Successful Power Monitoring is a Process

Michael DaishVice President SalesSummit Technology Inc.

Power Monitoring is a ProcessIntroductionWhy is monitoring a process?What are the tasks?Why studies go wrongChoosing instrumentationData collection, retrieval, & analysisDocumentation & reportsConclusions

Why is Power Monitoring a ProcessPower studies have a beginning, middle, and end.Connecting and set-up, correctly, safelyMeasurement over time, loggingAnalysis and Reports the end gameMonitor is central to the process data collection toolSoftware tools complete the process, analysis, report

What do we want to accomplish? Define the problem you want to solve, examples:

I need to add more loads will my panels and circuits support the new additions?We need to reduce energy consumption I need to perform an energy audit to evaluate energy savings opportunities.How are the energy savings measures we have implemented performing?This transformer is very hot is it overloaded, or are high harmonics the cause?My (machine/process) is operating erratically is power quality the cause?When the HVAC (or motor or other equipment) turns on the breaker trips.Im commissioning a UPS and need to verify its performance.I want to perform regular diagnostics on our motors as part of a predictive maintenance program.

etc.

Power Study TasksLog V & IPower & EnergyPower Quality sags/swellsPower Quality high-speed transientsHarmonicsFrequencyFlicker

Choosing Right Instrument

Instrument Types and TrendsMultiple vendors = choice difficultMicroelectronics progress = lower costMore processing powerLower cost memory = more storageVariety of communications methodsBlack-box, tablet, hand-heldPQ features added to permanently installed metersStandards based or trouble-shooting

Instrument Types

Instrument Types

Instrument Types Present

Why power studies go wrong!Bad planningIncorrect connectionsWrong set-upPower cord or leads come offTampering

To Display or Not DisplayUnattended long-term monitoring and logging does not require a displayFor long monitoring periods no one is looking at the monitorAnalysis done off line Use PC as display for analysis and reportsGood security small size, less conspicuous

Attended short-term monitoring sometimes requires oscilloscope displayWitness conditions as they occurForcing events, changing of waveformsUsually during commissioning and set-up of equipmentPoor security video game

Safety Categories

Overvoltage Protection Categories Overvoltage withstand capabilityCAT II 600V4000VCAT III 300VCAT III 600V6000VCAT IV 300VCAT III 1000V8000VCAT IV 600VCAT IV 1000V12000V

Safety: Connecting SafelyCAT IV rating - highest level of transient overvoltage (8,000 V over voltage at 600 Vrms service)Verifying connections by experienceIndicator lights go, no goDisplay phasors, rotation, polarity, waveformCTs self-identifyIntelligence SureStart checks all conditions

Waveform Capture

Spot ChecksLCD Meter displayLabeled buttonsInstant readings

Connection Check ListTypes of Errors that may be presentOne, two, or three voltages not connectedOne, two, or three currents not connected to sourceOne, two, or three currents not connected to measuring systemTwo or three connections to the same voltageTwo or three connections to the same currentVoltages misidentifiedCurrents misidentifiedOne, two, or three current sensors backwardsTwo voltage connections switchedTwo current sensors switchedAll voltages rotated one position leftAll voltages rotated one position rightAll currents rotated one position leftAll currents rotated one position rightOne phase not presentTwo phases not presentThree phases not presentOne phase offered as two or three phasesOne phase shorted to neutral or groundTwo phases shorted to neutral or groundNeutral not connected to groundNon-standard voltage due to improper loadingNon-standard voltage due to power system problemNon-standard frequency due to power system problemNon-standard phase shift between phases due to power system problemCombinations of the above listed errors

SureStart For Successful Studies

Algorithms check all voltage and current connections Advises user of connection errors, setup

SafeConnect Monitor power without exposure to high voltagesNo need to wear special gloves, eye-protection, or flame-retardant clothing. No need to power down. No need to put up protective barriers or warnings.Quick setup and teardown of monitoring sessions on live power. No need to remove panels. No need to deal with hooking up current probes in tight or inaccessible spaces. Periodic maintenance measurements.No switched phases, reversed probes, or dead channels. Permanent connections means the data is right when you return 1 month later.

