| Answers |
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1. |
Unpacking & Storage
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| 1.1. |
Contents, Unpacking & Storage - Procedure and Precautions
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| 1.1.1. |
Packed carton box contains - Operating Guide for DM5200 series meter, Limited Warranty Certificate, Test and Calibration certificate.
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| 1.1.2. |
First check the carton for signs of damage or liquid spills. If any damage is found, then you must lodge a claim with the transporter. In this case, please contact the transporter before proceeding with the unpacking; he may want his agent to be present. Please also read the Schneider Electric Conzerv Limited Warranty certificate received with the meter.
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| 1.1.3. |
Do not remove the protective plastic cover of your new Meters until the time of installation. Preserve the packing material. This will be required if the Meter needs to be shipped later for service or calibration. |
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2. |
Installation/ Commissioning
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| 2.1. |
Procedure of Installation & Commissioning
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| 2.1.1. |
Please go through the Operating Guide for DM5200 series meter supplied with each new Meter for instructions, installation/ commissioning. Refer wiring Diagram stuck on the case behind the bezel. |
| 3. |
Clarifications |
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3.1. |
How to get clarifications on product/product features? |
| 3.1.1. |
Call nearest contact point of Schneider Electric Conzerv for assistance
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| 3.1.2. |
Call our dealers across India, UAE, Thailand, Indonesia, Malaysia, Australia and Singapore. Visit our Products & Services section for details
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| 3.1.3. |
Call 1800 425 0555 (Toll Free No. All over India) for on line assistance. |
| 3.1.4. |
Write to contact@conzerv.com for details. |
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3.2. |
What is the meaning of Full Scale mentioned in the Test and Calibration certificates of DM52 series energy meter?
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| 3.2.1. |
Full scale is the product of V.Primary, A.Primary and root 3 at unity power factor. This is the value of kWh that meter will record for one hour in above said conditions.
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| 3.3. |
How is the accuracy of the Class 1.0 and Class 0.5 meters determined? |
| 3.3.1. |
The chart below gives the details of accuracy definition and the method to calculate the permissible error. |
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Class of accuracy |
Accuracy definitions |
How to calculate permissible error |
Standard conforming to |
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Class 1.0 |
+/- 1.0% of readings at 100% load, UPF & 0.5Lag and 10% load UPF |
Eg: 4 counts for full scale of 800.0 kWh and reading at 400.00kWh at 0.5Lag |
IEC61036 |
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+/-1.2% readings at 100% load, 0.8 Lead. |
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+/- 1.5% of readings at 10% load, 0.5Lag and 0.8 Lead |
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Class 0.5 |
+/- 0.25% of full scale + 0.25% of readings |
Eg: 3 counts for Full scale of 800.0 kWh and reading at 400.0 kWh |
IEC61036 |
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+/-1.2% readings at 100% load, 0.8 Lead |
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Note: Full scale is given by: Root 3 (1.732) * V primary * I primary
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Eg. 1. The meter specifications (as mentioned on the rear side of the meter) is PT Ratio - 415V/ 415V, CT ratio 500 A (5A or 1 A secondary is standard as ordered), then the Full scale in the kWh = 1.732 * 415 * 500/ 1000 = 359.39kWh
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Eg. 2. The meter specifications (as mentioned on the rear side of the meter) is PT Ratio - 33kV/ 110V, CT ratio 500 A (5A or 1 A secondary is standard as ordered), then the Full scale in the kWh = 1.732 * 33* 500/ 1000 = 28578 kWh
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Full Scale of 359.39 kWh correspond to 35939 counts (ignoring decimal points) |
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3.4. |
Can the 3 phase 4 wire meter (DM5240) be used for single phase measurement? |
| 3.4.1. |
Yes. Use R phase only for measuring. This may rarely result in a slight accuracy degradation of 0.2%. Alternatively, connect all 3 phases as per 3 ph 4 wire diagram (short Vr, Vy & Vb of the meter terminals and connect to line voltage and Neutral to the N of the meter terminals. Short S2 of Ir to S1 of Iy and S2 of Iy to S1 of Ib of the meter terminals and connect forward current signals to S1 of Ir and draw return current from S2 of Ib terminal of the meter), to the single phase circuit. Then divide the readings by 3. This will give more accurate readings. The wiring diagram is given below - |
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3.5. |
I have DM52 meter, how should I read the Energy consumption? What is this decimal point stuck on the front plate? |
| 3.5.1. |
The reading on the meter to be taken directly through the decimal point rather than calculating the reading using MF (say 0.1). E.g. the counter reading on the meter is 123456 now the reading shall be 123456*0.1 |
| 3.5.2. |
In conventional method, user has to multiply the reading, i.e., 123456 * MF of the meter to get the actual kWh. But with the decimal point, the reading can be directly taken, i.e., 12345.6kWh.
