Power Monitoring Best Practices
In addition to the Power Analysis Checklist (our guide to making sure you have the necessary equipment for a power analysis study), we have put together this list of ‘best practices’ for successful power monitoring. PowerSight is designed to give you success in almost any situation. Nevertheless, we’ve seen where monitoring sessions have gone wrong. As Murphy’s Law states, “If anything can go wrong, it will.” So regular users of PowerSight use “best practices”, processes that eliminate sources of risk or failure. This list may seem excessive; indeed, almost none of the steps below are required for success. But if you are doing a test that requires a scheduled facility shutdown or you have to drive far to the site (first to setup and then to get the data), you will never want to have to do the test over. A little extra time up front is a small price in order to greatly minimize any chance of failure.
Before the Job
1. Keep Core Tools Together
Keep your core system components together in a case so they are ready and you know where they are, in a pinch. If you are putting your system together in the first place, use the power analysis checklist to make sure you have obtained “the right stuff”.
2. Acquire Equipment Early
Two weeks ahead of the job, make sure the job doesn’t require any special accessories that you will need. If you have to buy something special (like a DC current probe) you need to allow time to get it purchased and delivered. If you are not sure what equipment you will need for the job, call or chat with us and describe your application. Our staff will help you craft a solution for your monitoring needs.
3. Arrange for a Power Down (if practical)
As far in advance as you can, determine if there will be a power down lockout for the circuits you will test and arrange for one if you can. It’s faster and safer to install on a securely powered down circuit and it may need to be arranged well in advance with the facility manager. If it will be live, you have time to be sure your PPE will be available and up to the risks involved.
4. Charge the Analyzer Ahead of Time
The day before your job, if you do not already keep your analyzer connected to a charger, attach it to have it fully charged for the job. If you have to set it up in a locked panel, you do not want any chance that it will run out of juice before power is available to it.
5. Have Your SD Card in the Analyzer
An SD card mirrors the memory in the analyzer and provides essentially unlimited storage to provide data redundancy and extra storage if the analyzer’s memory is exceeded to ensure that you will have the data from the study when you are done. Bluetooth and USB interfaces provide redundant communications and control but do not provide backup data storage. Always strive for redundancy and backup to battle Murphy’s Law.
6. Create a Custom Data Setup
If you ever use data setups other than the default, use PSM-A DataSetup Wizard™ to create them and save them both to your computer and to the SD cards in the PowerSight folder (or the root directory). Give them names that are descriptive for you, like “72HrOshpod” or “4Wk15MinMon”. This way you have your favorite setups always available and accurate. Keep them on both your computer to share with any PowerSight and on the SD cards in your analyzers where they can be loaded into the analyzer with ease prior to monitoring.
7. Use TestPlan Manager™ (if applicable)
If you are doing a multi-point study of more than five panels, breakers, or loads use the TestPlan Manager™ Wizard in PSM-A to document the plan and load it into each of the analyzers. This is the most efficient and error-free method of conducting a multi-point study.
8. Keep Extras on Hand
Remember: “redundancy is the fail-safe key to success”. Don’t be afraid to carry a light case with spare PowerSight charger, spare SD card, spare current probe, and a laptop with USB cable (and possibly even a spare Bluetooth USB adapter – BTA). None of these should be needed, but best practice is to be prepared with alternate means of communications and coping with missing/broken accessories.
Connecting the Analyzer
1. Let a Professional Install the Analyzer
Before we go any further, we assume you are an experienced electrician knowledgeable of working with live industrial power. If you aren’t, arrange for one to follow the rest of the best practices. Do not attempt to connect the analyzer to the power system yourself if you are not ready to take on the risks of injury or damage to you and the facility.
2. Power Down (if practical)
Best practice is to power down lockout before hooking up your analyzer. However, if you wear proper PPE for the arc flash danger and hook the probes up with care, you should be safe using PowerSight and its accessories. There are additional things to consider when hooking up to medium voltage.
3. Current Probes Before Voltage Leads
We recommend hooking up the current probes before hooking up the voltage leads because voltage clamps are easier to get knocked off during a tight installation. Since all probes are labeled at both ends, it is often easiest to hook up the probes and then attach them to the analyzer after getting the cables to lie the way you want.
- Note that for best accuracy, you want the place where the flexible current probes plug together to not be near the conductor it is monitoring. Ideally, it will be 90 degrees off from the point of contact with the conductor (that’s the position where we calibrate them). If using a clamp-type current probe, be sure the clamp is fully shut and there is no rust or impediment at the point where the jaws come together.
- Also note that each current probe has an arrow on it pointing in the direction from the source to the load. Install this correctly and the waveforms and phasor diagrams will look correct. However, the default data setup in PowerSight will turn them around in software to get the correct power and power factor measurements, so you do not need to worry about measurement accuracy.
4. Quickly Check Current Probe Pins
When plugging the current probes into the analyzer, quickly verify that the pins are straight and none are recessed in the socket (should never happen, but best practice is to quickly check). Carefully line up the plugs in their sockets and firmly press them fully into the connector as far as they will go. Use some “feel” to recognize if the pins are entering into their sockets before you force it. When installed properly, all probe connector bodies will be inserted the same distance.
5. Use a Line-to-DC Converter (if necessary)
If the circuit will not be powered down for more than 6 hours during the study, we recommend powering the analyzer with our LDCm or LDC4 (Line-to-DC converters). This accessory will power your analyzer from the power that it is monitoring. Since both the PowerSight and LDCm accessory are so small and flexible in their configuration, you can securely lock them both in most electrical panels. Locked panels eliminate issues with safety, theft, and tampering. Closed panels (without cables exiting) eliminate a power cord tripping hazard and the chance that the panel’s door will short the charger’s cable.