The Mighty Hand-HeldPower LoggerPower and Energy AnalyzerPower Quality and HarmonicsMotor DiagnosticsPS250 PS2500 PS3000 PS3500 PS4000 PS4500

The Mighty Hand-HeldPower LoggerHarmonics optional

The Mighty Hand-HeldPower LoggerPower and Energy Analyzer

The Mighty Hand-HeldPower LoggerPower and Energy AnalyzerPower Quality and Harmonics

Data Retrieval MethodsSerial cable RS 232Ethernet via serial-to-Ethernet converter USB via serial-to-USB converterWireless - BluetoothSD Memory card (256KB 2 GB)

Log V and I

Log Tabular Data Export to Excel* StartStartVanVbnVcnIaIbIcWaWbWcVAaVAbVAcPFaPFbPFcFreq* DateTimeAvgAvgAvgAvgAvgAvgAvgAvgAvgAvgAvgAvgAvgAvgAvgAvg7/18/200211:33:57270.5268.2270.323.44822.66423.6722835299529806346.460806401.60.450.490.47607/18/200211:33:58270.7268.2270.124.65623.12824.323433322232386675.262046566.40.510.520.4959.97/18/200211:33:59270.3268270.524.68822.90424.2323473305032356668.86139.26553.60.520.50.49607/18/200211:34:00270.7268.1270.724.50423.06424.0323339313930976630.461846505.60.50.510.48607/18/200211:34:01270.5268269.924.2822.9623.8323217311529396566.46154.46433.60.490.510.46607/18/200211:34:02270.4268.1269.924.45623.11224.0243346317330626611.26197.66486.40.510.510.47607/18/200211:34:03270.8267.9270.524.54423.248243365322630196649.66230.464920.510.520.4759.97/18/200211:34:04270.4268.4270.724.77623.3624.1363408317830336700.8627265360.510.510.46607/18/200211:34:05270.7268.6270.824.62423.03224.23403299631466668.86187.26553.60.510.480.48607/18/200211:34:06270.4268.2269.924.5622.90424.1843351298731566643.261446529.60.50.490.4859.97/18/200211:34:07269.6267.5269.924.35222.85624.1363262308730336566.46114.46514.40.50.50.47607/18/200211:34:08270.3267.3269.924.11222.54423.6563212300728906518.460286385.60.490.50.45607/18/200211:34:09270.2268.3270.724.44823.20823.8163277318529006604.86228.86449.60.50.510.4559.97/18/200211:34:10271.1268.527124.41623.423.9923289325630136617.66285.66503.20.50.520.4660.1

Power and Energy

KWh

Harmonics

Harmonics

RMS Events Sags/Swells

Waveform Sags/Swells

RMS Events Current Inrush

High-Speed Transients

High voltage probesHigh voltage probes for 5KV or 15 KV

Motor Current Signature Analysis Evaluate motors while running Rotor/armature health Stator mechanical/electrical health Field coil faults Bearing health Eccentricity Loose connection problems Induction, synchronous, DC, wound rotor and induction with VFD type motors.

Reports and Documentation The end game! Print individual graphs Highlight peaks and behavior Tabulate results minimums, maximums, and averages Filter results Edit text and graphs Wizard to compare two results surveys before and after! Save as pdf, doc etc.

Reports and DocumentationAdd labels to draw attention to behavior

Reports and DocumentationTables and graphs compiled automatically

Reports and DocumentationFilter report

Reports and DocumentationComparing two studies

Reports and DocumentationComparing two studies

Safety: NFPA 70E Arc Flash Hazards

CAT IV and Bluetooth for Safety

Safety: Remote PDA Operation

Safety: Leaving monitor behind unattended

ConclusionPower monitoring is a processConnect correctly and safelyV & I data logging most common study Energy analyzer addresses 60% of studies Sags/swells are most common PQ problemHarmonics and high-speed transients less significantDisplay need depends on attended/unattended operationNew hand-held analyzers pack high performanceOptions for high voltage, high freq noise, motor diagnosticsReport writer completes the jobNFPA 70E has changed electrical maintenance & testingBluetooth for remote control by PC or PDA

