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Dent Frequently Asked Questions
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ELITEpro and DATApro
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SMARTlogger Instruments
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Software/Communications
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What's the difference between displacement and apparent power factor?
Displacement power factor is the ratio of the fundamental (60 Hz) real power to apparent power. Apparent power factor is a ratio of total real power (including harmonic component) to apparent power.
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How can there be a Power Factor of .87 on a 3-Phase Delta lighting load?
The line currents in a delta are shifted 30° compared to the line-line voltage. One line current will be shifted +30° and the other line current shifted -30° when compared to the line-line voltage. Since power factor is COS(theta), then COS 30° = .866. This will be true for the hardware channels. If the power sum channel (5 or 6) is used, the power factor for the whole load should be as expected.
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Why am I seeing negative Watts on one phase of a 3-Phase Delta system?
The line currents in a delta are shifted 30° compared to the line-line voltage. When connected to a load that has a PF of <.5 (>60°) (e.g. a motor not fully loaded) one line current becomes shifted >90° (30° +>60°) when compared to the line-line voltage. The other phase is shifted >30° (-30° + >60°). The COS of an angle >90° is negative, therefore WATTs = COS(theta)VA is negative for that phase. However, as with the power factor the sum of the watts in a delta should be positive. If not, check the CT orientation, one or both may be reversed. Also check to make sure the CT’s are referenced to the correct line voltages.
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Can I use the software to assist in verifying a current transformer connection?
Yes. If no current transformer is connected to a channel that is turned on, then a non-zero reading will be displayed. If the CT is connected but shows a '0' for a value, then the CT is probably connected but the monitored load is turned off. On the other hand if a constant value for current is displayed, a CT wire may have come off of the logger.
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ELITEpro and DATApro Instruments
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What is "Integration (or Recording) Interval"?
These are the periods that the logger will post data for. You can use 3, 15, or 30 sec., 1, 2, 5, 10, 15, or 30 min., or 1, 12, or 24 hour interval periods with the ELITEpro. All recorded values will have a time stamp using one of the above periods.
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What is "Waveform Sampling"?
This is the process of digitizing an analog waveform. The logger has a sampling frequency of 7.68kHz (128 points per waveform). The ELITEpro uses two 12 bit A/D to sample both current and voltage waveforms simultaneously. The data points from the waveform sampling are used for all calculations.
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Why will the ELITEpro not allow me to set my integration interval at 30 seconds?
Most likely it is because you are powering the instrument from the internal batteries. When running from the internal batteries the rate at which it will sample is once per minute. This preserves the batteries. When sampling on external power (9V transformer) the instrument senses the power and switches into a fast sampling mode (once every 3 seconds).
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I'd like to use my own CT's. What voltage output will be compatible with the DENT Instruments?
The CT inputs of the ELITEpro can handle a maximum of 500mV or AC or DC current. All of the CT's provided by DENT Instruments are shunted to output 0-333mVAC.
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I’ve got a remote site with no electrical and no phone line. How do I get the data?
The logger can use a external cell modem to provide data transfer from a remote location. Cell phone modems can be connected to the loggers serial port and provide a baud rate of 2400 baud. There is an option in PC Setup to set the software for extended timeouts for cellular communications. This feature will add timing delays and prevent dropouts. You can use AUTOPOLL, AUTOHOST or the manual dial features to retrieve logger data.
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How long does the battery last and is it replaceable?
Battery life for the PRO series instruments is generally 3 years. The standard instrument uses on lithium C cell and the modem instrument uses two lithium C cells. The batteries are in holders adn are easily replaceable. Note. Use the wall transformer whenever possible as this provides external power to the instrument and extends battery life.
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What is the modem capability?
The internal modem of the PRO series instruments is 14.4k baud.
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How will I know if I have sufficient memory to complete my study?
The best way to calculate the memory is in the first page of a setup table. Create the set up table in ELOG and view the calculated memory from the first page of the set up table. You can alter the table easily and see how it affects total memory.
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Can I use the ELITEpro to monitor 400Hz (military) loads?
Yes! Simply set the logger to 50Hz on the first page of the Set Up Table. At 400Hz, the logger will sample at 16 times per cycle. This method works very well as long as there is little harmonic current beyond the 7th harmonic (2800Hx).
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When I compare the ELITEpro measurements on three phase loads with another meter, I notice that the watts and VAR's agree but VA and Power Factor do not, why?
The usual reason is that the two meters are not calculating VA and Power Factor in the same way. Some meters include harmonics in the calculation and some do not. The ELITEpro can do both depending on whether the 2 watt-element method is being used (does not include harmonics) or the 3 watt-element method (does include harmonics).
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What is the difference between the ELITEpro™ and the DATApro™?
The ELITEpro is a poly-phase power meter designed to measure electrical loads up to 600v. The DATApro is a four channel logging device designed to measure data provided from outside sensors that can produce any of the following inputs; 4-20mA, 0-10VDC, electrical currents, temperature signals, or pulse signals.
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If I wish to monitor a remote site how do I retrieve my data?
Our PRO Series instruments (ELITEpro™ & DATApro™) can be ordered either with an internal modem or device server to be connected to a wired or unwired LAN system.
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Which instruments record harmonics and waveforms?
Only our ELITEpro™ can monitor harmonics and waveforms and allow you to view it in real time however, the ELITEpro™ will not store this data, it will allow you to take a snapshot to attach to a file.
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What are the memory capacities of the ELITEpro™ & DATApro™?
The standard memory is 128k (25,000 records) and the upgraded 512k memory (100,000 records) comes as an option. Memory capacity is a function of the integration interval, and recording flags set.
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Can I upgrade my memory at a later date?
