Energy Meter (KWH Calculation)

2 CT connection is quite ok. Check the CT directions and connection sequence. Dont what does it mean by it is not matching.

As initially indicated "110V" , the generator has to be Y connected (a neutral point). For delta the only available voltage would be 208V (line-to-line)

sandeepelect; it sounds like you might have a 3 phase 4 wire system, 200/110 volts 3 phase, 4 wire, then you will need a third CT on the on the wattmeter if it is a 3 element meter it will work. perry

Just a note for general information; the secondary side of PT's (potential transformers) is usually 110 volts for metering and control circuits. The primary voltage is not indicated by the secondary voltage, however the use of PT's indicates that the voltage is above 600vac.

Dear All,

Thanks for your comments,

But the energy meter was working properly before few days with 3Phase Voltage (110V) and 2 phase CT Input.

Now 1 Phase CT Input is missing. now i want to know That how i can measure exact Generation with the available Energy reading.

Generation Voltage is 11KV.

tHANKS ,

Sandeep Seth

sandeepelect,

This new information, that one of the two CT's was not working, sets up a completely different answer. There is not a method of calculating the exact amount of un-metered energy, but there are a few good 'guesstimates' available.

First if there is good historical data, the missing data can be interpolated by comparison with a past period of similar generation.

Second, one of the two meter elements commonly measures approximately 2/3 of the energy, and is known as the 'high registering phase'. The other meter element measures approximately 1/3 of the total energy and is known as the 'low registering phase'.

If a historical comparison identifies the working element, then the math to estimate is simple. Otherwise there is a method based on the vector diagram of the meter elements that will identify the high and low registering phases. Information about the normal running phase angle will be needed to assist in getting more exact estimations.

I would say that identifying if you are 1/3 or 2/3 low on measurement compared to normal is the most complete method of reconstructing the missing energy since it accounts for all the variables of the vector analysis estimate.

Regards, CJM

hi,

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