Current Transformer and Power Analyzer Question

[melvinlacia]

So here is the set-up:Three current transformers shall be clamped to the secondary side of a transformer. Then two power analyzers will be connected across two phase of the 3 phase system because I wanted to implement a two-watt hour meter method. The reason for the transformers is to scale the current to a new level that won't exceed the allowable current for the power analyzers which have 10 A capacity. Anyway, I am working on a power monitoring system.So, I don't have a clear idea on how the terminals of the CT's must be connected to the terminals of the power analyzer so that the system would work out well. Please help me out on this or any ideas that you can share. Your answers would mean a lot to me. Thank you very much.

 

[Knobhead]

Two analysers only need two CT’s. What were you going to do with the third?

Please remember never open circuit a CT under load. The high voltages induced in an open CT can cause fire or death.

 

[Engineer54]

Like Tony, ...i have no idea what your trying to achieve with the set-up you describe??

 

[MarkieSparkie]

Like Tony and E54 I'm puzzled as well. It would help us if you succinctly stated what you wish to achieve. Then we can recommend suitable test equipment and method to achieve you aim.

 

[Marvo]

I also would caution, as Tony says CT's can be dangerous if incorrectly installed. Can you attach a sketch of what you're trying to achieve. Are the units you're installing Power Quality Analysers or data loggers? Some makes and model numbers of the equipment would be helpful.

 

[rackie]

Actually this is the set-up, the 3phase delta connected sub-distribution lines are inserted into the CT's (ratio is 300:5 A). So the current from this lines are being transformed into 5A. The maximum current capacity of the power analyzer is 10A, so we are going to apply the power analyzers from the CT's using two-watt meter method. The problem is we don't know the connection. By the way, the input and output voltage of the power analyzer is 220Vac.

 

[melvinlacia]

Like Tony, ...i have no idea what your trying to achieve with the set-up you describe??

ok sir. I am going to clear things out to you. I am admitted that my description of the set-up was vague. But thanks to my friend Rackie.

so we are working on a power monitoring system.
1. So the the 3phase delta connected sub-distribution lines are inserted into the CT's (ratio is 300:5 A). Three CT's for three lines.
2. Two single-phase power analyzers (​

e-Gizmo AC power analyzer) will be paralleled to two phases of the line (e.g. A-C and B-C) to implement a two-watthour method. <you can also find the datasheet of that power analyzer from the e-gizmo site>

3. The power analyzer's capacity is only 10A. That is why, we used CT's.

Our problem: we are not sure on how this set-up is to be wired. We need your help. Thank you very much in advance.
​

- - - Updated - - -

Like Tony, ...i have no idea what your trying to achieve with the set-up you describe??

ok sir. I am going to clear things out to you. I am admitted that my description of the set-up was vague. But thanks to my friend Rackie.

so we are working on a power monitoring system.
1. So the the 3phase delta connected sub-distribution lines are inserted into the CT's (ratio is 300:5 A). Three CT's for three lines.
2. Two single-phase power analyzers (​

http://www.e-gizmo.com/KIT/PAnalyzer.htm) will be paralleled to two phases of the line (e.g. A-C and B-C) to implement a two-watthour method. <you can also find the datasheet of that power analyzer from the e-gizmo site>

3. The power analyzer's capacity is only 10A. That is why, we used CT's.

Our problem: we are not sure on how this set-up is to be wired. We need your help. Thank you very much in advance.
​

- - - Updated - - -

Like Tony, ...i have no idea what your trying to achieve with the set-up you describe??

ok sir. I am going to clear things out to you. I am admitted that my description of the set-up was vague. But thanks to my friend Rackie.

so we are working on a power monitoring system.
1. So the the 3phase delta connected sub-distribution lines are inserted into the CT's (ratio is 300:5 A). Three CT's for three lines.
2. Two single-phase power analyzers (​

http://www.e-gizmo.com/KIT/PAnalyzer.htm) will be paralleled to two phases of the line (e.g. A-C and B-C) to implement a two-watthour method. <you can also find the datasheet of that power analyzer from the e-gizmo site>

3. The power analyzer's capacity is only 10A. That is why, we used CT's.

Our problem: we are not sure on how this set-up is to be wired. We need your help. Thank you very much in advance.
​

 

[melvinlacia]

Like Tony and E54 I'm puzzled as well. It would help us if you succinctly stated what you wish to achieve. Then we can recommend suitable test equipment and method to achieve you aim.

I am very sorry if I have made you confused.
Maybe I should rephrase my description of the set-up. I hope this time, it would now make sense to you.

So here it is:


so we are working on a power monitoring system.
1. So the the 3phase delta connected sub-distribution lines are inserted into the CT's (ratio is 300:5 A). Three CT's for three lines.
2. Two single-phase power analyzers (e-Gizmo AC power analyzer) will be paralleled to two phases of the line (e.g. A-C and B-C) to implement a two-watthour method. <you can also find the datasheet of that power analyzer from the e-gizmo site>
3. The power analyzer's capacity is only 10A. That is why, we used CT's.

Our problem: we are not sure on how this set-up is to be wired. We need your help. Thank you very much in advance.