Power Monitoring is a Process
|Model No: PowerSight Meters|
Power Monitoring is a Process — PowerSight Meters are the Answer.
We assert that performing a power study is a process! Consider that any power study has a beginning, a middle, and an end that involves several activities. The meter does play an important role as a data collection device, but there is more to power monitoring than just the instrument. The process can be described as follows:
• Set-up and hook-up; making connections to the power circuit and programming the meter
• Collection of data with meter
• Analysis of data in PC and generation of final report - documenting results
Part 1 of the Process: Correct set-up and hook-up are vital to success.
A power study begins with connecting the monitor to power and programming it to capture data. If errors are made at this stage the survey is rendered useless before we have even begun! This results in a waste of time and money, and often creates client or customer dissatisfaction. The three reasons why power studies are unsuccessful are due to:
1) Bad planning
2) Incorrect connections
3) Incorrect set-up
Planning is essential before embarking on a power study. Before embarking upon a power study, good planning is vital. A good plan begins with a declaration of what we want to accomplish by defining the problem we want to solve. Here are 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, why?”
“I’m commissioning a UPS and need to verify it’s performance.”
“I want to perform regular diagnostics on our motors as part of a predictive maintenance program.”
And so on. 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 intended power study. You should begin planning by articulating what will be the “big result” when the study is complete.
To look at a simple 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 panel’s current capacity rating for safety. It would make sense to monitor the panel for at least 24 hours, or preferably, a week’s 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 and record when it reaches a maximum, and whether the maximum value recorded 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 panel’s capacity? Or have we inadvertently created a new problem such as voltage imbalance?
One of the uses of a power quality 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. A study will catch any gremlins on the power line and display the event waveform with time and duration information.
To reiterate, you must have a plan of action before beginning the study.
Connecting correctly and safely
One of the biggest problems in successfully performing power studies is discovering at the end of the study that the data is flawed or useless due to connection or setup errors. Here are just a few examples of common connections errors:
Voltages misidentified One, two, or three currents not connected to source
One, two, or three currents not connected to measuring system
Two voltage connections switched
One, two, or three voltages not connected
Two current sensors switched
Two or three connections to the same voltage
All voltages rotated one position left
Two or three connections to the same current
All voltages rotated one position right
One, two, or three current sensors backwards
One phase not present
Non-standard frequency due to power system problem
Two phases not present
Non-standard voltage due to power system problem
All currents rotated one position left
Neutral not connected to ground
All currents rotated one position right
Non-standard voltage due to improper loading
Three phases not present
Two phases shorted to neutral or ground
One phase offered as two or three phases
Non-standard phase shift between phases due to power system problem
One phase shorted to neutral or ground
Combinations of the above listed errors
Summit Technology has identified over 70 possible errors and has developed a technology called SureStartTM to eliminate connection problems. It is built-in software in the meter that checks the connections and advises of errors before you begin monitoring. SureStart makes these determinations regardless of the power system type, and in the presence of multiple connection or wiring errors, and presents the results in clear English statements. These PowerSight models:
PS4500 all incorporate SureStart™ software that checks the connections and advises you of errors before you begin monitoring to eliminate connection and set-up errors. For a complete description go here: SureStart
With Summit Technology’s PowerSight® meters you can create and save set-up files for different three-phase and single-phase monitoring scenarios. Thus, you can create a library of multiple files for recall to minimize set-up errors and save time reprogramming the meter before a study.
Summit Technology recently introduced three PowerSight models: the PS2500, PS3500, and PS4500 with CAT-¬IV safety ratings. CAT-IV is the most stringent safety rating for hand-held meters. CAT-IV means the instrument can withstand a 10,000 V surge at a 600 V service. You can feel safe using the meter anywhere in a facility at 600V or below. And with their Bluetooth wireless communications to a PC, you can safely observe waveforms and values on your screen remotely from a few feet away from dangerous high voltages.
Part 2 of the Process: Data measurement and collection.
Collecting data is the same for most all manufacturers’ meters. They all use similar digital-to-analog sampling and digital signal processing techniques, so there is no distinction between meters in terms of what they measure. Rest assured that PowerSight meters measure and record (log) all aspects of power including volts, amps, watts, va, var, power factor, total harmonic distortion (THD), frequency, energy (kWh) for all types of single-phase and three-phase power types. The Power Quality meters also measure sags, swells and transients.
However, there are significant distinctions with the PowerSight range of meters compared to other meters. They are the most portable monitors on the market; they fit in your hand and weigh only 1lb. Summit also offers the widest range of options and accessories such as high voltage probes (for 5KV and 15KV), power-line noise measurement, weatherproof case, converters to power the PowerSight meter from the line being measured, motor diagnostic software and other adapters.
Part 3 of the Process: Data analysis and reports.
After data has been collected the data is analyzed, and ultimately, the conclusion of the process is the generation of a report. Summit Technology’s PSM software for the PC has excellent analysis tools for viewing logs and events, and for zooming and expanding areas of the graphs. Tools are available to print any log with annotation, or export the data file to an Excel spreadsheet with just a couple of mouse clicks.
When it comes to documenting the results and creating a final report consider that there are up to 140 different parameters you may need to compile. Imagine having to manually cut and paste and tabulate all the measured results, going back and forth between Excel and Word for each phase and each parameter. You can appreciate it would be a frustrating, tedious, and time-consuming waste of productivity. The PSM software that comes with every PowerSight meter produces a complete written report, automatically. The Report Writer is a “wizard” that creates a report for you in just a couple of mouse clicks. You can filter the results to make your report as broad or as focused as you need, plus you can edit the text to add your conclusions. It generates the report in about a minute – and here’s the good news – the power study process is now complete!
To see an example report go here: Report
Conclusion: A better power study experience.
Now that we have looked at power studies as a “process” we can see that there are several considerations to keep in mind before selecting an instrument and before embarking upon a power study. The instrument, the tool to collect the data, is central to the process but the entire process involves hardware and software and good planning. At Summit Technology we have developed technology to give the user a satisfactory and successful experience in the entire process. To us this means getting the results the first time without error, to easily understand the data, and to present a final report in a professional-looking document, clearly and efficiently.
Summit Technology has a complete end-to-end solution for the entire process that delivers successful power studies every time.
Expert Help: Need advice on performing a power study, please contact us with any questions here:Contact or at (408) 982 9280
A pdf of this white paper can be downloaded here: Power Monitoring: Successful Studies Follow a Process