Line-to-DC Converter Mini (LDCm) connected to PS5000
Checking the Connections & Setup
1. Briefly Press On/Off Button
Don’t hold down the On/Off button when turning the analyzer on. Doing so will just shut the meter back off after the screen flashes. That delayed shutdown is an override feature that you should never have to use.
IF YOU ARE USING EFX6000 CURRENT PROBES:
When you first turn on the analyzer (or whenever you plug the probes into the analyzer), it will tell what measurement range the eFX6000s are set for (“10 to 6000A” or “1 to 150A”). Verify it is the correct range for what you expect your load to be. If it is in the wrong range, simply press the “No” key and it will switch to the other range. If you use the wrong range during testing, you may end up with data that is too small or too large to measure.
2. Go Through Connection Verification Procedures
- Each PowerSight analyzer has the patented SureStart™ Expert System Wizard to check the connections for you. We recommend you use this system, but first do a little checking of your own:
- If you have a PS5000, look at the phasor diagram on the analyzer or the virtual meter and perform the visual checks described below.
- If you are using a laptop to communicate with the analyzer you can capture a waveform and view it as a phasor diagram and perform the visual checks described below.
- If you have any of the models and are not using a laptop:
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- Press the Voltage key repeatedly to look at the voltage levels of each phase. Are they fairly balanced and close to what you expect them to be? (there are situations where you do not expect the voltages be balanced, but you should see what you expect to see).
- Press the Current key repeatedly to look at the current levels of each phase. Are they fairly balanced and close to what you expect them to be? (there are situations where you do not expect them to be balanced and the load may be substantially off while you are checking, but do the levels seem right).
- Press the Power Factor key repeatedly to look at the power factors of each phase. Are they fairly balanced and reasonable for the load you are monitoring? If you have current probes (or voltage probes) switched, you will typically find one power factor is what you expect it to be (e.g. 0.70, another is very high (e.g. 0.95) and the last is very low (e.g. 0.35). In such a case, the very high and very low voltage or current leads are probably switched.
3. Double Check with SureStart™
If the visual checkout of the previous step seems reasonable, follow up with a quick check with SureStart™. Press the Verify Connections key and it will automatically check the connections and advise of anything that might be a problem.
4. Verify Analyzer is Charging (if applicable)
If you have access to the analyzer, verify that its red charging light is lit. It can be charging or lit solidly. If you are looking at a virtual meter and your analyzer has a “gas gauge”, view it to verify that it is charging (assuming that power to the LDC or to the charger is on at that time).
5. Verify Correct Time & Date
Checkout the time and date in the analyzer and adjust as necessary. You want your data to have the correct timestamps.
6. Verify SD Card is Inserted Properly
When you turn the analyzer on, it should say Memory Card Updated. If not, the SD card may not be fully seated. You may need to remove it and insert it again. Sometimes new cards are a little tight the first few times they are inserted.
7. Load Your Data Setup to the Analyzer
If you have your desired Data Setup loaded on the SD card, this is the right time to load it. Your press the Setup key and it asks if you wish to load a data setup from the SD card. You will press Yes or OK and then select the correct one. At that point, you know you have everything loaded and ready.
- Just to feel completely safe, we recommend that you check the logging period and/or the time capacity of the setup in the analyzer to verify it is what you think it should be.
Starting Monitoring
1. Safe Communications with the Analyzer
If the analyzer is accessible while the circuit is powered up, wear your PPE and perform the following steps by pressing the keys of PowerSight directly. If the panel is locked, you should connect to the analyzer via Bluetooth and enter the Remote Control mode. In that mode, you can press the keys of the “virtual meter” and see the resulting screens of the “virtual meter” in order to do the checkout. In most cases, the powerful Bluetooth radios of PowerSight and our BTA accessory allow communicating with the analyzer while it is locked in a panel. If you cannot get good communications, you will need to crack the panel open a little to get the communications going. You should be able to stay outside the arc flash zone and do the following steps without needing arc flash PPE.
2. Start Logging
Whether working with the real analyzer or the virtual meter, press the Monitoring On/Off key at the upper left of the keypad. Be sure you do not need the the old data that is in the analyzer because when you start logging, it will erase the previous log in the analyzer.
The analyzer will warn you of the dangers of erasing the old log, but if you choose to proceed it will advise that you have started monitoring.
If you have a PS5000, the small box on the screen with the green word “Monitoring” will flash on and off every other second. If you have an analyzer with a 2-line display, there will be asterisks (“*”) at the start and end of the lower line flashing on and off every other second. If you do not see the flashing, you are not logging!
During Monitoring
1. Check on the Analyzer
If your monitoring session will last a week or more, come back after a day to download data via Bluetooth and maybe capture a waveform. If the study lasts for a month, it is often a good idea to come back after a week to pull out preliminary data. This not only give the customer something to look at, it verifies that the setups and triggers are working the way you intended and that the analyzer is getting the power it needs to keep operating. You never want to come back after a long study and find that you do not have the data you need.
2. Leave SD Card in While Logging
Never remove the SD card while monitoring. If the analyzer is writing to it at the moment you do that, there is potential to corrupt the card and lose all the data. Instead, stop the monitoring session and after it displays “Memory Card Updated”, then remove the SD card. After you insert the card again, you need to resume monitoring, using the option to “Append to the Existing Log”. This way the new data is a continuation of the previous data and no data is lost (except the measurements while logging was paused).
