typically 5A or 1A full scale.
- Current Transducers for power instruments convert the AC current measurement to a DC voltage and is typically 1.5 V or 3 V.
- Core type is an important selection:
- With solid core CTs, the conductor must pass thru the donut, so the electrical connection must be broken to install. Typically they are less expensive and used in new installations and permanent installations where regular monitoring is needed.
- Split core CTs open and can be clamped around the conductor in situ. Split core are available in two types:
- Clamp on style with a rigid clamp and opening jaw.
- Flexible style based on the Rogowski principle can be easily manipulated to fit tight spaces. They typically require external power and common lengths are 24, 36, and 48 inches. One trick to amplify low amperage signals, when using flexible CTs, is to wrap the CT in two loops but remember to double the span in the instrument.
When selecting a PT or CT, size it appropriately for the circuit and that it has the proper signal compatibility for the instrument, especially if not supplied by the instrument manufacturer. It could act as a low pass filter. Select ones with a high frequency range. Poor selection can reduce accuracy and bandwidth.
Power Quality
Poor power quality can be extremely expensive since it increases energy costs. That may include excess power usage as well as being penalized for increasing poor power factor or higher peak demand utility charges that might not be necessary. Poor power quality takes its toll on equipment. This will increase the cost of maintenance and repairs. Replacement of premature failures of equipment as well as the cost of the diagnosis and replacement of this equipment can be extremely costly.
Although every user has a primary purpose in mind when checking and evaluating Power and Power Quality, the most common purpose is the measurement of how reliably and efficiently your systems operates under load. We usually begin to evaluate our systems response and use of electricity, but in utilizing power instrumentation, we may need to evaluate many parameters, including, but not limited to:
- Transients
- Voltage, Current and Frequency Disturbances
- System Dips, Sags, Swells
- Harmonic Distortion
- Unbalances
- Flicker
System problems are evaluated based on measuring the source and direction of the impending problem as well always measuring magnitude and direction. The timing of the problem is always important, whether one microsecond or one hour in length
Normal system analysis usually involves the measurement of voltage and frequency deviations. Most instrumentation will detail the range of measured values and the safety category capability of the instrumentation. Please use the link below to see the most recent advance in NFPA 70E.
Who sets the rules for electrical testing and safety?
Typical Applications for Power and Power Quality Measurement
- Verification of power distribution circuits
- Measurement and recording of power system quality (kW, VA, VAR)
- Energy metering (kVAh, VARh, kWh)
- In plant troubleshooting of power distribution panels and individual machinery
- Monitor pad mount transformers
- Determine harmonic problems originating from source or load
- Monitor phase unbalances
- Determine transformer K-Factor
- Setup and troubleshoot variable frequency drives and UPS systems. Verify correct operation by measuring key power quality parameters
- Harmonics Measurements. Uncover harmonic issues that can damage or disrupt critical equipment
- Inrush capture. Check start-up current where spurious resets or nuisance circuit breaker tripping occurs
- Load studies. Verify electrical system capacity before adding loads
- Energy Audits
- Predictive Maintenance
- Long Term Intermittent Analysis
Considerations when selecting a Power Quality Analyzer
- Sampling rate and data storage rate
- Accuracy
- Bandwidth
- # of channels
- Are transducers included or purchased separately?
- Triggering algorithms and analysis techniques
- Memory
- Communications
- Ease of use
- Battery life
Harmonics Definitions and Measurements
Most concerns for any Power quality system evaluation will include the measurement of Harmonics. Harmonic Analysis involves the real time existence of waveform distortions. As a definition, harmonic frequencies are odd end even multiples of the 60Hz (hertz) first fundamental frequency. The second harmonic is at 120Hz, (twice the fundamental); the third harmonic is at 180Hz and so-on. When all the frequencies are summed, the result is the measured waveform. Any deviation from a pure sinusoidal (sine) waveform indicates the existence of harmonic components. Harmonics may exist in any short or long time sequence, but harmonics only cause damage when they exist for a significant amount of time.
One reason harmonics cause so much damage is that they generate excessive heat. Some of the problems that may be caused by excessive harmonics are:
- Equipment failure
- Overloading of Power Apparatus
- Overloading Systems
- Instrument and Component Lifespan
- Degradation of Power Quality
- Unreliable Operation of Equipment
- Data Loss in Digital Equipment
- Overheating of neutral conductors and connections
- Overheating and premature failure of supply transformers
- Failure of Power Factor-correcting capacitors
- Excessive electrical noise
- Power interruption causing tripping circuit breakers and blowing fuses
- Power loss (due to heat loss in cables)
- Building wire failure
- Failure of Electronic Equipment
- Interference
Although Current and Voltage Harmonics exist and both may be detrimental to the system, current harmonics tend to be less severe as they extend from their point of origin; however, Voltage harmonics have a tendency spread and can damaging at a greater distance from their origins.
Harmonic Distortion
Once the source of the harmonic distortion is found, the process of determining how to prevent it and control it may begin. Following is a listing of common sources of harmonics typically listed as Non-Linear Loads i.e.,
- Personal computers and other microprocessor-based devices
- Uninterruptible Power Supplies (UPS)
- Fluorescent lighting (especially newer electronic ballast types)
- Battery chargers
- Static power converters
- AC heating controls
- AC and DC motor controllers
- Rectifiers
- Power supplies used in electronic and office equipment
- Power electronics such as Variable Speed Drives
- SCR-controllers
- AC/DC static converters
- Arc furnaces
- Welders
- Saturated Transformers
- Intermittent electrical noise from loose connections
What are Triplen Harmonics?