Welcome to Power Monitoring is a Process. First Id like to tell you a little about myself. Ive been involved in power quality since 1982 and power monitoring almost exclusively since 1985. Ive been fortunate to have been involved with many of the innovations that have occurred in power monitoring over the last two decades. Im going to share my experience with you in this presentation.Ive also been fortunate in traveling to many parts of the world and have seen how other countries monitor power and energy so I like to think that I have acquired an international perspective. Most of my experience has been in monitoring power quality and solving power quality problems.Ive noticed many wonderful advances in power monitoring technology over the last few years. The good news here is that you can now get instruments with high performance at prices that are about half of what they were ten years ago. However, there is not much distinction between the various monitors in the market place in terms of the measurements they make. Ive noticed that customers are more concerned with how the PC software works, what kinds of reports it can produce, and how easy both the software and the instrument are to use.At Summit Technology we have produced a range of highly portable (i.e. hand-held instruments) at various price and performance levels. Id like to share with you our philosophy behind the development of our family of hand-held analyzers and how they solve real world problems. This presentation posits the idea that monitoring is a process. We are going to look at the elements of the process and the role of the power monitor in this process.Id like to tell you what to expect in this presentation. Heres how its going to go. After this introduction I will begin a conversation on what we mean by the process of power monitoring. Well describe what the typical power monitoring tasks are, what the various types of power studies that are commonly carried out, and in what proportion. We will see that the type of power study to be performed will dictate what the best type of power monitor is to use.Our intention is to give you a perspective on what we consider is important when it comes to the selection and use of power monitors. We are going to discuss how to define the problem, and how that will guide you in performing the right type of survey, with the right tool. Next we will discuss why power studies are unsuccessful and what can be done about it.We will review the present state-of-the-art of development of monitoring instruments, and how they have evolved to where they are today.There are some practical matters to consider such as how to connect to power, and how to connect safely. We will then cover the various methods of retrieving data and the software tools that are available to analyze the data. The end game in a power survey is issuing a report with a summary of the power survey results along with recommendations and comments. At the conclusion of this presentation you will be left with a good overview of the current state-of-the-art of power monitors, and how this manufacturer is addressing the entire end-to-end process of successfully performing power studies.

Why do we say that power monitoring is a process? Consider that a typical study has a beginning, middle, and end. The beginning of the process involves connecting the monitor to the circuit to be studied; i.e. connecting the voltage leads and current probes to conductors. Before monitoring can begin the monitor needs to be set up correctly for the appropriate power configuration, such as wye or delta, and must be told what to record. The middle part of the process is the measurement and recording of data. This is where the performance of the monitor itself becomes important; what it measures, how long it should measure for, when to record, and how fast it makes its measurements. Monitor performance is very important and central to the entire process. The role of the monitor is in the measurement and data collection.The end of the process involves the analysis of the measured data and preparing a report or summary document. This is where the PC software analysis capabilities are important. We like to refer to the final report as the end game! The point at which we can say the study is complete is the completion of a report with a summary and examples of the measurements, and graphs, along with conclusions and recommendations.