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| 3.6. |
Why does the Energy meter have a mechanical counter? Is this not a digital meter? |
| 3.6.1. |
Though this energy meter has electro mechanical counter (impulse counter) as display, the circuitry involved is Electronic. The counter updates by one count for each digital pulse input to it. For each counter updation the integration (Intg) LED blinks 8 or 10 times. For Integ LED to blink, the input given to it is a digital pulse emanating from the electronic processor card inside the meter. The intention of providing Electro mechanical counter is to retain the last recorded value under power failure condition which can not be stored in LED/ LCD display without battery back up (it makes the meter bulky, expensive and requires maintenance) |
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3.7. |
How does a DM52 energy meter display different Multiplying Factor (MF)? |
| 3.7.1. |
MF of the meter (0.01, 0.1, 1, 10, 100 or 1000) depends upon CT ratio or PT ratio and Full scale. If the CT ratio/ PT ratio is high then MF will be high.
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3.8. |
How is the Pulse Output used to interface with PLC? |
| 3.8.1. |
Pulse output from DM52 meters can be interfaced in to a process through a PLC or DCS for on line control of energy content in the process. With the PLC/ DCS self excited 12V or 24V digital input, external 24V supply not needed. The kWh pulses may also be used to derive the average kW information at the PLC. The information is available in the DM52 product leaflet, which is given below, under the heading 'Pulse output option application: |
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3.9. |
Why does the Intg LED blink 8/10 times per counter update? |
| 3.9.1. |
The Integ LED provides quick visual indication of energy integration. By running at faster rate, the user need not wait long till the counter updation in the meter. The blink rate is either 8 or 10 per counter update depending upon the CT ratio and PT ratios.
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| 3.10. |
What is meant by Burden of 0.2VA maximum per V/A inputs? |
| 3.10.1. |
Internal power consumption of the meter when connected to external CT and PT input. Lesser the burden per V/A inputs, more meters can be connected in series to the same CT/PT. |
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3.11. |
Is the counter in the meter tamper proof? |
| 3.11.1. |
Yes. This is a non-resettable counter. Hence tampering or resetting to zero cannot be done.
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3.12. |
Can DM 52 with Vin 120 Volts/ 100 Volts secondary be supplied instead of the 110V input standard? |
| 3.12.1. |
Yes, at extra cost. |
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3.13. |
Can the meter with 120V/100Volts, AC auxiliary be supplied instead of standard 110VAC?
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| 3.13.1. |
Yes. The 110Volts auxiliary supply already accommodates a range of 80 to 150 Volts. |
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3.14. |
Can DC voltage be given as auxiliary supply? |
| 3.14.1. |
DM5200 meter does not have this option. See product EM6400 for this requirement.
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3.15. |
How to read the meter specifications? |
| 3.15.1. |
The technical specifications such as PT ratio, CT ratio, auxiliary supply, class of accuracy etc. are printed on the terminal block (TB) label at rear side of the meter. |
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3.16. |
Can I change the CT Ratio of the meter at site? |
| 3.16.1. |
Yes. It is possible. Please contact our Bangalore Support Center for the CT ratio Spec changing chart.
