The Critical Importance of Redundancy
Power Monitoring is fundamentally different from other typical measurement activities in several ways:
- It is done over a long period of time, typically from 72 hours to one month.
- The installation and removal is done in potentially life-threatening circumstances (and if a panel is left open, there is potential for electrocution and arc flash throughout the entire monitoring process).
- It is not unusual that a formal permission and plan are required to install the analyzer and it is typical that it must be scheduled in advance, often weeks ahead of the study.
- It is not unusual that key business processes must be shut down during installation and removal of the analyzer, resulting in lost revenue (or extra costs if done outside of normal work hours).
All these circumstances lead to the same conclusion: The monitoring session absolutely must be completed successfully.
At intervals during the study and at the end of the study, the data must be correct and present, and the retrieval of that data must be successful. There is often no opportunity to repeat the study, and even if it can be repeated, the extra delay can be injurious.
PowerSight incorporates multiple means to eliminate error and confusion throughout the monitoring process, but also has built redundancy into key areas to insure success.
Here are the key areas of redundancy designed into every PowerSight monitoring solution.
Data Storage Redundancy
Every PowerSight analyzer comes with redundant memory capability. The internal memory storage is ample for all normal monitoring scenarios. In addition, the analyzer accepts standard SD memory cards that provide essentially unlimited data storage. As data is accumulated, it is written to both the internal memory and to the SD memory card. If one of these somehow gets corrupted or lost, the mirror image is available to preserve the data and the study can still be successful. If the internal memory of the analyzer fills up, due to being left monitoring for too long or due to an improper setup, PowerSight will, by default, start writing over the oldest data in the analyzer while still appending to the SD card. So no data is lost. We have seen instances where a customer sets up their analyzer to create a data record every second for a month. This resulted in over 2.6 million data records but nothing was lost because it was all appended in the SD memory card. An additional reliability feature of the SD card storage is that whenever a log file fills up to 65,535 records, the log file is automatically closed and a new log file is opened to receive the next 65,535 records. This way, if an error occurs on one of the files from a massive study, only one section of the total log will be lost: the lion’s share of the data will survive.
Since the logged data is compressed in the SD card files, even a memory card with capacity as low as 2GB provides essentially unlimited logging capacity.
Data Retrieval Redundancy
Every PowerSight analyzer comes with redundant methods to retrieve data from the analyzer.
- Bluetooth wireless connection: This feature comes standard on all PowerSight analyzers and loggers. Whether the analyzer is on your desk or installed in a powered panel, this is the default method of getting data files from the analyzer. In many cases, the Bluetooth connection can be initiated with the analyzer while it is locked inside an electrical panel, making it the safest and fastest method for getting preliminary study data while a test is underway. Whether the panel is open or closed, Bluetooth allows communicating from a safe distance without wearing cumbersome and uncomfortable PPE.
- USB port: All PowerSight analyzers above the PS2500 have a USB port for fast, secure communications via USB data cable. This can be very convenient for data transfer at your desk, or if you just want to transfer data to someone else’s computer without taking the steps to “pair” to the analyzer via Bluetooth. Please note that our analyzers are rated for 1000V CAT III which means that the USB cable is not to be connected to the analyzer while it is connected to live power, in order to maintain safety.
- SD memory card: Although we don’t tend to think of an SD card as a method of communications, it is often the fastest and most straightforward method for getting the data from the analyzer. Please note that our analyzers are rated for 1000V CAT III which means that the SD card is not to be inserted or removed while the analyzer is connected to live power, in order to maintain safety.
In addition, if you just need to do a spot check of operation or get summary measurements, all PowerSight analyzers have a feature-rich built-in display. After the test (or during test, while wearing appropriate PPE), users can hold the analyzer comfortably in one hand and view the data on the backlit screen.
- The PS5000 has a color graphics display that provides dozens of views of summary measurements and color graphs of the log, waveforms, phasors, harmonics, and more for fast comprehension.
- The PS3550 and PS4550 have extensive live measurements and summaries of all logged measurements (average, maximum, minimum for the study session) plus additional special measurements such as duty cycle, peak demand period, projected cost, and more.