Before embarking upon a power study, good planning is vital. A good plan begins with a declaration of what we want to accomplish. Here are examples of just a few statements that articulate what we want to accomplish and why. This list is clearly not an exhaustive one. You can come up with many examples of your own.The point here is to understand the objectives of the power study. In other words What will the big result look like when the study is complete? To look at an example, take the common application of monitoring voltage and current at a load or breaker panel. We might be interested in adding more circuits or more loads to the panel. Before adding them we would like to know how much capacity is spare (or available) to allow the addition of more loads and stay within the panels current capacity rating for safety. It would make sense to monitor the panel for at least 24 hours, preferably a weeks business cycle, so we can understand the behavior of the existing loads on the panel before we add new loads. The monitor will track the current consumption so that we can see when it reaches a maximum, and therefore whether the maximum value still allows for additional loads to be added.After we have added loads we should monitor again to observe the changed behavior of current consumption. Is it still within the panels capacity? Or have we inadvertently created a new problem such as voltage imbalance? And so on.One of the uses of a power monitor is to prove that the power quality is OK. With monitors that have high sampling rates we can detect RMS voltage dips down to a half cycle and voltage transients (spikes) as fast as a few microseconds. To reiterate, you must have a plan of action before beginning the study.If we look at the power study tasks that monitors are used for they can be broken down as shown. Often, studies will involve a combination of monitoring several parameters. From a poll we have conducted amongst our customers, electrical service engineers and technicians, we find that a third of all studies are to simply log voltage and current activity. We have just seen the need to find the maximum and minimum levels of current when determining whether to add loads to a panel or circuit, or to study what the effect has been when we have added a load. The RMS voltage log data will show how well the voltage is regulated and if current activity, loads turning on and off, is creating sags.The next most common type of studies are for measuring energy use, usually for cost savings reasons. Some utilities impose power factor penalties or peak demand charges, so we need to understand not only the amount of energy being consumed but the energy use profile. Sags and swells are the most common types of power quality problems. An RMS profile will indicate if low voltages occur. Higher speed sampling is necessary to determine more precisely when events occur and whether they are load or utility related. This higher level of detail shows the RMS event or wave-shape over a few seconds or cycles.Harmonic issues are less common but we still need to be aware of the potential for harmonics problems. High-speed transients are not a big concern unless you live in a high lightning activity zone or have machinery turning on or off in the vicinity.Frequency studies are rare since the utilities do a good job of regulating frequency. Flicker is a very rare consideration here in the US, its more of a concern in Europe.With the knowledge of these statistics, users can now choose or buy the appropriate instrument for the tasks we have to perform. Most studies do not need an expensive power quality monitor. Instruments that measure everything cost the most. If we rarely have to perform a harmonics study or a transient study then we might want to consider lower cost meters that log, or we might consider renting instruments for those few occasions instead. We will return to this chart later when we talk in more detail about instrument types.Before we discuss choosing a monitor lets first survey the market (these are our opinions). Presently there are over 30 vendors of power monitors, all with very similar measuring capabilities, making a choice seem difficult. The trend in microelectronics has resulted in increased computational power in smaller size at lower cost. This has spurred the introduction of monitors by new vendors attempting to leap frog each other, more on price than capability. Advances in memory technology has also meant increasing the storage capacity. We have the ability to store more data for longer periods, and with greater detail. These trends (storing more, performing more calculations, sampling at higher speeds etc.) have resulted in multifunctional monitors that make multiple measurements simultaneously. A good trend but how do we choose between them?One helpful way is to look at how they are packaged. We can categorize monitors into