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4. |
Problem observed during installation |
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4.1. |
Power ON LED of the Meter does not get ON. |
| 4.1.1. |
Check the auxiliary supply to the Meter. |
| 4.1.2. |
Auxiliary supply should be AC, 240V (range 170-300V) or 110V, if specially ordered (range 80-150V), 50Hz (range 45-65Hz). If the auxiliary supply voltage is below or higher than the range specified above, correct it. |
| 4.1.3. |
Check the fuse in the auxiliary supply route. If blown, identify the cause (short circuit etc. in the connection external to the meter) and correct it. Then replace the fuse. |
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4.1.4. |
tab-stops:45.0pt list 1.0in'>
Why does the Rev LED come ON? What should be the action by user? |
| 4.1.5. |
Rev LED gives the indication of Reversal of two or more CT connections; low PF or meter is operating at below 5% load. In such cases meter also may not indicate the correct Energy consumption. The CT connections should be connected to the meter with correct polarities and PF should be corrected to a healthy level of 0.5 and above and load should be above 5% of full scale. For more details please see 'Operating guide for DM5230/ 5240' supplied along with every DM52 energy meter. |
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4.2. |
Why does the Rev LED in DM52 series meter not go OFF even after the wiring and PF is corrected? |
| 4.2.1. |
The Rev LED 'remembers' reverse condition until the auxiliary supply interrupted. Hence it is necessary to switch off the aux supply (power supply) for 10 secs and switch ON after doing the correction in the wiring/ PF improvement. However, it is good practice to switch OFF the entire signal before correcting.
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5. |
Problem observed after few days/months |
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5.1. |
Integ LED of the Meter does not get ON/ Blink. |
| 5.1.1. |
Check whether Rev LED glow. If glowing, check and correct as per 4.6.2 above. |
| 5.1.2. |
Check the fuse in the Vin signal route. If blown, identify the cause (short circuit etc. in the connection external to the meter) and correct it. Then replace the fuse. |
| 5.1.3. |
Check the current flowing at each phase through Iin terminals of the meter. Check the panel CT for open circuit if no flow of current is found. Replace if defective. |
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5.2. |
Counter stopped incrementing.
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| 5.2.1. |
Check whether Integ LED blinks. If no, check and correct as per 4.7.1 above. |
| 5.2.2. |
If counter do not increment inspite of Integ LED blink, send the meter to nearest customer support center for rectification.
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5.3. |
There are few DM52 meters connected on distribution side. Total energy consumption (summation of all these meters) do not match with the meter fitted at incomer panel. Why? |
| 5.3.1. |
Difference of between 2 to 10% |
| 5.3.1.1. |
Losses in cables - Don't use broken wires; wire lengths should be as minimum as possible. |
| 5.3.1.2. |
Transformer losses - There is no correction actually possible but advisable to operate at suitable load levels, which gives high efficiency. |
| 5.3.1.3. |
Panel Current Transformer (CT) characteristics - Under 20-80% load CT performance would be normally better. |
| 5.3.1.4. |
Overrated (sized) current transformer. Use optimum size (ratio) CT's for better results. |
| 5.3.1.5. |
Accuracy of Current Transformer - Use CTs of better accuracy and quality (preferably class S CT's). |
| 5.3.1.6. |
Accuracy of reference meter (at Incomer Panel) used for comparison - The accuracy of reference meter should have better accuracy than the Meters down stream (Referee meters). |
| 5.3.1.7. |
Non Real time measurement error will lead to mismatch in the reading. As far as possible try to take the readings simultaneously. Tabulated readings to be compiled and compared once in a week or month to narrow down the non real time measurement error. |
| 5.3.1.8. |
Different sampling rate and updation frequency of reference meter and MUT - If the updation frequency of the display is different, measurement errors are likely as the readings recorded could be different at different point of time. |
| 5.3.1.9. |