- The PS2500 displays limited but very valuable measurements
Command and Control Redundancy
Every PowerSight analyzer has redundancy in methods to set it up and control its operation. There is value added to being able to verify and control the data setup parameters in the analyzer to ensure the study will have the results you need. Items that are often controlled are:
- Logging period (how often data is summarized into records for the log)
- Voltage, frequency, and power modes. There are a variety of modes of operation that enable or disable internal settings and AI “corrections under the hood” (like reversing a current probe in software, if it is installed backwards).
- Trigger thresholds. The power quality analyzers can have automatic setting of trigger levels or can be set to specific levels. It can be important to change the settings on-site to achieve the needed capture results.
- Logging parameters. Most analyzers allow deselecting measurement types from the log in order to stretch internal memory capacity. Specialty settings like “Start at <timestamp>”, “Stop at <timestamp>”, “Stop when full”, etc. can be useful. Memory can be allocated in the power quality analyzers between various file capture types to ensure you have the data output that matches your unique needs.
Almost always, there are multiple ways to make a change to the parameters in your analyzer when you need to.
Command and control can be accomplished with:
- Bluetooth, USB, Wi-Fi: All analyzers have a minimum of one of these serial communications methods available, each with its own advantages. You will be able to modify any of the analyzer’s operating parameters via serial communications to a laptop loaded with our PSM-A software.
- SD memory card: Data setups can be loaded into the analyzer directly from SD memory card. If you have 5 testing scenarios that you use, you can give each a descriptive name and load them onto the SD card inserted in the analyzer. Then at any time, you can securely change the setup or just refresh it to what you want, achieving certainty that it will operate in the way you need it to and eliminating the possibility that the study will have the wrong results.
- TestPlan Manager™: This is a unique feature developed by PowerSight that rests atop the SD memory card capabilities. If you create a multi-point test plan in TestPlan Manager™, you will be able to load the entire plan onto every SD card of every analyzer in the study. Then, the analyzers will all know the test points of the plan. When you start monitoring, you identify what test point you are located at and the analyzer can automatically configure itself to the needs of that test point. Additionally, all the data will be identified with the name of the test point and the test plan, so you don’t have to identify data sets by analyzer serial number and start time of the log. Even if the SD cards are pulled from the analyzers and mixed around, each one will report which part of the test plan it was located at, along with the corresponding data. This saves time and eliminates sources of error later.
- Keypad: The PS5000 allows managing almost every parameter of operation and logging from the keypad, eliminating the need of having a laptop in the field. The PS4550 and PS3550 allow changing all operating modes and setting the time/date from the keypad. Even the PS2500 with its single operator key allows making some rudimentary setup changes.
Operational Power Redundancy
- Every PowerSight analyzer comes with a 120V or 230V charger to power it. If you travel widely or require an outlet adapter that is not North American or Euro-style, universal chargers are also available.
- In many cases, it is ideal to have the analyzer locked inside an electric panel while monitoring, with no cables exiting. For that scenario, we have line-to-DC converter (LDC) power supply options that power the analyzer off the power that is being monitored (up to 600 Vrms) for unlimited monitoring.
- If you need to operate the analyzer for short studies or spot measurements, each PowerSight has internal battery capacity to operate for a full 8 hour shift (when fully charged).
- Each PowerSight is even able to operate off car/boat batteries for applications where there is no access to a charger supply, or extension cords are out of the question, or the voltage being monitored exceeds the capacity of an LDC.
In short, there is always a solution to powering your PowerSight analyzer, by design.
But power redundancy is required for when the power source for the charger or LDC drops out or is switched off. In those cases, PowerSight’s internal battery power will bridge any power failure for up to 8 hours. This means you can leave your analyzer with confidence that the monitoring session will succeed, even when power availability is uneven.
Redundancy in design is part of what makes PowerSight analyzers so unique and easy to operate. Data storage, data retrieval, control, communications, and operational power are all key elements to power monitoring that are deliberately backed up to eliminate costly errors. PowerSight owners know that when they take PowerSight onto a job, they can expect success.