three package types: the black box, the tablet style, and the hand-held. I will describe these in more detail in the next slides. The ability to communicate to a PC is now common since it is has become standard practice to perform data analysis and report writing off-line on a PC. The communications available are serial cable, Ethernet, and recently, wireless.Another important trend is that many of the features that previously were only found in portable PQ meters have been implemented in permanently installed meters for switchboards, and even revenue meters.Finally, another important trend is the incorporation of international standards into monitoring. For example, EN50160 is a European standard that prescribes the level of power quality delivered by the utility to their customers. Monitoring to the EN50160 standard only gives a pass/fail result and so it should be kept in mind that the standard is designed to qualify whether the level of power quality from the utility meets this standard. The standard is in no way intended to help troubleshoot what the power quality problems are and how they can be remedied. Here we can see the various package styles of the most popular monitor types on the market today. We have tablet style monitors with a graphic display and keypad, the black box style which has no keyboard or display, and the hand held that has buttons or keypad and an LCD display.Here we can see the various package styles of the most popular monitor types on the market today. Tablet StyleTablet style monitors are characterized by having an integrated graphic display and keypad to program the meter and are about the size of an 8 x 11 sheet of paper. Black BoxThe black box style has no keyboard and no display thus the anonymous black box! It must be set up and the measured data collected by using a PC.Hand-heldAs the name suggests the hand-held meters are characterized by their small size; they fit in one hand. Their low weight means that hand-helds are highly portable. Hand-helds may have a single on-off button or a complete keypad, and may have an LCD or graphical display.This table provides a comparison between the hand-held, the tablet style, and the black box. The highest performance, i.e. the meters that make the most measurements, at the highest sampling rates and with the most storage (memory) capacity comes with the highest cost the black box type.Hand-helds are the most portable, being smallest and lightest They offer excellent value by providing good performance at the lowest cost. They are always the best choice when simple logging is all that is needed. However, the most recently introduced hand-held meters have taken advantage of the advances in microelectronics and offer good power quality measurements to capture sags, swells, and transients, as well as measure harmonics. The main attraction for the tablet style is the integration of a display and keypad so that set up and viewing of events and measurement values can be displayed immediately without connecting to and firing up a PC. The display also permits the tablet type to behave as an oscilloscope to view waveforms in real-time. Lets explore the pros and cons of the integrated display. We want every power study to be successful the first time. In our experience the reasons why there is no data, or the data is incorrect or worthless, are due to: bad planning, incorrect connections or set-up, power and measurement leads coming off, and tampering.Bad planning probably accounts for a third of bad studies. We have already stressed the importance of clearly articulating the objectives of the power study before you connect it. The next two major reasons are incorrect connections and/or incorrect set-up of the monitor. Set-up of monitors has always been problematic. It can be confusing to know how to program trigger levels and manage memory. One solution is the full-disclosure type of monitor that does not require any user programming; the user just tells the monitor when to start and stop, and all measurements are made automatically.A good alternative approach uses pre-configured set-up scenarios that are available as files that can be recalled depending on the situation to minimize the possibility of making set up errors.Occasionally, the power cord to the monitor can be pulled out and the monitor shuts off after its battery runs out. Some monitors can power themselves from the voltage service they are monitoring eliminating the power cord problem. The best solution is to ensure that the monitors connections are secure. This would also apply to the monitoring leads to make sure they dont come adrift half-way through the study. Tampering and theft does occur. Hand-held monitors are better for security. Being much smaller they can be more easily hid from view in equipment voids. Tablets pose a higher risk since their video-game-type color display attracts attention.