Different Multiplication Factor (MF) for reference meter and MUT - Different multiplication factors in 2 sets of meters could cause additional error in readings. |
| 5.3.1.10. |
Incorrect programming of reference meter or MUT - This would result in wrong readings in the meter having in correct programming. Ensure 2 sets of meters have correct programming. |
| 5.3.2. |
Difference of between 11 to 30%. |
| 5.3.2.1. |
Interchange of one phase Current/ Voltage sequence at Meter Iin/ Vin terminals - Eg., Panel R phase CT/ PT wiring to be connected to Ir/ Vr with correct polarity (R phase of Meter) terminal on the meter. Similarly for Y and B phase also to be done. If required, correct the sequence. If reverse LED in the meter is glowing, switch 'OFF' the auxiliary supply for 10 secs. & switch 'ON'. |
| 5.3.2.2. |
Interchange of S1, S2 connection of one Current phases at Meter Iin terminals - Panel R phase CT wiring to be connected to Ir with correct polarity (R phase of Meter) terminal on the meter. Similarly for Y and B phase also to be done. If reverse LED glowing, correct the directions, switch 'OFF' the auxiliary supply for 10 secs. & switch 'ON'. |
| 5.3.2.3. |
System is operating at below 5% load of Full scale- Ensure that the load is above 5% of Full scale. If operated below the 5% of rated load, then reverse LED of meter is also likely come ON. |
| 5.3.2.4. |
System is operating at poor PF approx. below 0.5. Improve the system PF to above 0.5. If operated below the 0.2Lag, then reverse LED of meter is also likely come ON. |
| 5.3.2.5. |
Voltage signals not present at Vin terminals of the Meter for one phases after making the wiring connections - Ensure that the voltage signals are present at all phases at Vin terminals of the Meter. Check for ruptured fuse/connections of broken wires/ loose contacts etc. |
| 5.3.2.6. |
Current signals not present at Iin terminals of the Meter for one phases after making the wiring connections - Ensure that the current signals are present at all phases at Iin terminals of the Meter. Ensure no broken wires connections/no loose connections. |
| 5.3.2.7. |
Panel CT Ratio and Meter CT Ratio are not same - Ensure that the panel CT ratio and Meter CT ratio are same. Ex : Panel CT ratio is 500/5A and Meter CT ratio should be 500/5A. In case of EM3000/Em6400 meter meters should be programmed for PT/CT ratio matching system ratios. |
| 5.3.2.8. |
Panel PT Ratio and Meter PT Ratio are not same - Ensure that the panel PT ratio and Meter PT ratio are same. Ex : Panel PT ratio is 11kV/110V and Meter PT ratio should be 11kV/110V. |
| 5.3.2.9. |
Grounding is not done correctly for the following |
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a) Neutral of the panel. b) Neutral of the PT (if applicable) c) Earth of panel. |
| 5.3.3. |
Difference of between 31 to 65% |
| 5.3.3.1. |
Interchange of two phase Current sequence at Meter Iin terminals - Panel R phase CT wiring to be connected to Ir with correct polarity (R phase of Meter) terminal on the meter. Similarly for Y and B phase also to be done. Switch 'OFF' the auxiliary supply for 10 secs. & then switch 'ON'. |
| 5.3.3.2. |
Interchange of S1, S2 connection of two Current phases at Meter Iin terminals - Panel R phase CT wiring to be connected to Ir with correct polarity (R phase of Meter) terminal on the meter. Similarly for Y and B phase also to be done. Switch 'OFF' the auxiliary supply for 10 secs. & then switch 'ON'. |
| 5.3.3.3. |
System is operating at below 5% load of Full scale - Ensure that the load is above 5% of Full scale. Switch 'OFF' the auxiliary supply for 10 secs. & then switch 'ON'. |
| 5.3.3.4. |
System is operating at poor PF approx. below 0.5 for DM5230 and below 0.1 for DM5240 - Improve the system PF to above 0.5 for DM5230 and above 0.1 for DM5240. Switch 'OFF' the auxiliary supply for 10 secs. & then switch 'ON'. |
| 5.3.3.5. |
Voltage signals not present at Vin terminals of the Meter for one or more phases after making the wiring connections - Ensure that the voltage signals are present at all phases at Vin terminals of the Meter. Check for ruptured fuse/connections of broken wires/ loose contacts etc. |
| 5.3.3.6. |
Current signals not present at Iin terminals of the Meter for one or two phases after making the wiring connections - Ensure that the current signals are present at all phases at Iin terminals of the Meter. Ensure no broken wires connections/no loose connections |
| 5.3.3.7. |
