Portable Energy Monitoring

[spandanshoonya]

Hello
For Energy audit we need to monitor energies. But inserting ring type CTs every time is not convenient with an energy meter. Are there any clamp on CTs or flexible CTs available in 5A/1A output so that I can connect it with panel meters etc.Or what are other suppliers for portable energy monitoring devices ( 3ph).

 

[Skogsgurra]

Yes, there are several current clamps available. Just google to find some.

I have the same problem now and then and I use two core halves with the dimensions 30x20 Fe area and a 70 mm inner diameter hole. The halves are easily put around any cable and then kept in place with nylon strips.

For secondary winding, I customize a winding to suit the measurements. The winding needn't be very tight, so it is easy to use a set of "customized" windings to have a 10:1, 50:1 etc CT.

The advantage is that I do not need to have different sets of current clamps for different measurements. The accuracy is very good due to the large Fe area and the magnetic properties of the HiLite 100 micron plate used in the cores. The 100 microns reduce eddy current losses to very low levels so that they don't impair accuracy.

Gunnar Englund

http://www.gke.org

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Half full - Half empty? I don't mind. It's what in it that counts.

 

[waross]

I like that Gunnar. I was recently looking at an inoperative clamp meter. I didn't want try repairs but I hate to throw anything out. I am considering stripping it down to the core and doing the same as you are doing. I can compare the original turns with the original ranges to estimate the useful range of currents. It will be a smaller area than your core.

Bill
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"Why not the best?"
Jimmy Carter

 

[jraef]

I kind of developed a "thing" for flex core CTs lately, i.e. "Rogowski Coils". Yes, they're expensive, but they are oh so easy to use.


"You measure the size of the accomplishment by the obstacles you had to overcome to reach your goals" -- Booker T. Washington

 

[FreddyNurk]

Rogowski coils are awesome when you have access to them.

They don't, as far as I'm aware, work on DC current though, which can make them a little restrictive. Still the best method for quick measurements on multiple cables / phase too, providing your measurement equipment supports them.