Lets discuss the merits of a built-in graphics display, when it is useful? Most power surveys are done over long periods of time, typically 24 hours, a week, or a month. For the majority of that time the monitor is unattended, no one is looking at the display. After the monitoring session data is downloaded to a PC, for analysis, then the need for a display is less important. It is helpful to check connections at the outset of a monitoring session to view waveforms and phasors on a display. Even then its possible to misinterpret the display and make errors. Intelligent software is now available that checks all channels for correct connections and advises the user of errors, lessening the need for a display on the meter, and (we assert) is more foolproof. A display is useful for studies that are short term, or for inspection of conditions in real-time rather than the long-term. These types of study involve observing conditions as they change naturally, or by forcing changes to see the effects. For example, when commissioning a UPS system a load bank is applied and changes in waveforms are viewed as they occur to witness changes in shape or the occurrence of transients. This mode of testing requires oscilloscope display for immediate feedback. Similarly, another example is studying the inrush current of a motor or machine as it turns on to view peak currents for rise-time, dwell, and duration information. Such a study lasts only a few minutes. It must be pointed out that both black box and hand-held types can also utilize the PC as a real-time display in such applications, and may be preferable since the PC can save data for a report. A disadvantage of a tablet display is that it resembles a video game and invites tampering and theft.Over the years many connection schemes have been tried. The earliest monitors relied on screw terminals. If you ever come across a monitor that still uses terminal blocks do not use it. You will be exposed to high voltages terminal blocks are dangerous! Banana plugs are better since there are no exposed voltages, but in some designs jumper cables are required to configure channels for phase-to-neutral and neutral-to-ground connections. The possibility of shorting a phase to ground with a jumper exists. A better scheme uses single ended connections to eliminate the possibility of shorting a phase to a phase, or a phase to ground. Internal software in a full-disclosure meter configures the signals for wye or delta connections. The most stringent specification for these types of test equipment is CAT-IV. It means that they can withstand a 10,000 volt surge when connected to a 600V maximum service. By choosing a CAT-IV instrument you can feel safe using the meter anywhere in a facility at voltages below 600 volts.There are up to 5 different voltage connections to make along with up to 5 different current connections, so the potential for making wrong connections exists. Experience counts, but to help avoid wrong connections that can result in a wasted survey, various schemes have been developed. A display of phasors on a PC or built-in display to show phase rotation and current clamp polarity is useful to correct mis-connections. Most monitors now self-identify the range of a CT when connected, avoiding the need to set the full scale range manually and the possibility of making a set-up error. A recent breakthrough in the area of connection safety is software built in to the monitor that runs through a check of connections on all voltage and current channels to check for possible errors and advise the user. We are looking at an example of a real-time waveform captured by a hand-held monitor. This is an example of a snapshot of a waveform of voltage and current taken at an electronic load. This waveform captured by a hand-held meter is displayed on a PC. It illustrates how real-time waveform capture can assist the user to determine whether the voltage and current connections are correct and what the present conditions are. Notice in this example how the current is opposite polarity to voltage indicating the current probe is oriented the wrong way. The latest hand-held monitors sample at high rates, down to a few microseconds, and therefore do an excellent job of capturing waveform data to show harmonic distortion and transients. Multiple waveform snapshots can be stored simply by pressing a button just like a camera! Hand-held monitors can also be used like a multi-meter to measure instantaneous values. The display and marked function buttons on the keypad, along with the small size and weight, make spot checks of power values at panels and equipment simple and easy to perform with a hand held monitor.Making the correct connections is vital for a successful study. This is a list of the possible errors that can be made when connecting a monitor. As you can see its a long list and highlights the potential for error. Its not an exhaustive list. We didnt have the room to list the 70 different errors! It can be frustrating trying to get the connections correct. Frustration and confusion detracts from keeping users mindful of safety, particularly when working in hot or claustrophobic conditions such as confined equipment rooms. The ideal approach is where the user need only make the connections once, and therefore minimize the time that they are exposed to high voltages. The technology my own company has invented to check connections before you begin monitoring is called SureStart. It is intelligent software, built-in to the meter, that runs a check of the voltage and current connections against all the possible connection errors that we saw on the list on the previous slide. If it finds an error it will advise the user of a wrong connection in the display window. It is like having a built-in expert that guides the user to ensure correct connections with a minimum of connection and reconnections. By eliminating the frustration factor, and the time exposed to high voltages, safety is enhanced. This technology ensures a successful power survey the first time and every time.Another idea to ensure both correct and safe connections is the SafeConnect scheme. It involves a preconfigured set of connectors that ensure correct voltage and current connections whenever a power monitor is installed. It does require a one-time installation of the SafeConnect box and its associated voltage connectors and current transformers to the equipment being measured. But once installed it allows the user to make just one connection via a twist-on military style multi-pin connector to the monitor and all voltage and current connections are made correctly. This scheme is particularly useful in situations where regular or repeated monitoring sessions need to be made from time to time, such as at motor control centers, panels, or switchgear. In the next few slides Im going to focus on a new breed of power monitors, the hand-held type. Microelectronics has made possible high processing power and ample data storage in a small package, all at lower cost. We will look at these types of monitors for various types of power studies including power and energy analysis, power quality studies, as well as diagnosing problems with electric motors.

