Specifications of CT Output

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edozien
Posts: 1
Joined: Sun Apr 28, 2013 1:51 am

Specifications of CT Output

Post by edozien »

I would like to use EKM CTs with my own meters. I understood from the documentation that the output of the CT is a current that is proportional to the current in the wire passing through the core, with a maximum of 26.6mA. However when I monitor the raw output (white and black wires) with the ammeter of my meter it is consistently 0. I then tried to monitor the voltage accross the white and black wires. I get a measurement starting at 0.100006103515625 V but increasing in a way that does not appear to be proportional to the current in the wire passing through the core.

Do you have an API/specification for your current meters that can guide me? Or a circuit of how to make the voltage across the leads proportional to the current passing through the core?

Edozien
Jameson
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Joined: Fri Nov 04, 2011 7:42 pm
Location: Santa Cruz, CA
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Re: Specifications of CT Output

Post by Jameson »

Hello Edozien,

Make sure you are measuring the milliamp output of the CTs as AC (alternating current).

If you are using a 200 amp CTs and you pass 200 amps through it, the CT will output 26.6mA AC.

I would suspect that you would also see a much higher voltage (if your CT wires are open circuit). It is not going to be proportional to the current on the primary wire however.

I would look for voltage output CTs (3.33 volts is common) if you would prefer to measure the voltage. Voltage output CTs are designed differently than our CTs.

Thanks,
Jameson
EKM METERING
http://www.ekmmetering.com
831.425.7371
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