Smallest values that test the complete operating

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smallest values that test the complete operating range of the meter (up to 480V and class load). However, smaller values are possible if you are willing to restrict the test range. The test pulse duration of 25 milliseconds limits the minimum Kt value to a value large enough that the Test LED is not lit continuously at the maximum test load. NOTE: Changing the value of Kt does not affect meter readings or measurements. Changing Kt affects only the speed at which test pulses are generated. Smaller Kt values produce more test pulses and reduce test time. Test times shorter than 30 seconds are not recommended as shorter times can cause significant variability in test system results. The wide voltage range capability of the kV2c meter let’s you replace several ratings of traditional electromechanical meters with one 120 Volt to 480 Voltmeter. Each of these traditional voltage rating had a separate Kh. This means that we have several choices for Kt when testing a kV2c meter like a traditional electromechanical meter. The following recommendations should be kept in mind when selecting Kt. 1. Select the smallest practical Kt. Larger Kt values only slow down testing and do not increase test accuracy or change the test range. 2. If testing like an electromechanical meter use a Kt that matches the 120 Volt Kh for that meter. The meter can still be tested over the complete voltage range and will test faster than if the 480 Volt Kh is chosen. Table 3-3 Allowable Kt Range of Values Note: The maximum Kt values shown in Table 3-3 should not be exceeded. Exceeding these values may produce testing errors. 3.5.3 Watthour Test Procedure To test the meter, proceed as follows: 1. Note the meter Kt value listed on the nameplate. 2. Select the desired voltage and current level(s) on the test equipment. (Test voltage of 120V is assumed.) 3. Install the meter in the test socket, making certain that the socket is wired and/or configured for the appropriate meter form. 4. Align the optical pickup of the test equipment with the calibration LED. 5. Begin testing according to standard test procedures. Allow 15 seconds of settling time after applying voltage before making accuracy measurements (20 seconds if modem installed). 6. Check the meter calibration under three load conditions: full load, light load, and full load with lagging power factor. A minimum test time of 30 seconds is needed to reduce test uncertainty to a level compatible with the accuracy of the kV2c meter. (Check the instruction book for 57-120V 120-480V CL 20 0.15 1.6 0.3 4.0 CL 150, or 200 1.5 16 3.0 40 CL 320 2.1 24 4.5 60
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GEH-7285, kV2c Encompass Electronic Meter 3-10 Maintenance Instructions your test board or standard to determine the actual minimum test time. Standards with heavily filtered inputs may require longer test times.) 3.5.4 VArhour Testing GE kV2c meters are digital sampling meters. All quantities are derived mathematically from the same set of voltage and current sampled data used to compute Watthours. Therefore, it
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  • Spring '18
  • Electric power transmission, Power factor, Electricity distribution, smart grid, Meter Block Diagram

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