Panel CT Ratio and Meter CT Ratio are not same - Ensure that the panel CT ratio and Meter CT ratio are same. Ex : Panel CT ratio is 500/5A and Meter CT ratio should be 500/5A. In case of EM3000/Em6400 meter meters should be programmed for PT/CT ratio matching system ratios. |
| 5.3.3.8. |
Panel PT Ratio and Meter PT Ratio are not same - Ensure that the panel PT ratio and Meter PT ratio are same. Ex: Panel PT ratio is 11kV/110V and Meter PT ratio should be 11kV/110V. |
| 5.3.3.9. |
Grounding is not done correctly for the following. a) Neutral of the panel. b) Neutral of the PT (if applicable) c) Earth of panel. |
| 5.3.4. |
Difference of above 65%
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| 5.3.4.1. |
Interchange of two or more phase Current sequence at Meter Iin terminals - Panel R phase CT wiring to be connected to Ir with correct polarity (R phase of Meter) terminal on the meter. Similarly for Y and B phase also to be done for 10 secs & then switch 'ON'. Switch 'OFF' the auxiliary supply for 10 secs. & then switch 'ON'. . Switch 'OFF' the auxiliary supply
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| 5.3.4.2. |
Interchange of S1, S2 connection of two or more Current phases at Meter Iin terminals - Panel R phase CT wiring to be connected to Ir with correct polarity (R phase of Meter) terminal on the meter. Similarly for Y and B phase also to be done. Switch 'OFF' the auxiliary supply for 10 secs. & then switch 'ON'.
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| 5.3.5. |
Check lists
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| 5.3.5.1. |
In case you require more assistance, fill up the checklist with relevant data and mail to Conzerv. The checklist template is given below -
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Check List |
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For difference in reading between Conzerv EM3000 series /DM52XX Meter and Reference Meter: |
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Sl. No. |
Description |
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1 |
Where Reference Meter is connected |
HT |
LT |
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2 |
Where Conzerv EM 3000/DM52XX Meter connected |
HT |
LT |
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3 |
Accuracy class of Reference Meter |
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4 |
Accuracy class of Conzerv EM 3000/DM52XX |
1.0 |
0.5 |
0.2 |
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5 |
What is the due date for calibration for Reference Meter |
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6 |
What is the due date for calibration for EM 3000/52XX (1 year from date of last calibration) |
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7 |
What is the Power Transformer rating |
Vpri |
Vsec |
Apri |
Asec |
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8 |
What is the approximate cable length from Reference Meter to EM 3000/DM52XX (in Mts.) |
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9 |
What is the sampling and updation rate of Reference Meter |
Sampling |
Updation |
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10 |
What is the Multiplication Factor (MF) of Reference Meter and EM 3000/DM52XX |
Reference Meter |
DM 52XX |
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11 |
Is any load connected directly to HT line.
If yes what is the amount of load. Amps |
Yes |
No |
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12 |
What is the start time and end time, date, month and year of Energy reading |
Start |
End |
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13 |
What is the percentage difference between two sets of Meter (i.e., Reference and EM 3000/DM52XX) |
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Note : The readings of Reference Meter and EM3000 / DM52XX could match at following conditions. |
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If, accuracy of Reference Meter is at least 4 times better than of the meter under test (DM52XX / EM3000).
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Reference Meter and DM52XX / EM3000 Meters are subjected to
same Vin, Iin signals.
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Updation and sampling rate is same in the two sets of Meters.
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Multiplication Factor (MF) of two sets of Meters are same
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