How To Measuer High AC Current(1.1kA) With The Help of CRO

Hello Guest,

You don't advise what Voltage or frequency of the Electrical Supply.

Advise further, with

Kind Regards....

Are you using a current clamp meter? (By which I mean, why use a CRO?)

Can you explain where do you want to measure the current?

Is it in a cable/busduct/transmission line/switch board?

What is the voltage ?

If it is cable how many runs of cable are laid ?,What is outer diameter of the cable

If it is busduct crosssectional details are required.

Will it be one time measurement or permenant feature to measure the current.

It's fairly straightforward if the frequency is reasonably low.

(1) Make very sure that scope is floating. It's best to use a battery operated one but, if not, no grounds!

(2) Get an appropriate current shunt that has been calibrated and has a curve (no, it won't be perfectly linear) with it.

(3) Run the current through the shunt. Connect the scope inside the current connection (a good shunt has 4 way connection schemes).

(4) Read the scope. Refer to the calibration curve.

I've used this at 50 kA.

Should you be playing with 1 kA if this is a mystery?

Some of the methods include, 1) measuring the voltage across a high current resistor (shunt), 2) clamp-on ammeter 3) current transformer,4) a Rogowski coil. We use them all but tend to prefer the Rogowski coil because it is good for single current pulses (we use it to 500,000 amps), it isn't frequency sensitive, and it is a floating measurement. YMMV

Use an appropriately rated current clamp which has millivolt /amp output plug it into your CRO and read millivolts deflection.

Hello again, Guest.

It is interesting you haven't bothered to advise both Voltage and Frequency, as asked for in my earlier post.

Without knowing those, any answers given, are just guesses.

Reply here please, with

Kind Regards....