To distinguish the types of hand-held monitors its helpful to go back to the chart that categorized the types of commonly performed power studies. At the low cost end of the spectrum, hand-held data or power loggers can adequately address the most common type of study, logging of RMS volts and current. This accounts for a third of all studies. Examples of these studies would be when new loads or circuits need to be added to a panel, or when a particular circuit is extended or has other loads added to it. It is common to perform a before and after study to ensure that the circuit or panel has the capacity to accommodate the new loads, and that after they are added the circuit is not overloaded or affecting other circuits. Its important that the study provides minimum and maximum values, as well as a profile or plot of the RMS values over time so we can notice the behavior of when loads turn and off. The minimum and maximum excursion values of voltage and current over time are recorded. Another example would be to log incoming power at the service entrance to qualify the level of voltage provided by the utility. Another example might be to monitor an individual load, such as a motor or machine, to understand levels of inrush current as machines cycle on and off. Hand-held energy analyzers also log voltage and current, but also perform power calculations of watts, VA, VAR, and power factor and energy in KWh. Energy analyzers can address 60% of studies performed. Green is in! Businesses are looking for ways to reduce energy costs and help in the fight against global warming. Before energy savings measures can be applied, a base-line of energy consumption must be established, and energy guzzlers identified. Performing energy studies or audits will characterize energy use and identify opportunities for energy savings. Peak demand measurements along with a profile of watts over time may suggest ways of changing when loads are turned on or off, or when using power at different times would reduce costs. By knowing how much power is consumed a calculation comparison can be made to investigate whether a retrofit to a more efficient device is economical. The profile of how power is used may show that loads are left on when not needed, such as lights. Energy analyzer log files can be imported into a spreadsheet so that cost calculations or other calculations can be performed.The latest hand-held monitors are capable of handling all types of power studies for power quality, energy, and harmonics. They are both multifunctional and multifunction-ing; that is, all the measurements are made simultaneously. In other words you dont need to turn a particular measurement off to allow another, or need to configure the instrument specifically for harmonics, or energy, or power quality studies separately. This used to be the case with monitors that had limited memory and processing power where some functions had to be disabled to make room for others. Thanks to the advances in microelectronics and processing power we can now do all of these measurements at the same time.What are at the various methods of data retrieval from monitors to a PC? Data can be downloaded to a PC by serial communications, Ethernet, wireless, or by simply transferring an inexpensive memory card. Serial data communications is the slowest method. Ethernet is much faster and therefore better where very large data files are downloaded. Monitors are now available with wireless communications, such as Bluetooth. Their speeds of download are between those speeds of serial and Ethernet. Removable memory cards which can store hundreds of megabytes of data and the data can be immediately available in the computer by just plugging the card into the PC, without any wait for downloading. This is an example of a graph of a log file captured by a hand-held monitor. This graph shows the RMS voltage and current activity over time. It shows how current is changing with loads turning on and off, and the maximum excursions of current in blue. The RMS voltage, the black trace, is captured simultaneously with current and indicates good voltage stability when loads turn on and off.This is an example of the tabular data that represents a log file. This data can be exported to a spreadsheet for other analysis such as performing calculations, for sorting, or for other graphing functions.This is an example of a log file created by an energy analyzer from a survey made over a week. It shows the power recorded on the individual phases and the total power of all three phases. Hand-held energy analyzers also perform energy (KWh) and cost calculations. This graph shows the accumulated KWh from the same survey over a week. Complex rate structures can be applied by exporting the data to Excel.This is an example of harmonic content measurement showing the harmonic spectrum. This type of hand help monitor will capture harmonics up to the 63rd harmonic in both the voltage and current domains.Harmonic spectra can be viewed as tabular data, and can also be exported to a spreadsheet.Hand-held power quality analyzers can be programmed to capture voltage sags and swells by setting trigger levels. This graph shows a sag captured by a hand-held power quality analyzer. It has recorded the time of occurrence and the minimum value of voltage 96.2 volts.Sags can be shown as an RMS view as in the last slide, or as a wave-shape view as seen here. Wave-shape representations are more useful when the event is only a few cycles long. This graph also shows the time the event occurred and the minimum voltage that was recorded.Sag/swell event triggers in the current domain can be used to capture inrush currents of motors or machines as they turn on. This graph shows the rise-time and the peak current recorded for a saw motor. You will notice that the inrush current is approximately 5 times the run current.This is an example of a high speed voltage transient captured by a hand-held power quality analyzer. This monitor captures transients down to 8 microseconds at a sample rate of 2096 samples per cycle, and up to 1000 volts peak. The time of occurrence, the