One of the most troublesome harmonics usually is the third harmonic and its odd multiples of the third. This is referred to as the Triplen Harmonics (3
rd, 9
th, 15
th, 21
st, etc.). These harmonics seems to be the most dominant and always have the highest magnitude and cause the most damage since the currents are additive on the neutral. The fifth (5
th) and eleventh (11
th) harmonics are also cause for concern since they will attempt to drive a 3-phase motor in the opposite direction and will possibly cause nuisance tripping and overheating.
It is important to establish the system evaluation; the harmonics that may be prevalent, any transients, sags or swells and then attempt to find a mitigation approach to reduce problem areas.
Sometimes it is not evident until testing is done and measurements are made that small equipment added in a system over time may be the very culprit in producing damaging harmonics.
Click on the images below to download excellent Power Quality resources from Fluke.
Power Quality Measurement World Standards
- IEEE 1159 and IEC 61000-4-30Power Quality
- IEEE 519 and IEC 61000-4-7 Harmonics
- IEEE 1453 and IEC 61000-4-15 Voltage Flicker
Power Energy Logging
Fluke Energy Logger Overview
Power and Energy Loggers measure and save (data log) important parameters, i.e., Voltage, Current, Frequency, Harmonics, Watts, VARS, VA and Energy (kWh and kVAh, kVAh), Power Factor & Displacement Power Factor (DPF), Crest Factor, THD, and waveforms.
In these modern days, rising costs of most goods and services force us to continually evaluate and modify our purchasing habits in order to obtain the greatest efficiencies. Having and maintaining this information at our finger tips allows us to react and plan. It is also understandable that as Power and Energy costs increase, we need a mechanism to be able to evaluate our needs and power and energy use. Understanding what is needed and what is being used gives us greater insight into the manner in which we may react and plan our use. The measurement of “how much and when” regarding power and energy is vital and the instruments used are Power and Energy Loggers.
Power loggers are chosen on the basis of information desired and report capability as well as parameters required, length of time for recording values, hand-held, portable, bench top, with or without displays, wiring system (single phase or three phase), and related problems in the system. Many loggers, both Energy and Power, may be programmable and chosen based on the environment capability. There are many alternate displays that may be chosen. Below are examples “only” of a digital display as well as a graphical display. Many Instruments offer both utilizing existing display panels as an integral part of the Instrument as well as software used with a laptop or PC.
Here are examples of a graphical display of a Harmonic distribution. Certainly helpful in determining system problems and establishing a mitigation plan.
![Power Harmonics graphical display]()
![Power Harmonics graphical display]()
Graphical Display Examples of Power Harmonic Distribution
Below is an example of a Digital Display of Total Harmonic Distortion of Voltage in all three phases.
![THD digital display]()
THD Digital Display Example
The primary reason for the use of data loggers, may vary, whether measuring Power or measuring Energy in the system, these may be some typical justifications:
- Load Studies. Understanding the system or circuit load capacity before attempting to add increased loads
- Energy Assessments. The ability to evaluate energy used before corrections and after corrections have been made. The establishment of an Energy Profile is required when looking at system data
- Harmonics Measurements. Harmonics existence can be dangerous and damaging. Understanding the existence and possible mitigation required is an advantage
- Voltage Event Capture. Seeking any information that will aid in system evaluation, i.e. surges, sags, swells, transients. etc.
One of the primary factors to consider is the time base and total length of recording for each value. It is common to consider whether the information being recorded is available in real time or in recorded intervals. Data may be collected from a time reference from every second to days and even months. This selection is based on existing problems, intermittent or average values, and costs. Utilizing a logger system offers a comprehensive picture of the Power and Energy Systems and is now available to evaluate and solve Power and Energy problems.
Applications for Power Energy Logging
- Measurement and recording of power system quality (kW, VA, VAR)
- Energy metering (kVAh, VARh, kWh)
- In plant troubleshooting of power distribution panels and individual machinery
- Monitor pad mount transformers
- Determine harmonic problems originating from source or load
- Monitor phase unbalances
- Determine transformer K-Factor
- Setup and troubleshoot variable frequency drives and UPS systems
- Verify correct operation by measuring key power quality parameters
- Harmonics measurements- Uncover harmonic issues that can damage or disrupt critical equipment
- Inrush capture. Check start-up current where spurious resets or nuisance circuit breaker tripping occurs
- Load studies. Verify electrical system capacity before adding loads
- Energy Audits
- Predictive maintenance
- Long Term Intermittent Analysis
Here are additional examples of display options. On the left, the wiring and phase choice are shown, On the right, the details of Voltage, Current and Phase angles are shown on the Phasor Diagram.
![voltage, current, and phase angle display]()
![phasor diagram]()
Additional Power Display Examples
Power and Energy Loggers may have a multitude of displays and may be chosen using a variety of formats including Analog Data, Digital Data, Digital Graphics, Multiple Screen, Single Waveform, Multiple Waveforms, General Report generation, and Specific Report generation. It is important to realize that Power and Energy Loggers may also be chosen for building and system monitoring, as well as residential and overall energy audits. For most data logging systems, all important power and energy data is measured, recorded, and possibly analyzed. This will allow you to understand utility costs, improve efficiency, install energy savings devices, and explore alternative energy solutions. For a complete review of the choices you have, please call one of our Power and Energy Specialists for assistance.
Voltage Event Recorders
Voltage Event Recorders display, record and report voltage anomalies. These may include Sags, Swells, Spike and Transients. The units are offered from as simple as supplying a non-display alarm with software report capability to complete recordings of waveforms, transients, sags and swells. Typically they have come supplied with a line cord to plug directly to an AC mains outlet (110 VAC, 220-240 VAC)
Here is a typical graphical voltage display as well as a tabular view of events