Yes in the form of a factory upgrade. We also offer upgrades to internal modems. All factory upgrades include new EPROM's, new batteries, an electrical systems check, burn-in, and new software.
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What kind of computer operating systems will the ELITEpro ™& DATApro™ instruments work with?
Windows 95,98,2000, NT 4.0 or higher.
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What are the recording intervals of the ELITEpro™ & DATApro™ instruments?
3,15,30 seconds, 1,2,5,10,15,20,30 minutes, and 1,12,24 hours.
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What kind of current connectors are available?
Three types; split-core, clamp-on and flexible.
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Can I use CT's that I currently own with my new ELITEpro™ & DATApro™ instruments?
Only if they are shunted to 333mV's. This is the required input for both instruments.
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If power to the instrument is lost, does it stop recording and/or lose saved data?
Recording continues using the internal battery, however the sampling rate may change from every 3 seconds to once per minute to help extend battery life. Data that has been captured will always be stored regardless if the instrument goes completely dead.
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Can you do your own graph scaling with the DATApro™?
Yes.
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Can I have a monitored event trigger the start of monitoring?
No, however you can delay start until a specific date and time.
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How long does the battery last with the ELITEpro™ & DATApro™ instruments?
The typical battery life with these instruments is 3 years when the integration (data collection) interval is 1 minute or longer. The battery life can be as short as 1 month if the integration interval is set to less than 1 minute. The battery is user replaceable. Contact the factory for availability.
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What is the sampling rate of the ELITEpro™?
Sampling rate is the frequency measured in times per second that a logger reads each sensor. The ELITEpro™ reads once every three seconds (except when battery power is being used then it is once every minute). The integration interval is the period of time over which the samples that are read during the sampling rate, are averaged and then stored into the loggers memory.
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What is the waveform sampling rate for the ELITEpro™?
This is the number of points on a given waveform that are measured and the values used to calculate RMS volts, and watts. The ELITEpro™ samples at 128 points per cycle regardless of how often a channel is read.
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How do I connect my ELITEpro™ or my DATApro™ to my USB port?
Simply purchase our USB to Serial Port adapter.
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SMARTlogger Instruments
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Will my MAGlogger be able to sense a load if I just place it on the incoming line?
The MAGlogger can be used successfully without actually placing it on or near the actual device you are measuring. Sometimes you may need to experiment with the orientation of the logger to have it sense the load and indicate such with the LED or you may need to adjust the sensitivity. The MAGlogger will sense any signal greater than 40 milligaus. The MAGlogger will not sense a load if the L1 and L2 lines are close together as they tend to cancel out each other and yet if the load is large enough and the sensitivity on the MAGlogger is turned to its maximum sensitivity, it may sense the load.
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What type of information are the SMARTlogger™ instruments designed to provide?
Total running time, transition times, peak load times, kWh, and more.
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How many records can a SMARTlogger™ store?
Memory is rated by number of transition points (on's & off's) and is 8,000.
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Are TOU (time-of-use) instruments the same as SMARTloggers™?
Yes. TOU simply stands for time-of-use, while SMARTloggers™ is the trade name we give our series of TOU loggers.
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Does the MAGlogger require me to mount it directly on my dirty, hot, vibrating motor?
No, you can simply place it next to the incoming power line and the internal magnetic sensor will sense the flow of electricity and trigger the transition data.
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Is there an instrument I can use to simply monitor the running time of a stand-alone device that has a cord?
Yes, you may use the CTlogger™.
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If I use a MAGlogger™ to monitor a load, can I get kwH calculations?
Yes, by simply asking the software to set the kW scale factor then reading the results in the summary.
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How long does the battery last with the SMARTloggers™?
The typical battery life of the SMARTloggers is 5 years. The battery is user replaceable. Contact the factory for availability. (Note: Older SMARTloggers manufactured before April 2006 have a 7-10 year battery life, but are not user replaceable.)
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Software/Communications
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How do I scale the graphs to suit my purposes in the software?
By double clicking on the Y or X axis.
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How do I zoom-in when working with ELOG software?
Simply position the mouse pointer near the area to be zoomed. Hold the Control (Ctrl) key and left mouse button down at the same time, then drag the pointer to make a rectangle that covers the area to be zoomed. Let go of the mouse and Control Key and the graph will redraw a zoomed portion of the graph. The graph may be zoomed as many times as desired. use the View; UnZoom (Ctrl U), or the key to unzoom in reverse order of the zoom.
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When I am monitoring a load that requires more than one channel (such as a 3 Phase - 3 Wire Delta load) which channel shows my totals in my ELOG software?
When using more than one channel for one load, the results from each channel have to be added together to obtain the total power consumption. This is done using the computed channels 5 and 6.
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Do I need software, and does it have to be ordered separately?
Yes, software is used to program & start the PRO series and SMARTlogger ™ series loggers, in addition to retrieving and analyzing the collected data. If multiple loggers are used, there may not be a need for multiple copies of the software.
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Can I order the communication cables separately ?
Yes, the communications cable can be ordered separately or as part of the communication package. Communication cables for the weather-tight enclosure are special and must be ordered specifically when needed.
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Once I have the data, can I export it to a spreadsheet or database?
Yes, data can easily be exported to any ASCII programs like Excel® or Access®.
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How will I know if I have sufficient memory to complete my study?
The first page of the 'set-up' table automatically calculates memory capacity allowing the user to do 'what-if's'.
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Is the software the same for the ELITEpro™ and the DATApro™?
Yes, the ELOG software is used for both instruments.
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Is the software the same for all the SMARTloggers™?
Yes, the SMARTware software is used for all SMARTlogger instruments.
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