Metering CT

[AJustice]

Hi, I am looking for help locating an "off the shelf" outdoor rated CT. I am fairly flexible on the output and ratings. I would like to find "anything" low cost (<$150/unit) that could monitor load current 0-2000A @ 38kV with better than 5% accuracy.

 

[davidbeach]

And I want a car that gets 250 mpg. Doesn't mean that either of us will get our wish.

 

[rcw retired EE]

You won't be able to stay in that price range unless your 38 kV cable is insulated.

Most donut style CT's are rated for 600V and can only be applied at higher voltges if the high voltage wire is insulated or the CT is on an equipment bushing, like a transformer terminal.

 

[scottf]

A decent 38 kV CT in the US costs in the area of $2000/each.

You might be able to get a sensor for less, but you won't be able to monitor "0-2000A".

 

[marks1080]

What is your application? It is kind of odd to ask for such a device in that price range.

 

[AJustice]

My application is metering.

 

[waross]

Revenue metering or data logging metering.



Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[rcw retired EE]

Is the circuit overhead lines on a pole, underground cables in a trecnh, busbars on insualtors, insulated cables in cable tray, outdoor switchgear or something else?

How accurate does the metering need to be to achieve your goal? Is it revenue metering with money changing hands, check metering to see if the revenue metering is accurate or just an indication of the approximate loading on a circuit?

For example, if the goal is to mesure transformer losses by comparing the high voltage power to the low votlage readings, you need very high accuracy equipment and even then may not get good results. If the goal is only to see the load on a feeder within +/-10%, a different type of CT or clamp-on meter may be possible.

To help answer your question, a little more informaiton is needed.

 

[AJustice]

The unit would be used on outdoor switchgear to get "load" values. Not for revenue metering.

 

[davidbeach]

So, why not just get the metering from the relay, no need for an additional CR?