peak voltage, and the position on the sine wave have all been recorded. Zoom and expand tools are available to view such events in more detail.Here are options for hand-held meters to measure high voltages above 600 volts. Shown here are probes for connecting to services up to 5KV or up to 15KV with probes and hot sticks.It is estimated that two thirds of all power goes to supply electric motors. In industrial applications many motors run continuously 24 by 7, and are subject to cycling on and off may times a day. Consequently, motors, being electromechanical devices, experience wear and tear due to the stresses of operation. By performing periodic checks on a motors power consumption and analyzing the shape of the current waveforms it is possible to observe over time any degradation in performance and catch failures before they happen. An option is available for hand-held monitors that analyzes the current waveform of a motor for its harmonic content. The harmonic signature contains information on how well the motor is performing. Software on the PC performs an analysis on the motor waveform data and will detect incipient problems with armatures, bearings, and rotors. Both mechanical and electrical problems can be revealed by motor current signature analysis.The process is not yet complete! After the monitoring session is over the data is downloaded to a PC. This is the analysis phase and ultimately a report is generated documenting the surveys results. The finished report may incorporate the authors findings and recommendations, so report writers are designed to work with word processing programs such as Word. A report writer automatically tabulates and summarizes the data and saves the user from otherwise having to manually cut and paste the data, which can be very time consuming and tedious. Several report writer programs are now available from various monitor manufacturers. A good report writer utility summarizes the recorded values and lists in tables the maximum and minimum recorded values. Logs, and graphs are automatically included into a Word document that can be further edited, printed, or it can be emailed. Good PC software has analysis tools to zoom and expand areas of interest, measure minimums and maximums, and print with annotations and labels as shown in this plot of watts over time.This is what the end of the monitoring process looks like. A report that incorporates a tabular summary of the measured results along with graphs and plots.Report writers are a big time saver since a report can be compiled in just a few minutes, and the final report is professional-looking. Often these reports can be customized to narrow the report to a particular area of concern such as power quality events, or can be customized filter out unwanted data.In this version, a control panel is available to filter the output of the report to make it as broad or as focused as the user desires. Note that you can enter a nominal energy rate and the report will calculate energy use in $. If the utility rate is more complex, involving peak-demand charges for example, then the watts data can be exported to an Excel spreadsheet where complex rate structures can be applied. A unique feature of the PowerSight report writer is the ability to compile a report comparing two surveys done at different times, or at two different time periods within the same power survey.In the comparison mode the report writer calculates and displays the differences between the two survey periods. The comparison mode is ideal when performing before and after surveys. For example, verifying the behavior at a panel after adding new loads. Another example is verifying the energy and dollars saved after implementing energy savings measures. The first monitoring session is to audit energy use, and then monitoring a second time after measures have been applied.An important application for measurements of impedance on distribution systems is in performing Arc Flash hazard studies. The statistics are that 10 people a day go to hospital with Arc Flash burns and injuries, and about 3000 people a year are seriously burned or killed as a result of Arc Flash incidents. These incidents occur when electrical workers come into contact with high voltages and inadvertently create a short circuit with their bodies or tools. As a result the National Electric Code has a new requirement that panels and equipment must be labeled to warn and protect electrical workers.In conclusion, we assert that power monitoring is a process. The process starts with connection and set-up, then the collection of data, after which PC software is used to analyze the data and generate a report.Power studies are rendered invalid if the meter is set-up or connected incorrectly. Intelligent software solves this problem with pre-configured set-up files and intelligence to check connections before beginning monitoring.The most common power studies only require a simple data logger to log voltage and current activity, while energy analyzers that also measure power consumption and power flow can address 60% of power studies. When investigating power quality, sags and swells are the most common types of power quality problems. Harmonics and transient problems do occur from time to time but they are less common.A display on a monitor is most useful for short term investigations where it is important to view events and data as they occur, or soon after they occur. For long term monitoring the importance of the display diminishes if the data analysis is done on a PC off-line. Security is an issue, a display invites tampering and theft.With the advances in microelectronics, low-cost, hand-held monitors are available with high processing power, and increased memory capacity. They are attractive because of their portability, ease of use, and their rugged and compact packaging. Their capabilities extend to high speed transient capture, motor diagnostics and high voltage measurement.To complete the process, powerful software tools are available to analyze the data, automatically summarize the results, and generate a professional-looking report.