Understanding the basics of Energy Meter(CT & Shunt)

[shaswat]

I need to know the basic of energy meter. Last Day I opened the energy meter box just to know what inside works and how. Initially I find a shunt connected across the phase and a CT on the other hand. After a lot of goggling and discussion,I got a brief idea about the basics of energy meter but I want to know why they use CT. At internet it shows it is used for the isolatin purpose and to detect some tamper. But why shunt?. I don't get any information regarding shunt.
I want to know that what happened when we change the two terminal i.e. interchanging the shunt and CT with each other.
What happens if we use two CT or Two Shunt instead of a pair of Shunt and CT.

Any idea would be appreciated....

 

[FvM]

A shunt won't be connected across the phase rather then in series with the load (similar to a CT). So your observations seems to be wrong.

A single-phase energy meter would use either a shunt or CT for current measurement, but not both. Also a voltage divider to sense the phase voltage and some kind of power supply, e.g. a transformer or transformerless supply solution.

 

[shaswat]

This is what I got inside the meter. Here I got two elements.After internet search I got that one is CT and another is for the isolation purpose. In case I want to use two CT instead of one shunt & one CT. Is it possible to make a energy meter having two CT or two shunt. If I used two shunt then how to provide isolation to the meter? Or any new idea that enhance my knowledge would be appreciable.

 

[FvM]

Makes no sense at all.

 

[shaswat]

What do you means "no sense at all"

 

[FvM]

Even with much imagination, the schematic can't be related to the function of an energy meter.

 

[shaswat]

I just wnt to know which one is CT and which one is using for providing isolation

 

[FvM]

I don't see what a CT has to do with isolation in the context of an energy meter. A CT sensing both phase and neutral wire will be used in a RCD https://en.wikipedia.org/wiki/Residual-current_device.
The function won't be found in an energy meter.

If an energy meter uses a CT for current measurement, there should be only one wire sensed, usually phase. Alternatively, it can use a single shunt.